- Whole Tomatoes or Tomato Sauce?
- Best Roma Tomato Varieties for Canning
- Best Beefsteak and Slicing Tomatoes for Canning
- Best Cherry Tomatoes for Canning
- Tomato Acidity: Home Canning Tomatoes Safely – Understand Tomatoes Low Acid or High Acid
- Tomato Acidity Explained
- USDA Acidification Methods
- Background Information: Ensuring Safe Canned Foods
- Canning Tomato Products: To Acidify or Not To Acidify
- Canning tomatoes: whole, half and juice
- Canning whole or halved tomatoes (packed raw without added liquid)
- Canning tomato juice
- Selecting, Preparing and Canning Tomatoes
- Tomato Juice
- What are paste tomatoes?
- The problem with traditional paste tomatoes
- Growing tomatoes for canning sauces and salsas
- Best hybrid paste tomatoes for canning
- Best open-pollinated or heirloom paste tomatoes for sauces and salsas
- Feel free to mix types of tomatoes in your sauce
- Have you grown paste tomatoes for sauce or salsa at home before?
- Tips for Canning Tomato Sauce
- Tomato Harvest: Canning Beefsteak Tomatoes
- The Influence of Different Tomato Varieties on Acidity as It Relates to Home Canning
- Research disproves the myth of older tomatoes being more acidic
- Why does the myth still persist despite all the research?
- Green heirloom tomatoes
- An unsettling conclusion about tomato-canning history
- Further reading
Whole Tomatoes or Tomato Sauce?
We all love seeing those big beautiful heirlooms on farmers market tables. These days, they come in all the colors of the rainbow and every shape and size imaginable. A lot of what makes those varieties so tasty is their juice, which is perfect to add moisture and flavor to a salad or sandwich but will add work and frustration in a canning kitchen.
Fear not, heirloom lovers! Most people buying table tomatoes at a farmers market are looking for juicy heirlooms, but that doesn’t mean there’s not a lot of excellent canning heirlooms available for the home grower. While I’m sure grandma loved a good slicing tomato, she was keen enough to also select out low moisture, high flavor canning varieties and many of those seeds survive today.
Keep in mind that low moisture is only important when canning tomato sauce and paste. Low moisture Roma type tomatoes make the best sauce, but they come up lacking in flavor when canned as whole tomatoes. There are a number of big name heirloom tomatoes that are ideal for canning whole tomatoes, diced tomatoes and tomato juice.
Considerations for a Sauce Tomatoes:
- Low Moisture
- Small Seed Cavities
- High Yielding
- Dependable Yields & Disease Resistance
- Ripening Timetable (spaced out over the season or all at once)
Considerations for Whole or Juice Tomatoes:
- Taste after processing
- Firmness after processing (for whole tomatoes)
- Sized to Fit Jars (for whole tomatoes)
- High Yielding
- Dependable Yields & Disease Resistance
- Ripening Timetable (spaced out over the season or all at once)
Best Roma Tomato Varieties for Canning
Roma type tomatoes have been selected to have small seed cavities and low moisture, meaning that they require less cook time to create a thick, luxurious sauce. Roma varieties also tend to be high yielding, and a tough but easily removable skin combined with low moisture means that they’ll keep at room temperature for longer than most other varieties of tomatoes, allowing you to accumulate your harvest for several weeks before canning.
All around, Roma style tomatoes will produce the highest yield of sauce in the least amount of time. If you’re looking to can tomato sauce in bulk or make your own tomato paste, Roma tomatoes are your best bet.
The best Roma tomatoes for canning include:
San Marzano – (Heirloom, 80 days) Known for their sweet flavor, dense flesh and small seed cavities, San Marzano tomatoes are a traditional Italian favorite. They’re especially low acid, so be sure to add some kind of acid such as balsamic vinegar or lemon juice to your sauce before canning (or pressure can the sauce). Also excellent for sun-dried tomatoes. Organic San Marzano Seeds Available Here
Amish Paste – (Heirloom, 80 days) This thick-walled, meaty heirloom variety from Wisconsin produces flavorful 8 to 12-ounce fruits. Yields are high, and since it’s low moisture, much of that yield will come through in the final sauce. Amish Paste Tomato Seeds Available Here
Big Mama – (Hybrid, 80 days) A modern hybrid tomato that produces gigantic 5” long and up to 3” wide paste tomatoes. Low moisture and small seed cavities mean heavy sauce yields. Peels easily. Big Mama Tomato Seeds Available Here
Golden Mama – (Hybrid, 68 days) This hybrid tomato was bred for striking yellow flesh, as well as mild and sweet taste. It yields heavily, allowing you to make large batches of unique yellow sauce from just a few plants. Golden Mama Tomato Seeds Available Here
Best Beefsteak and Slicing Tomatoes for Canning
Large slicing heirlooms and highly productive greenhouse hybrids tend to contain a high percentage of moisture, which will need to be cooked off before your sauce reaches the appropriate texture. They also tend to contain large seed cavities, which will need to be removed as seeds will make the final sauce bitter.
Peeling tomatoes for home canning.
There are four good reasons to use beefsteak and slicing tomatoes for the sauce:
- Price – When in peak season, local farms will practically give these away by the case lot. When the full harvest comes in, it’s usually dramatically more than local markets can absorb.
- Availability – Cosmetically challenged fruits have little chance of selling, as consumers have their pick of the perfect specimens. Home canners can take advantage of this my contacting local farmers and buying them in lots as small as 20 pounds to as large as several hundred pounds for mere pennies on the dollar.
- Taste – Certain heirlooms also impart distinctive flavors and colors to a sauce that cannot be accomplished with the low moisture Roma’s on the market today.
- Color – Green zebra tomatoes can make a unique green sauce for example, and gold or orange variants can also make an especially dramatic presentation.
Here are some of the best beefsteak tomato varieties for canning:
- Ace 55 – (Heirloom, 80 Days) These thick-walled tomatoes are about the size of a tennis ball and stay firm even when cooked, making them a perfect choice for canning whole. They’re low acid, so be sure to add plenty of lemon juice for water bath canning. Ace 55 Seeds Available Here
Black Krim –(Heirloom, 80 Days) This Russian heirloom produces large yields of unique blackish-purple tomatoes with a rich flavor. Plants grow very large, be prepared with extra supports. Black Krim Tomato Seeds Available Here
Marglobe – (Heirloom, 73 Days) Developed by the USDA to be one of the first disease resistant tomatoes in the early 1900’s and treasured as a home canning tomato ever since. Plants yield heavily, and the fruits ripen all at once, making them ideal for large batch canning. Plants are also known for making a particularly flavorful canned tomato juice. Marglobe Tomato Seeds Available Here
Rutgers Original Tomato – (Open Pollinated, 76 days) Flavorful, medium sized 4 to 6-ounce fruits hold up well to canning. Originally bred from Marglobe. Rutgers Original Tomato Seeds Available Here
Best Cherry Tomatoes for Canning
While cherry tomatoes may seem an odd choice for sauce, given that they’re tiny seed bombs, and seeds in a sauce isn’t a good idea. However, they’re highly productive and contain a high sugar content as well as a distinctive pleasant flavor. If you have a food mill or chinois sieve that can readily separate out the skin and seeds, trying out a small batch of cherry tomato sauce is worth it for novelty value alone.
While even a dozen high yielding plants will not give you enough to make gallons at a time, a few pints with the fresh sweet zing of a cherry tomato will liven up any mid-winter meal.
Since cherry tomatoes are especially hard to peel and seed, use a food strainer to easily remove the peels and seeds from the pulp.
Sungold cherry tomatoes make a beautiful orange sauce with a distinctive flavor.
Here are some of the best cherry tomato varieties for canning:
Supersweet 100 – (Hybrid, 57 Days) Named for its huge clusters of fruit, with as many as 100 tomatoes on a single fruiting cluster. Extremely high yields mean that you’ll be able to collect enough tomatoes from a few plants to make a sauce. Organic Supersweet 100 Seeds Available Here
Sungold Cherry Tomato – (Hybrid, 57 Days) Exceptionally sweet orange fruits make a distinctive sauce. One of our neighbors grows a dozen plants to produce enough tomatoes for a big batch of bright orange tomato sauce. Sungold Tomato Seeds Available Here
Yellow Pear Cherry Tomato – (Heirloom, 75 Days) This heirloom produces large crops of bright yellow, pear-shaped cherry tomatoes. They’re very low moisture for cherry tomatoes, making them ideal for a sauce. The “neck” of the pear is all flesh, and the seed cavities are relatively small. That means larger yields of flavorful yellow sauce. Yellow Pear Cherry Tomato Seeds Available Here
What tomato varieties are the best?
Without a doubt, the tomato really is the most versatile plant in our garden – finding its way on to the dinner table all throughout the year in some way, shape or form.
It all starts each summer when the first few ripening fruits are plucked straight from the vine and devoured immediately in the garden – a tradition that occurs every year as those long Ohio winters and the wait for fresh tomatoes collide in an unrivaled bout of impatience! 🙂
Once that craving is satisfied – the tomatoes begin to find their way in to everything from fresh green salads, cucumber tomato and onions, penne pasta dishes, Margherita pizza, tomato soup, home-made salsa, ketchup, pasta sauce, tomato juice, pizza sauce , barbecue sauce, picante salsa and more. You get the point, right? The tomato rules!
And although all of the above are made from tomatoes – they are certainly not made from multiple tomato varieties. In fact, our garden and landscape are comprised of no less than 10 to 12 varieties every year – each of which serve at least one or two purposes in the kitchen. So that leads to the question – which ones are the best to grow?
Although there are hundreds if not thousands of varieties, the real key in choosing the right tomato for your garden is to know what you want from them come harvest time. Certain tomato types lend themselves better for juices, others for salsa and sauces, while still others are prized for their taste. Of course, the old rule of thumb applies here as always – grow what you love to eat!
Here are our favorite tomato varieties for Eating, Cooking and Canning:
So, if you simply love to eat tomatoes straight from the vine, or love them in fresh salads or on top of your hamburgers and sandwiches – here are some great varieties to try:
Black Cherry : If you like cherry tomatoes – then you will LOVE this heirloom variety. They produce tons of small round black and reddish fruit that are perfect for salads, salsa – or just eating one after another! They have a super-sweet rich flavor that can’t even be compared to those bright red cherry tomatoes you find in the plastic boxes at the grocery store. They are a prolific producer – and keep on growing and producing until frost.
Brandywine: This is a favorite among so many gardeners – and for great reason – the flavor is amazing and they make a great slicing tomato!
It is probably the most widely known and grown variety of heirloom tomatoes. They grow very large and dense, and can also be used for canning great pasta sauce.
Cherokee Purple: This is my personal favorite. It produces large, beefy tomatoes that have a dark deep red to purplish hue. When sliced open – they are meaty and make a mean tomato sandwich – but they also lend themselves perfectly for juice and pasta sauce – and they give beautiful color and taste to fresh or canned salsa.
Tomatoes For Cooking
When it comes to cooking with tomatoes, we look for tomatoes with great flavor and that are heavy-walled, and stand up to temps in the oven or on the stove top.
Ace 55: The Ace 55 produces a heavy load of tennis-ball sized red, thick-walled tomatoes. They are prefect for standing up to heat – and are a great tomato to use on the grill or on kabobs. They also make an excellent fresh sauce and are a big winner when it comes to those who like fried green tomatoes! They are a lower acid tomato – so not the best choice for when it comes to canning.
Red Pearl Grape (Cherry) Tomato : Much like the black cherry tomato above – these little cherry-style tomatoes are perfect for snacking on and for cooking in pasta dishes. Each plant produces hundreds of smaller tomatoes that are perfect for slicing in half and adding to sausage and penne or linguine dishes. They hold up perfectly in the heat and stay firm.
Valencia Orange Tomato: A fantastic producer in our garden last year – the Valencia Orange tomato produces loads of perfectly shaped tennis ball-sized orange tomatoes. Not only does this make the perfect tomato to use fresh in salads and salsa – but it cooks down perfectly to make fresh, super-sweet stove top pasta sauces. We have also found it to be THE best tomato to make fresh tomato soup with – it simply has out of this world flavor! It’s low acidity level is also a pleasant surprise for many, although it doesn’t lend itself well for any canning applications.
Tomatoes For Canning
When it comes to canning, you really want plants that have great flavor, are heavy producers – and have higher acidity levels for safe canning. These are all big winners when it comes to that!
In addition to the 4 varieties listed below – the Purple Cherokee and Brandywine listed above are also star performers in this category as well. They are simply perfect for adding great flavor to canned juice and sauces.
Amish Paste : This is the heirloom variety of what most know as a “Roma” style of tomato. Thick walled and great for making sauces and ketchup – this is a perfect tomato for canners! They are also great for salads because they stay nice and firm when sliced.
Roma : Roma tomatoes – the other cannign workhorse variety we plant each year. The Roma’s meaty substance makes it a great choice when it comes to thickening up our pasta and pizza sauce.
Black Krim : Another “Out of this World” tasting tomato. Just like the name implies – it becomes a dark blackish-purple when ripe. It originates from Russia, and has really become a favorite among heirloom tomato lovers. A word of caution – be prepared to support this one – it grows large and will take up some space!
Marglobe Supreme: This is a high acid tomato, and a big producer of tennis to baseball size tomatoes that are the perfect addition to the garden for a canning tomato. They are also well-known for making excellent juice!
For More Tomato Info See:
How to stake and cage your tomatoes on the cheap!
How to grow amazing tomatoes this year!
Growing heirloom tomatoes – experience real flavor
Happy Canning, Cooking and Eating! – Jim and Mary
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Tomatoes! The Best Tomato Varieties To Grow For Eating, Cooking and Canning Tagged on: amish paste tomato brandywine canning tomatoes cherokee purple tomato growing tomatoes heirloom tomatoes roma tomato varieties TomatoesGeorge’s favorite all-around tomato, ‘Big Beef.’ All-America Selections
Q: Can you tell me what is the best tomato to plant for canning and also a good eating tomato?
A: Ask a dozen different gardeners that and you’ll get three dozen different answers. So many excellent tomatoes are available, and everybody has his and her opinion.
A lot of people would tell you that paste tomatoes are best for canning because they have more meat and less water (in general). If you want to go that route, my personal favorite paste type is ‘Amish Paste.’ I also like ‘La Rosa’ and the old-time favorite ‘Roma.’ W. Atlee Burpee Co. (www.burpee.com) has a new variety called ‘Super Sauce’ coming out in 2013 that it’s touting as the “world’s biggest sauce tomato,” supposedly producing fruits up to 2 pounds each.
But I also like all of my favorite-tasting tomatoes canned, so there’s really none of the full-size varieties that just aren’t suitable for a jar in winter.
My favorite all-around, go-to tomato is ‘Big Beef.’ The yield and taste is good, the fruits are big, and the plants are about as disease-resistant as any I’ve grown.
Two of my favorite cherry types for fresh eating are ‘Sweet 100’ and ‘Sungold,’ but I wouldn’t try canning those.
Here’s a link to an article I did listing not only a few dozen of the best tomato varieties but the best varieties of all sorts of veggies:
Tomato Acidity: Home Canning Tomatoes Safely – Understand Tomatoes Low Acid or High Acid
Looking for Tomato Acidity: Home Canning Tomatoes Safely – Understand Tomatoes Low Acid or High Acid in 2020? Scroll down this page and follow the links. And if you bring home some fruit or vegetables and want to can, freeze, make jam, salsa or pickles, see this page for simple, reliable, illustrated canning, freezing or preserving directions. There are plenty of other related resources, click on the resources dropdown above.
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Are tomatoes low acid or high acid (acidic)? In short, they borderline, and whether they are acidic or not, for the purposes of home canning, depends upon the variety. In practice, it is a moot point: as long as you add a small amount of lemon juice (it won’t affect the taste) to each jar, it will always be acidic enough to be safe! Don’t miss: Answers to common tomato canning problems
Tomato Acidity Explained
Tomatoes borderline acidic, and it depends on the variety. Some are more or less acidic than others.
The USDA says:
Although tomatoes usually are considered an acid food, some are now known to have pH values slightly above 4.6. Figs also have pH values slightly above 4.6. Therefore, if they are to be canned as acid foods, these products must be acidified to a pH of 4.6 or lower with lemon juice or citric acid. Properly acidified tomatoes and figs are acid foods and can be safely processed in a boiling-water canner.
The University of Minnesota has a page dedicated to home canning tomatoes and says:
Researchers at USDA and at the University of Minnesota have found that most underripe to ripe, cooked tomatoes have a pH below 4.6. Unfortunately, a few varieties may have a pH above or close to 4.6. These include
- Ace 55VF,
- Beefmaster Hybrid,
- Big Early Hybrid,
- Big Girl,
- Big Set,
- Burpee VF Hybrid,
- Cal Ace,
- Garden State,
- Royal Chico,
- San Marzano. and
- there may be others!
Some of these are grown for commercial purposes and are not found in home gardens. However, safely canning these varieties requires additional acid for water bath processing or a pressure canning process similar to low acid vegetables.
USDA Acidification Methods
To ensure safe acidity in whole, crushed, or juiced tomatoes, add 2 tablespoons of bottled lemon juice or 1/2 teaspoon of citric acid per quart of tomatoes. For pints, use 1 tablespoon bottled lemon juice or 1/4 teaspoon citric acid. Acid can be added directly to the jars before filling with the product. Add sugar to offset acid taste, if desired. Four tablespoons of a 5 percent acidity vinegar per quart may be used instead of lemon juice or citric acid. However, vinegar may cause undesirable flavor changes.
Background Information: Ensuring Safe Canned Foods
Growth of the bacterium Clostridium botulinum in canned food may cause botulism; a deadly form of food poisoning. These bacteria exist either as spores or as vegetative cells. The spores, which are comparable to plant seeds, can survive harmlessly in soil and water for many years. When ideal conditions exist for growth, the spores produce vegetative cells which multiply rapidly and may produce a deadly toxin within 3 to 4 days of growth in an environment consisting of:
* a moist, low-acid food
* a temperature between 40° and 120°F
* less than 2 percent oxygen
Botulinum spores are on most fresh food surfaces. Because they grow only in the absence of air, they are harmless on fresh foods.
Most bacteria, yeasts, and molds are difficult to remove from food surfaces. Washing fresh food reduces their numbers only slightly. Peeling root crops, underground stem crops, and tomatoes reduces their numbers greatly. Blanching also helps, but the vital controls are the method of canning and making sure the recommended research-based process times found in the USDA’s Complete Guide to Home Canning are used.
The processing times in this book ensure destruction of the largest expected number of heat-resistant microorganisms in home-canned foods. Properly sanitized canned food will be free of spoilage if lids seal and jars are stored below 95°F. Storing jars at 50° to 70°F enhances retention of quality.
Food acidity and processing methods
Whether food should be processed in a pressure canner or boiling-water canner to control botulinum bacteria depends on the acidity of the food. Acidity may be natural, as in most fruits, or added, as in pickled food. Low-acid canned foods are not acidic enough to prevent the growth of these bacteria. Acid foods contain enough acid to block their growth, or destroy them more rapidly when heated. The term “pH” is a measure of acidity; the lower its value, the more acid the food. The acidity level in foods can be increased by adding lemon juice, citric acid, or vinegar.
Low-acid foods have pH values higher than 4.6. They include red meats, seafood, poultry, milk, and all fresh vegetables except for most tomatoes. Most mixtures of low-acid and acid foods also have pH values above 4.6 unless their recipes include enough lemon juice, citric acid, or vinegar to make them acid foods. Acid foods have a pH of 4.6 or lower. They include fruits, pickles, sauerkraut, jams, jellies, marmalades, and fruit butters.
Although tomatoes usually are considered an acid food, some are now known to have pH values slightly above 4.6. Figs also have pH values slightly above 4.6. Therefore, if they are to be canned as acid foods, these products must be acidified to a pH of 4.6 or lower with lemon juice or citric acid. Properly acidified tomatoes and figs are acid foods and can be safely processed in a boiling-water canner.
Temperatures for Food Preservation
Botulinum spores are very hard to destroy at boiling-water temperatures; the higher the canner temperature, the more easily they are destroyed. Therefore, all low-acid foods should be sanitized at temperatures of 240° to 250°F, attainable with pressure canners operated at 10 to 15 PSIG. PSIG means pounds per square inch of pressure as measured by gauge. The more familiar “PSI” designation is used hereafter in this publication (the Complete Guide to Home Canning). At temperatures of 240° to 250°F, the time needed to destroy bacteria in low-acid canned food ranges from 20 to 100 minutes.
The exact time depends on the kind of food being canned, the way it is packed into jars, and the size of jars. The time needed to safely process low-acid foods in a boiling-water canner ranges from 7 to 11 hours; the time needed to process acid foods in boiling water varies from 5 to 85 minutes. Keep in mind that each recipe is tested individually, so always follow the times and methods in the recipe.
Illustrated Canning, Freezing, Jam Instructions and Recipes
Canning Tomato Products: To Acidify or Not To Acidify
Why Acidify Tomatoes?
Tomato varieties have been bred for ease in harvesting; as a result many now have milder flavor and lower acidity than the ancestral tomatoes. Testing has shown that some current tomato varieties have pH values at or above pH 4.6; a few have values of pH 5 or even higher. Adding the recommended amount of lemon juice (or citric acid or vinegar) lowers the pH of all tested varieties enough to allow for safe boiling water bath canning. Acidifying all tomatoes now is recommended because it allows for safe processing in a boiling water bath canner (and for a safe short process in a pressure canner).
Some procedures from the USDA Complete Guide to Home Canning offer both boiling water and pressure canning options for tomatoes. For examples, see canning procedures for crushed tomatoes, whole or halved tomatoes, tomatillos, tomato juice, and tomato sauce (So Easy to Preserve, pages 51-56). Both the boiling water and pressure canning options require acidification. The boiling water and pressure alternatives calculated for canning these products are different time and temperature combinations that yield equivalent killing rates for molds and yeasts. These particular pressure canning options require acidity to ensure a safe product.
How About Salsas?
Salsas typically combine low acid foods (onions, peppers) and acid foods (tomatoes, fruits). Adding the recommended amount of acidity in the form of vinegar, bottled lemon juice or bottled lime juice is essential to produce salsas that can be safely processed in a boiling water canner. To produce shelf-stable salsa, follow the proven, tested recipes provided at the Home & Garden Information Center (HGIC), at the National Center for Home Food Preservation, or in So Easy to Preserve (pp. 66-76). If your friends want to make a family salsa recipe, ask them to refrigerate it or freeze it.
And How About Tomatoes with Okra or Spaghetti Sauce?
Neither vinegar nor lemon juice are included in recipes for canning tomatoes with okra (p.54) or canning spaghetti sauce (pp. 63-64) in So Easy to Preserve. These recipes require pressure canning because of the low acid ingredients. Adding meat to spaghetti sauce lengthens the required pressure canning process. The recipes for tomato-vegetable mixtures in So Easy to Preserve (pp. 54, 63, 64) or on the HGIC were tested for pH and heat penetration and safely include shorter processing times. However, the recipes and preparation steps must be followed precisely. If tested recipes for tomato-vegetable mixtures are not used, then the mixtures should be pressure canned according to instructions for the vegetable in the mixture with the longest processing time.
- E.L. Andress and J.A. Harrison. 2006. So Easy To Preserve. Georgia Cooperative Extension/The University of Georgia.
- HGIC 3340 Preserving Tomato Sauces & Ketchup
- HGIC 3360 Preserving Tomato Products (Juice – Salsa – Sauces – Tomatoes with Okra)
- How Do I? …Can Salsa. National Center for Home Food Preservation (includes multiple salsa recipes) http://nchfp.uga.edu/how/can_salsa.html
- USDA Complete Guide to Home Canning. 2009. Can be downloaded from the National Center for Home Food Preservation at http://nchfp.uga.edu/publications/publications_usda.html
Canning tomatoes: whole, half and juice
Canning whole or halved tomatoes (packed raw without added liquid)
- 21 pounds (average) yields a canner load of 7 quarts.
- 13 pounds (average) yields a canner load of 9 pints.
- 53 pounds (1 bushel) yields 15 to 21 quarts or 3 pounds (average) per quart.
- Large pot of boiling water for removing tomato skins.
- Large container of ice-cold water.
- Canning equipment (see Home canning basics).
- Wash tomatoes.
- To remove skins: Dip in boiling water for 30 to 60 seconds or until skins split, then dip in cold water; skins should slide off easily.
- Remove cores and leave whole or cut in half.
- Add additional acid to jars according to the acidification chart above.
- Add 1 teaspoon salt per quart to the jars, if desired.
- Fill jars with raw tomatoes, leaving ½ inch headspace.
- Press tomatoes in the jars until spaces between them fill with juice.
- Leave ½ inch headspace.
- Adjust lids and process.
Processing times by method
- Boiling-water bath: pints or quarts – 90 minutes.
- Dial-gauge pressure canner: pints or quarts – 25 minutes at 11 PSI or 40 minutes at 6 PSI.
- Weight-gauge pressure canner: pints or quarts – 25 minutes at 15 PSI or 40 minutes at 10 PSI.
The National Center for Home Food Preservation has over 30 tomato product canning recipes. Choose processing times and methods for Minnesota altitudes of 1001-2000 feet.
Note: Processing times and pressures in this publication are for Minnesota altitude ranges.
Canning tomato juice
- 23 pounds (average) yields a canner load of 7 quarts.
- 14 pounds (average) yields a canner load of 9 pints.
- 53 pounds (1 bushel) yields 15 to 18 quarts or 3¼ pounds (average) per quart.
- Wash, remove stems and trim off bruised or discolored portions.
- To prevent juice from separating, quickly cut about 1 pound of fruit into quarters and put directly into saucepan.
- Heat immediately to boiling while crushing.
- Continue to slowly add and crush freshly cut tomato quarters to the boiling mixture; make sure the mixture boils constantly and vigorously while you add the remaining tomatoes.
- Simmer 5 minutes after you add all pieces.
- If you are not concerned about juice separation, simply slice or quarter tomatoes into a large saucepan; crush, heat and simmer for 5 minutes before juicing.
- Press heated juice through a sieve or food-mill to remove skins and seeds.
- Heat juice again to boiling.
- Add additional acid to jars according to the acidification chart above.
- Add 1 teaspoon salt per quart to the jars, if desired.
- Fill jars with hot tomato juice, leaving ½ inch headspace.
- Adjust lids and process.
- Boiling-water bath: pints – 40 minutes; quarts – 45 minutes.
- Dial-gauge pressure canner: pints or quarts – 15 minutes at 11 PSI or 20 minutes at 6 PSI.
- Weight-gauge pressure canner: pints or quarts – 15 minutes at 15 PSI or 20 minutes at 10 PSI.
Note: Processing times and pressures in this publication are for Minnesota altitude ranges.
“I can find room for one more tomato plant…” Just…one…more…plant.
Do you say that every year too?
My tomato obsession really took off about three years ago when I began starting my own tomato seeds. The varieties you can find when you buy seeds instead of already started plants are just incredible (at least in my neck of the woods). If you’ve only ever gotten tomato plants from a greenhouse, you might be in for a big surprise!
For a long time I was intimidated by starting my own seeds, but now that I have done it I can’t believe I waited so long. Really, anyone can do this. It is worth looking into. I can’t keep a house plant alive for anything, but I can start seeds!
With so many tomato varieties, it is hard to know which ones to choose.
As Chandler would put it- “my wallet’s too small for my fifties, and my diamond shoes are too tight!”
Too many tomato varieties is a really a good problem to have I suppose, but it can be a little overwhelming.
First you have to know what your goals are…
Do you just want fresh tomatoes to eat in the summer?
Will you can them? Make sauce, salsa or diced tomatoes?
Do you want to impress your friends with your tomatoes? I do.
How do stuffed tomatoes and sun-dried tomatoes sound to you?
You can have all of these things! Your tomato dreams are about to become reality…
But first! Do you know your Heirloom Tomato Name?! Mine is “Little Schmidt Celebrated Traveler.”
If you are a garden nerd, click here to find out your own Heirloom Tomato Name, courtesy of Seed Savers Exchange!
A few tomato-related things to keep in mind:
Hybrids & F1
Hybrid or F1 plants might be really cool, but you will not be able to save seeds from them to use for future years. Well…you can, but it will likely produce something totally different than its parent tomato.
An heirloom plant is one that has been cultivated for years and will keep their traits from generation to generation. These are the seeds that you can save yourself and plant year after year.
Determinate vs. Indeterminate
I saw this label for many years before finally looking it up. Determinate tomato plants, often called “bush” varieties will grow to a certain height and then set their fruit all at once, with most ripening in a 1-2 week period. Indeterminate plants will keep growing, setting and ripening fruit throughout the whole season until killed by frost.
Plant “early” varieties to get fresh tomatoes a couple weeks earlier than everyone else. I often see these as hybrids, but there are also heirloom varieties that ripen at 50-60 days instead of 70+. Try Stupice, or check out this collection from Gary Ibsen’s Tomato Fest!
Cherry & Grape Tomatoes
The least temperamental and perhaps the most fun. I love these because even in a “bad tomato year” they still come through for me. If the rest of my tomatoes are cracking and molding on the vine, I can always count on the cherries.
What to do With Cherry & Grape Tomatoes
Cherry tomatoes are my favorite for adding to big garden lettuce salads, which we eat all summer long.
Halve a few pounds of cherry tomatoes and mix with chopped shallots, olive oil, and balsamic vinegar to make an incredible bruschetta topping.
Skewer and grill them!
Slow roast them in the oven with olive oil and garlic, until their flavors are concentrated. Use as a topping for, well…anything, or freeze them in this state for later. Love these on chicken or in vegetable salads, like fresh broccoli and roasted tomato salad.
When we start to build up an excess and have more than we can eat, I will fill up quart freezer bags full and stash them in the freezer. No preparation of any kind, just put them in the freezer raw and whole. I later use them in soups, crockpot dishes, omelets, sautéed with garlic and put on top of chicken, or sautéed with green beans and bacon.
My Cherry & Grape Tomato Picks:
I grew these for the first time last year and they will definitely be coming back! A really gorgeous tomato, flavorful and sweet. They have shades of brown, green and red all at the same time.
I liked these last year; they are tiny but incredibly prolific, and are the most beautiful springtime yellow color. I especially loved them for salads. Maybe not the most practical tomato because the overall volume isn’t as much as other, larger varieties, but these are fun.
These fall under the category of “impress the heck out of your friends!” They were developed by Wild Boar Farms, whose passion is “breeding new extreme, exotic tomato varieties.” I just love what they are doing and I can’t wait to try these this year! Check out all their unique varieties and buy seeds here. (photo courtesy of Wild Boar Farms)
Pink Bumble Bee
Described as “fire-engine red with golden striping, these tomatoes are crack-resistant and weather tolerant.” They look stunning and I decided I just have to try them this year. I’m a sucker for a unique looking tomato. (photo courtesy of rareseeds.com)
Others to try…
Chadwich Cherry: delicious sweet flavor, huge yields, disease resistant.
Blondkopfchen: small golden yellow fruits in large clusters, sweet excellent flavor.
Organic Matt’s Wild Tomato: deep red cherry, smaller than average, thinner skin.
Roma & Paste Tomatoes
These are our work-horse tomatoes. We make a lot of chili with diced tomatoes, crockpot recipes with homemade salsa as the base, and simple Italian sausage dinners doused in homemade marinara. Paste tomatoes are definitely the most important tomatoes we grow in terms of food storage.
What to do With Paste & Roma Style Tomatoes
Most of your canning needs, of course!
This is also my preferred variety for making sun-dried, oven-dried, or dehydrated tomatoes. They have the fewest seeds and are relatively dry inside, and make nice, meaty dried tomatoes.
When making fresh salsa (pico de gallo) during the summertime, I like to use a base of this variety plus an additional different colored “eating variety” for added flavor and color. I like that this variety doesn’t make my salsa too runny.
Aaand, this category usually includes many of the “pleated” varieties, which are my absolute favorite for stuffing, as in, making stuffed tomatoes. See the “Gehzahnte” below.
My top Paste & Roma Tomato Picks:
This will be my first time attempting this variety. I have very high hopes for my marinara this year! The classic Italian tomato. (photo courtesy of rareseeds.com)
I liked the shape of this tomato and the description of “high yields of richly flavorful plum shaped tomatoes.” (photo courtesy of rareseeds.com)
This is the stuffing variety I was talking about (there are other pleated varieties available too). The seeds and ribs are all in the center, and easy to remove, leaving the perfect cavity for filling with whatever you choose. (photo courtesy of rareseeds.com)
Others to try…
Amish Paste: shape varies from round to oxheart, bright red, meaty and juicy.
Organic Gilbertie Paste: long, slender 7″ fruits with very solid flesh.
Large Eating Tomatoes
These varieties can have have just a few large seed cavities, or be spotted with lots of seed cavities. They come in all different shapes and size- from barely bigger than a cherry tomato, two a two pound mammoth! They are often more round in shape than say, a Roma variety.
What to do With Large Eating Tomatoes
These are dual purpose for me. Of course we eat them fresh on just about anything- tomato and basil salad with salt and lots of fresh cracked black pepper, on lettuce salads, fresh salsa, on top of grilled chicken breast and hamburgers.
I also use these for canning, specifically for diced tomatoes. They have such great flavor that I can’t resist. Being juicier than the paste varieties, they produce canned diced tomatoes that have a little more liquid in them, which I actually like, especially for chili.
These are a great “sandwich” tomato, giving the best thick, meaty slices.
My first choice tomato variety for making fresh tomato gazpacho in the hot summer months.
Also my first choice for homemade tomato soup. Try this recipe from The Prairie Homestead!
Being the largest, juiciest tomatoes, this type is perfect for tomato juice, which you can freeze or can as well!
Two words: Bloody Mary.
The different variety of colors and flavors are out of this world, which makes this a great variety for impressing your friends and family!
My Top Large Eating Tomato Picks:
I just love these! The flesh is mostly yellow with streaks of red and when they are cooked down the colors combine to form the most incredible “Golden Diced Tomatoes” as I call them. Also, very large and quite prolific.
German Red Strawberry
Typical 1lb fruits are shaped like gigantic strawberries. A German heirloom with a rich, sweet flavor with a only a small amount of seeds and juice. (photo courtesy of rareseeds.com)
I love the name, first of all. I like to have at least one variety of green tomato around and I think I’ll try this variety this year. The “flavor is rich and superbly sweet.” (photo courtesy of rareseeds.com)
Another product of Wild Boar Farms. This tomato is described as a meaty pink beefsteak with blue top. Another absolute stunner with many desirable traits! (photo courtesy of Wild Boar Farms)
Others to try…
Mortgage Lifter: I like the name! Just a good old-fashioned tomato.
Bradywine: Another classic heirloom tomato; large with a good balance of sugar and flavor!
These are not hard and fast tomato rules at all- in reality you can use any type of tomato for just about any application! I think you will just achieve the best results from pairing the right tomato with the right preparation though.
Above all, have fun! While you should keep in mind your needs, make sure you choose varieties that you are attracted to- the ones that sound fun and make you excited to garden!
Which tomatoes made your garden list this year?
Do you have some old standbys or are you always trying new varieties?
And do you save your own tomato seeds?
Often my posts contain affiliate links, but this one does not. I received no compensation from any of the companies listed above. I just happen to think that they are really awesome companies that sell some pretty cool tomato seeds!
Happy tomato planting!
This Post is Featured on the Homestead Barn Hop and Green Thumb Thursday!
A great place to check out other Homesteading-related fun!
Selecting, Preparing and Canning Tomatoes
How do I? …Can Tomatoes
Quantity: An average of 23 pounds is needed per canner load of 7 quarts, or an average of 14 pounds per canner load of 9 pints. A bushel weighs 53 pounds and yields 15 to 18 quarts of juice an average of 3¼ pounds per quart.
Please read Using Pressure Canners and Using Boiling Water Canners before beginning. If this is your first time canning, it is recommended that you read Principles of Home Canning.
Procedure: Wash, remove stems, and trim off bruised or discolored portions. To prevent juice from separating, quickly cut about 1 pound of fruit into quarters and put directly into saucepan. Heat immediately to boiling while crushing. Continue to slowly add and crush freshly cut tomato quarters to the boiling mixture. Make sure the mixture boils constantly and vigorously while you add the remaining tomatoes. Simmer 5 minutes after you add all pieces. If you are not concerned about juice separation, simply slice or quarter tomatoes into a large saucepan. Crush, heat, and simmer for 5 minutes before juicing.
Press both types of heated juice through a sieve or food mill to remove skins and seeds. Add bottled lemon juice or citric acid to jars (See acidification instructions). Heat juice again to boiling. Add 1 teaspoon of salt per quart to the jars, if desired. Fill jars with hot tomato juice, leaving 1/2-inch headspace. Adjust lids and process following to the instructions in Table 1, Table 2, or Table 3 according to the method of canning used. (Acidification is still required for the pressure canning options; follow all steps in the Procedures above for any of the processing options.)
|Table 1. Recommended process time for Tomato Juice in a boiling-water canner.|
|Process Time at Altitudes of|
|Style of Pack||Jar Size||0 – 1,000 ft||1,001 – 3,000 ft||3,001 – 6,000 ft||Above 6,000 ft|
|Table 2. Recommended process time for Tomato Juice in a dial-gauge pressure canner.|
|Canner Gauge Pressure (PSI) at Altitudes of|
|Style of Pack||Jar Size||Process Time||0 – 2,000 ft||2,001 – 4,000 ft||4,001 – 6,000 ft||6,001 – 8,000 ft|
|20 min||6 lb||7 lb||8 lb||9 lb|
|Table 3. Recommended process time for Tomato Juice in a weighted-gauge pressure canner.|
|Canner Gauge Pressure (PSI) at Altitudes|
|Style of Pack||Jar Size||Process Time||0 – 1,000 ft||Above 1,000 ft|
|20 min||5 lb||10 lb|
This document was adapted from the “Complete Guide to Home Canning,” Agriculture Information Bulletin No. 539, USDA, revised 2015.
Reviewed February 2018.
Do you want to grow your own tomatoes for making sauces and salsas but you’re not sure how to pick the right variety? Technically, you can use any type of tomato to make a paste, sauce, or salsa, but the best tomatoes for canning sauces and salsas are thick walled, have few seeds, and are meatier than other tomatoes.
These denser tomatoes make your work easier as you’ll need fewer tomatoes and less time to make your sauces. Among tomato nerds like us, we call canning tomatoes with these qualities paste tomatoes.
What are paste tomatoes?
Also known as plum tomatoes, paste tomatoes have characteristics that are desirable for making sauces and salsas. These tomatoes have less juice and seeds which cuts down on processing time.
They’re also often grown on determinate, bushy plants that have high yields in a short period of time. This is desirable since you want to be able to preserve the crop in batches.
Some say paste tomatoes are mild in flavor, but this is not necessarily a bad thing. The flavor will be somewhat intensified as you condense the tomato into a sauce, and a mild tomato makes sauces that don’t overpower the flavor of the rest of your ingredients.
One variety of paste tomato that many people are familiar with is the Roma tomato. Romas are great paste tomatoes, and you’ll see lots of similar varieties of tomatoes referred to as Roma type.
Another commonly recommended paste tomato is the San Marzano. San Marzanos are praised for their flavor and texture which are ideal for homemade tomato paste, sauce, or salsa.
The problem with traditional paste tomatoes
The thing you don’t really hear talked about is that home gardeners often find that these tomatoes are hard to grow.
That’s because they’re very prone to diseases that can wipe out an entire crop which is terrible when you’re trying to grow food for your family. Paste tomatoes are also notorious for struggling with blossom end rot which makes the tomatoes unusable.
We’ve grown dozens of varieties of paste tomatoes, and we know that some plants will get blossom end rot (BER) on every single fruit. It’s incredibly frustrating!
Blossom end rot is a complex disease process that has a lot to do with how you grow your tomatoes, but some types of tomatoes are more prone to the disorder than others.
For example, elongated tomatoes with pointy ends (like San Marzano) are very prone to BER whereas cherry and heart-shaped tomatoes are very resistant.
Growing tomatoes for canning sauces and salsas
For best results growing paste tomatoes, make sure you’re burying your tomato stems as deep as possible leaving only 2-3 sets of leaves above ground. Mulch the base of your plants heavily to help block weeds and prevent moisture loss.
The way you fertilize them will affect their growth. To make healthy plants that bear lots of fruit, fertilize at planting with a nitrogen-rich fertilizer and then switch to potassium-rich fertilizer when they start making tomatoes and repeat as needed every 4-8 weeks.
It’s incredibly frustrating as a family that eats A LOT of tomatoes, that we haven’t found a really good producer in the paste tomato category.
So I went on the hunt for some paste varieties of tomatoes that are resistant to disease AND least likely to get BER. These suggestions are from seed companies and fellow tomato nerds who grow and trial many types of tomatoes to find what works the best.
Some are hybrids and some are open pollinated. If you’re not sure what that means, check out this video:
Best hybrid paste tomatoes for canning
Granadero f1 – an indeterminate variety, this hybrid has a killer disease package. It’s a heavy producer of extremely uniform medium sized tomatoes with great flavor.
Pozanno F1 – another indeterminate that has awesome resistance to diseases and not prone to blossom end rot. Has the classic San Marzano shape but doesn’t give in to long, hot summers.
Gladiator hybrid – if you’re looking for a larger paste tomato, consider growing this indeterminate variety by Burpee. This is a Roma type, but quite a bit larger and, despite its large size, is supposed to be good for patios and smaller gardens.
Best open-pollinated or heirloom paste tomatoes for sauces and salsas
Marzano fire – A striking yellow striped red tomato that has shown great resistance to disease. This variety, bred in southern California by Fred Hempel, is loved by many who grow it.
Rio Grande – bred to be tolerant of both hot and cold temperatures, this determinate plant sets lots of red, 6-8 oz tomatoes. The thick meaty tomatoes have a mild flavor but are great for canning into paste, salsa, and sauces.
Saucey tomato – An early producer of heavy yields of small red meaty tomatoes with great flavor. Fruit keeps well on the vine so you can harvest all at once.
Goldman’s Italian American tomato – very large thick walled pear-shaped tomato that is great for canning. A unique heirloom variety that has an excellent flavor for saucing.
Santa Maria – a somewhat rare indeterminate Italian heirloom paste tomato that has an excellent sweet flavor. It’s meaty and has few seeds to make canning easier.
Heidi – Excellent flavor and resistance to blossom end rot are the winning features of this tomato. Although the tomatoes are on the small side, the plant is very productive.
Oroma – A very dense, not too juicy, long holding tomato originally released by OSU. Has excellent resistance to BER despite its oblong nippled shape. I’ve heard great things about this nearly seedless paste tomato.
San Marzano Redorta – la arge Italian heirloom paste tomato with a great taste and impressive disease resistance.
Feel free to mix types of tomatoes in your sauce
One of the best things about growing your own tomatoes for canning is that you can mix in several different varieties to make your sauce. This can improve the flavor and texture of your home canned goods.
Try a few different varieties and see which ones you like the best. Then start experimenting with mixing different types of tomatoes to add sweetness, acidity, and texture.
You could also try adding some of your favorite flavored slicing tomatoes or roast some cherry tomatoes to add flavor to your sauce.
You can always freeze some tomatoes as the harvest is coming in and use them later on when you’re ready. There’s no right or wrong combination of tomatoes for making sauce, just use what you like to eat.
Have you grown paste tomatoes for sauce or salsa at home before?
Tell us about your experience in the comments below!
No store bought tomato sauce compares with the flavor of homemade. Capture summer in a jar with this seasoned tomato sauce recipe for home canning.
I talk about canning tomato sauce a lot here at Grow a Good Life, especially this year as I faced the challenge of preserving a bumper crop. It seems I constantly had baskets of ripe tomatoes to work through for the last two months. Now that the last tomato harvest is simmering on the stove, I thought it was time to share the tomato sauce recipe and method I use to preserve the majority of my homegrown tomato harvest.
Growing up in an Italian household, the only tomato sauce we were aware of was the homemade kind made from tinned or fresh tomatoes in season. There were no jars of purchased tomato sauce in our pantry. As an adult, I continued the tradition cooking up large batches of homemade tomato sauce and freezing it for future meals.
When I began growing a garden of my own, one of the first things I learned to can was tomato sauce from homegrown tomatoes. Eventually, I made it my yearly goal to grow enough tomatoes to provide a sufficient amount of canned tomato sauce to last us until the following season.
Tips for Canning Tomato Sauce
Follow a Safe Canning Recipe: If you are canning tomato sauce, is important to use recipes that are formulated and tested for safe home canning. When I make tomato sauce for canning, I follow the tomato sauce recipe in the Ball Blue Book Guide to Preserving for “Seasoned Tomato Sauce.” This is the closest to the homemade tomato sauce I grew up with.
The only differences between the recipe below and the Ball Seasoned Tomato Sauce is this recipe is cut in half. The ratio of ingredients is the same. I just find working with 22.5 pounds of tomatoes is much easier to manage since I only have two large pots to cook down the sauce.
I also reduce the sauce by slow cooking it over low heat for a longer period to preserve flavor rather than cooling over medium-high heat as indicated in the Ball recipe. Sometimes this takes all day, but the flavor is worth the effort.
Prevent Botulinum: When canning tomatoes, an acid must be added to your jars before filling to prevent the growth of C. Botulinum bacteria, which causes botulism. I’ve used bottled lemon juice in the past, but now find it easier to use Citric acid. Citric acid also doesn’t change the flavor like lemon juice can.
Select meaty, plum type tomatoes for a thick and flavorful sauce. My favorites are Amish Paste, Juliet, Roma, and San Marzano. Paste tomatoes are meaty with thick walls and have very little water content. You can still use other types of tomatoes, but it will take longer for the extra water to cook out.
Initially cooking your tomatoes with the skins and seeds aids in extracting the natural pectin that will help thicken the sauce. After the tomatoes have softened, I run them though a through a food strainer or food mill to remove skins, seeds, and to smooth out the sauce. Then return the pots to the stove, add the remaining ingredients, and simmer on low heat until the sauce is reduced by half.
The way I do the initial cooking depends on the temperature. If it is hot outside, I fill my largest pots with sliced tomatoes and cook them on the stovetop until they soften and reduce their juices. If the weather is cooler, I turn on my oven I fill my roasting pans with sliced tomatoes and roast them in the 325°F/ 177°C oven for about an hour or until they are soft. Roasting helps to reduce the extra moisture and adds a lovely, deep tomato flavor to the finished sauce.
- Water Bath Canner
- 8 pint jars or 5 quart jars
- Lids and bands
- Food strainer or food mill, or sieve
- Lids and bands
- Canning tools: lid lifter, jar lifter, canning ladle, funnel, and bubble popper
Plus basic kitchen supplies such as a large sauce pot, large bowl, small pot, towels, knife, large spoon, potato masher, and a cutting board.
Prepare your tomatoes by washing in plain water. Cut them in half or quarters and add to your sauce pots.
Sauté the onions and garlic in olive oil until soft, then add to the saucepans.
Remove skins and seeds. As the tomatoes simmer, they will release their juices. After the tomatoes and the vegetables are soft, turn off the heat and allow the sauce to cool. Run the cooled tomato sauce through a food strainer or food mill to remove skins, seeds, and to smooth out the sauce. Return the sauce to the stove, add the remaining ingredients, and simmer until the sauce is thickened.
5 from 11 votesSeasoned Tomato Sauce Recipe Select meaty, plum type tomatoes for a thick and flavorful sauce. My favorites are Amish Paste, Juliet, Roma, and San Marzano. Paste tomatoes are meaty with thick walls and have very little water content. You can still use other types of tomatoes, but it will take longer for the extra water to cook out. Course: Canning Author: Grow a Good Life Ingredients
- 22.5 pounds paste tomatoes
- 3 cups chopped onions about 3 large onions
- 6 cloves garlic minced
- 1/4 cup extra virgin olive oil
- 1 tablespoon dried oregano
- 3 dried bay leaf
- 1/2 tablespoon ground black pepper
- 4 1/2 teaspoons cane sugar
- 1 teaspoons red pepper flakes optional
- citric acid or bottled lemon juice
- 1 teaspoon kosher salt or more to taste
- Prepare your tomatoes by washing in plain water. Cut them in half or quarters and add to your saucepots.
- In a large frying pan, sauté onions and garlic in olive oil until soft. Add to the saucepans with the prepared tomatoes. Simmer on low heat, stirring occasionally so to prevent sticking.
- As the tomatoes simmer, they will release their juices. After the tomatoes and the vegetables are soft, turn off the heat and allow the sauce to cool.
- Run the cooled tomato sauce through Food Strainer or Food Mill to remove skins, seeds, and to smooth out the sauce.
- Return the strained tomato sauce to the saucepan(s) to cook down further to thicken the sauce. Add oregano, bay leaves, pepper, sugar, and crushed red pepper. If you are using multiple pots, roughly divide the ingredients for each pot. All the ingredients will be combined into one pot as the sauce cooks down. Simmer over low heat with the cover vented so the excess moisture evaporates. As the sauce reduces, combine it into one pot. Use your ladle to avoid splashing.
- Once the volume is reduced by half, your tomato sauce should be nice and thick. Use a clean spoon and taste the sauce. Add salt and stir in. Taste again. Add more salt if needed. Keep the sauce warm over low heat.
- Prepare your jars and lids by washing in warm, soapy water and rinsing thoroughly. Place jar rack into water bath canner, set jars in the canner, add water, and boil jars for 10 minutes to sterilize. Warm your lids in a small pot over low heat. Keep jars and lids warm until ready to use.
- Spread a kitchen towel on the counter. Use your jar lifter to remove warm jars from canner, drain, and line up on the towel. Add citric acid or bottled lemon juice to each jar. For pints, add 1/4 teaspoon of citric acid or 1 Tablespoon of bottled lemon juice to each jar. For quarts, add 1/2 teaspoon citric acid or 2 Tablespoons of bottled lemon juice to each jar.
- Use your canning ladle and funnel and add tomato sauce to warm jars leaving 1/2-inch headspace. Wipe the rims. Use your magnetic lid lifter to lift lids out of the warm water, center lid on the jar, and screw on band until it is fingertip tight.
- Using a jar lifter, place jars carefully into canner leaving space in between them. Once jars are all in canner, adjust the water level so it is at least one inch above the jar tops. Add more boiling water if needed so the water level is at least one inch above the jar tops. When adding water, use the hot water from the small pot your lids were in. Pour the water around the jars and not directly onto them.
- Cover the canner and bring to boil over high heat. Once water boils vigorously, process pints for 35 minutes and quarts for 40 minutes at altitudes of less than 1,000 ft. (adjust processing time for your altitude if necessary).
- When processing time is complete, turn off heat and allow the canner to cool down and settle for about 10 minutes. Spread a kitchen towel on the counter; remove the cover by tilting lid away from you so that steam does not burn your face. Use a jar lifter to lift jars carefully from canner and place on the towel. Allow the jars to cool for 12 to 24-hours. You should hear the satisfactory “ping” of the jar lids sealing.
- After 12 to 24-hours, check to be sure jar lids have sealed by pushing on the center of the lid. The lid should not pop up. If the lid flexes up and down, it did not seal. Refrigerate jar and use up within a few days.
- Remove the screw on bands and wash the jars. Label and date the jars. Store your jars in a cool, dark place and use within 12 months. Yields about 6-7 pint jars or 3-4 quarts depending on how much the sauce reduces.
Additional Canning Information:
USDA Complete Guide to Home Canning
How to Can: Getting Started at the Ball Website
6 Tips to Prepare for Canning Season
You May Also Like:
- Crockpot Tomato Sauce
- Homemade Applesauce for Canning
- Honey Sweetened Concord Grape Jelly
- Granny’s Bread and Butter Pickles
- Fresh Summer Tomato Sauce
Every Italian girl should can tomatoes at least once in her life to appreciate the soul and love that goes into making exceptional Marinara sauce. Well, OK, you don’t have to be Italian to love canning tomatoes. For me, it feels primal to harvest and put up a bushel of tomatoes for the winter. I feel like I have accomplished something special, and just love looking at the bright red jars in my pantry. I also love good imported canned San Marzano tomatoes (see my Marinara sauce recipe) but having my own canned local, organic tomatoes is very satisfying as well. At first it seems like a big deal but once you do it and realize how simple it is, you will look forward to harvest time every year with a smile.
The best tomatoes for canning are Roma tomatoes. They are more dense and less watery which produces a thicker and meatier sauce. However I used organic Beefsteak tomatoes from our local CSA (Community-Supported Agriculture), Sandhilll Family Farms. I had the pleasure of trying them recently at a Farm to Table dinner, and was captivated on how rich and sweet they were. Since the Beefsteak tomatoes were at their peak, I bought 40 pounds. I canned 30 pounds and used the rest for tomato jam, Caprese Salad, and BLTs. Please support your local CSA for the freshest, healthiest local produce you can get. Plus I like supporting local businesses!
Crushed tomatoes are ideal for sauce, soup and stew recipes. Crushing them also makes it easier to strain out some of the watery juice while canning, which I needed to do with the Beefsteak variety. The meat and flavor of the Beefsteaks were incredible.
Since food safety is very important with preserving and canning, I used the classic canning recipe from the Ball Jar Company, the maker of the canning jars. You can read more about canning at their website.
The following is a step-by-step look at the process. The printed recipe can be found at the end.
Wash tomatoes and cut a large cross on the bottom of each tomato.
The skin will easily slip off.
Core the tomatoes and cut in quarters.
Cook in large enameled pot, gently crushing the tomatoes as they cook down.
Fill quart-sized jars with crushed tomatoes and 2 tablespoons of lemon juice to increase acidity.
Place the sealed jars in boiling water in a large canning pot. Be sure to place them in a wire rack or on a towel to keep the jars off the bottom. Simmer for 45 minutes to achieve a good solid seal.
Tomato Harvest: Canning Beefsteak Tomatoes
Canning tomatoes is easier than is seems. Follow the classic recipe at Ball Jar to ensure your food is safe to eat after prolonged storage. Course Canning Servings 8 quarts Author Homemade Italian Cooking with Cara
- 25 – 30 lbs tomatoes
- ½ tsp Ball® Citric Acid or 2 Tbsp bottled lemon juice to each hot quart jar or ¼ tsp Ball® Citric Acid or 1 Tbsp bottled lemon juice to each hot pint jar
- Salt 1 tsp salt to each quart jar or 1/2 tsp salt to each pint jar (if desired)
- Ball® Glass preserving jars with lids and bands
- PREPARE boiling water canner. Heat jars in simmering water until ready for use. Do not boil. Wash lids in warm soapy water and set bands aside.
- WASH tomatoes. Dip in boiling water 30 to 60 seconds. Immediately dip in cold water. Slip off skins. Trim away any green areas and cut out core. Leave tomatoes whole or cut into halves or quarters.
- CUT tomatoes into quarters to measure about 2 cups. Transfer to a large stainless steel saucepan and bring to a boil over medium-high heat. Using a potato masher, crush tomatoes to release juices. While maintaining a gentle boil and stirring to prevent scorching, quarter additional tomatoes and add to the saucepan as you work. The remaining tomatoes do not need to be crushed, as they will soften with heating and stirring. Continue until all tomatoes are added, then boil gently for 5 minutes.
- ADD ½ tsp Ball® Citric Acid or 2 Tbsp bottled lemon juice to each hot quart jar. Add ¼ tsp Ball® Citric Acid or 1 Tbsp bottled lemon juice to each hot pint jar. I used lemon juice.
- PACK hot tomatoes into hot jars to within a generous 1/2 inch of top of jar. Press tomatoes into the jar until the spaces between them fill with juice, leaving 1/2 inch headspace. Add 1 teaspoon salt to each quart jar, 1/2 teaspoon to each pint jar, if desired. Remove air bubbles and adjust headspace, if necessary, by adding hot tomatoes. Wipe rim. Center hot lid on jar. Apply band and adjust until fit is fingertip tight.
- PROCESS filled jars in a boiling water canner for 35 minutes for pints and 45 minutes for quarts, adjusting for altitude. Remove jars and cool. Check lids for seal after 24 hours. Lid should not flex up and down when center is pressed.
The Influence of Different Tomato Varieties on Acidity as It Relates to Home Canning
The canning of home grown produce has been popular for many years. Tomatoes are the most widely canned product in the United States and also one of the most commonly spoiled products. It is generally accepted that “low acid” products, such as green beans, for example, should be processed in a pressure canner to insure safety from micro-organisms. Other produce, such as peaches and tomatoes, are considered “high acid” and need only be processed in a water bath canner. Tomatoes are considered high acid as long as the pH is below 4.6.
There has been speculation that certain growing conditions and possibly varieties may cause tomato products to have lower acidity than is safe for canning. When this happens, the product must be canned in a pressure canner, as low acid products, or acidified to a pH of 4.6 or lower with lemon juice or citric acid (Kendall, 2006). In a study of 162 home canned tomato products collected in Washington, 6% of the samples collected had a pH value over 4.6, and 3% of those showed visible mold growth (Drake & Price, 1981). Mold growth lowers acidity, allowing botulism to grow which produces a deadly toxin.
Because home growers in general do not know the specific pH of the tomatoes they are growing, it is recommended that they add an acidifying agent such as vinegar, lemon juice, or ascorbic acid to increase the acidity. Acidification guidelines given by the USDA (Complete Guide to Home Canning, 1994), reference the use of bottled lemon juice or citric acid to ensure safe acidity in whole, crushed, or juiced tomatoes. A survey conducted by Oregon State University Extension (Raab, 1990) showed that 26% of participants did not add any citric acid or lemon juice as instructed to acidify their tomato products. This particular survey shows that one fourth of those surveyed were either skeptical that acidification wasn’t needed or were reluctant to add it.
Cooperative Extension Services receive numerous questions each year regarding how to safely can tomatoes and other produce. They have been including in their recommendations for many years that tomatoes selected for canning should not be overripe, bruised, or damaged. Caution has also been given not to use tomatoes from vines damaged by frost, insects, or blossom end rot (Kendall, 2006). Anything that can affect fruit quality or the plant’s ability to allow tomatoes to ripen properly may lower acidity. An aspect that has not been well documented is the influence of different tomato varieties on acidity. For example, is a Celebrity tomato less acidic than an older heirloom variety such as Brandywine? Some gardeners have expressed the feeling that older varieties are, in general, more acidic than newer varieties.
In a bulletin from the North Dakota Extension Service regarding the use of lemon juice in canned tomatoes and salsa (Garden-Robinson, Houge, & Smith, 2004), the pH of 15 different tomato varieties were tested. The pH readings were taken from the pure tomato pulp prior to canning and again after lemon juice was added and the tomatoes were made into salsa. In this particular study, all of the raw tomatoes tested had a pH from 4.8 to 5.2 prior to canning. In other words, the acidity was so low that all required that lemon juice be added before they could be processed safely. Lemon juice increased acidity in all samples enough to allow processing without using a pressure canner.
In 2007, we grew and tested the pH of five different tomato varieties (Table 1). We collected enough tomatoes to process all of one variety in each jar. We took a second jar and added lemon juice as per USDA instructions. In each case the pH was lowered by adding lemon juice. The average pH change due to lemon juice being added was .35 over the five varieties. This is consistent with the North Dakota study.
|Variety||Tomato pH||pH of Tomato + Lemon|
In 2008, we conducted an additional study to determine the acidity of different tomato varieties without the use of lemon juice. Tomato varieties selected for the study included Row Pack, Celebrity, Rutgers, Ace, San Marzano, Box Car Willie, Brandywine, Goliath, Legend, Roma, and an unknown variety from a local grocery store. We included in our selection hybrids, heirlooms, and open pollinated varieties. Celebrity is a popular variety among home growers and was our choice to represent the hybrid category when it comes to comparing pH.
When harvested, tomatoes were sorted into “under ripe,” “ripe,” and “over ripe” categories, based on their appearance. Under ripe tomatoes were harvested mostly red while a slight green color remained. Ripe tomatoes were firm, with no green color present. The over ripe tomatoes were allowed to sit for a couple days after reaching the ripe stage. We did this with the understanding that stage of ripening may affect tomato pH as well as variety. Some varieties had few fruit ripening at the same time so we did not have many tomatoes to place into all categories.
All samples were analyzed with an Omega hand-held pH tester model 5012. The meter was calibrated using a buffer solution prior to use (each time). Juice was extracted from each tomato and tested separately. The meter was inserted into the juice and then stirred gently before taking a reading (Table 2).
|Variety||Under Ripe||Ripe||Over Ripe|
|Box Car Willie||3.95||4.07||4.13|
|Each value represents the average pH of three tomatoes.|
The statistical analysis program known as “SAS” was used to compare the pH of different tomato varieties. From the 10 varieties grown, enough data was collected to run comparative statistics on five of them. The three heirloom varieties, “Ace,” “Box Car Willie,” and “Rutgers,” were compared to the hybrid variety “Celebrity.” The pH of the heirloom varieties was different from that of the hybrid variety at the 95% confidential level. So within the varieties that we chose, the heirloom tomatoes had a higher pH (so they were less acidic) than the hybrid variety. The open pollinated variety “Row Pack” was not significantly different from either the heirloom or hybrid varieties.
When the pH of the different varieties was compared, on the basis of maturity, we did not see any differences. Although slight differences were observed, in the color of the fruit as well as the pH readings, they did not prove to be significantly different.
|Type||Avg. Ripe pH||Type||Avg. Ripe pH||Type||Avg. Ripe pH|
|Box Car Willie||4.07|
In theory, it is safe to use a water bath canner without adding acidifying agents as long as the pH is less than 4.6. In our study, all varieties had an acceptable pH for canning (3.92-4.36) prior to adding and acidifying agents. Statistically the heirloom varieties had less acidity than the hybrid variety Celebrity. So, in our study the notion that “heirlooms” are more acid than “hybrids” did not hold true.
However, in application, a person is not likely to know the exact pH of each tomato being canned. Nor is it practical to test each jar before it is processed. Home canning often consists of harvesting more than one tomato variety from the garden and processing them together, sometimes adding a mixture of other items such as peppers, spices, etc. Based on this and our findings, we suggest that the USDA recommendations be followed, that all tomatoes and tomato products be properly acidified prior to canning, regardless of the varieties used. We also feel that, although differences in pH due to variety may exist, the study reported here should not be relied upon as the factor to determine whether to add an acidifying agent or not.
Extension agents are educators by profession. Their mission is to teach “research based” methods to the public. For various reasons, rumors or opinions are spread around as though they are truth, such as the notion that “older tomato varieties are more acidic than newer hybrids” and therefore safe to can without acidifying agents. In our study, the tendency was for the older varieties to be less acidic than the hybrid we compared them to. Advice is sought from Extension agents each season regarding which tomato varieties to grow successfully and how to safely process them. We feel that it is important for Extension agents to promote the current USDA recommendations and to understand them well enough to advise others. Using correct methods to process tomatoes for home storage will ensure a safe product. Selecting which tomato variety is used may help control acidity, but it is hard to know how much other local factors such as weather and soil conditions may contribute.
United States Dept of Agriculture. Selecting, preparing and canning tomatoes and tomato products. Complete guide to home canning guide 3. Retrieved December 16, 2008 from: http://uga.edu/nchfp/publications/usda/utah_can_guide_03.pdf
Heirloom Tomatoes. Image credit: wunee / morguefile.com.
You may see the need for acidification of water-bathed (or steam canned) tomato products being credited to “new varieties” of tomatoes. These new varieties, the explanation continues, don’t have the same acidity level as the old, “heirloom” (aka vintage or heritage) tomatoes of days gone by.
On a good day, today’s dirt even gets blamed as not being as good as yesterday’s dirt:
Back in my grandmother’s and mother’s day, you could can tomatoes without lemon juice because it was acidic enough. Today all the recipes say you’ve got to add lemon juice to be sure it’s acidic enough to be safe. Why? Today’s soils have changed…..” Gibbons, Kathy. Yes, you can! Traverse City, MI: Record-Eagle. 16 November 2015.
This has created some confusion, given that this is being said at a time when “heirloom variety” tomatoes are flooding back on the market. Some people are understandably, though mistakenly, concluding that therefore the older, heirloom varieties must be safe without acidification.
For various reasons, rumors or opinions are spread around as though they are truth, such as the notion that ‘older tomato varieties are more acidic than newer hybrids
Research disproves the myth of older tomatoes being more acidic
For various reasons, rumors or opinions are spread around as though they are truth, such as the notion that ‘older tomato varieties are more acidic than newer hybrids’. In fact, though, it turns out that actual research into the question has shown the opposite: that many heirloom varieties are lower acid than modern ones.
Three separate studies were done, at the University of Wisconsin, at North Dakota State, and at Utah State. University of Minnesota Extension. New and Old Tomatoes Need Acid and Heirloom Tomatoes. In: Home Food Preservation Newsletter, August 2012. Accessed March 2015 at https://www.extension.umn.edu/food/food-safety/home-food-preservation-newsletter/docs/home-preservation-august-2012.pdf. All three universities showed the same results: many heirloom tomatoes were in fact less acidic than modern varieties.
The University of Wisconsin Extension tested the pH of 55 heirloom tomato cultivars. When they grew the plants for testing, the growing season that year was warm early, then cool and wet.
27% of the heirloom tomatoes had a mature pH of 4.6 or higher including Brandywine, Ace, Big Early Hybrid, and Big Girl.
The Extension also reported other factors they found that lowered the acidity:
In addition to the raw tomato fruit, several other factors influence the safety and acidity of canned tomato products:
- Tomato juices are less acidic than tomato solids
- One or more over-ripe tomatoes in a jar will decrease the overall acidity
- Adding low-acid ingredients- onions, celery, garlic, peppers- will decrease the acidity
- Canning itself can decrease acidity
Small-fruited cultivars and white, yellow and pink tomatoes are in the same acidity range as most standard red tomatoes. The difference in taste of these ‘low acid’ tomatoes is due to higher sugar content which masks acid flavor. Paste tomatoes are, however, consistently LOWER IN ACID (higher in pH) than standard tomatoes. So add acid, regardless of color.” Canning Tomatoes & Tomato Products. Powerpoint Presentation. Lunch & Learn, 23 July 2012. Slide 4 notes. University of Wisconsin Extension. Accessed March 2015.
The variety of tomato you are canning doesn’t matter. Just use the recommended processes; they will give you a safe product regardless of the variety (or the growing conditions that particular season).
Gerald Kuhn, team leader of the first modern USDA Complete Guide, and Elizabeth Andress, head of the National Center for Home Food Preservation, reviewed some of the early findings from the 1970s and 1980s, and looked at how early researchers dealt with the issue of the lower acidity in older tomato varieties:
Ripeness, decay and bruising result in elevated pH values above a safe level, but cultivar alone was found to offer a minimal risk (Sapers et al, 1978). Therefore, home canners were advised not to be too concerned by tomato varieties, but rather to select only top quality tomatoes and to use recommended processes.” Andress, Elizabeth L and Gerald Kuhn. Chapter III, G. Tomatoes. In: Critical Review of Home Preservation Literature and Current Research. Athens, GA: University of Georgia, Cooperative Extension Service. 1998.
Here’s a chart from North Dakota state showing that the pH of mixed modern and heirloom tomatoes is all over the map, and often way above the safety cut-off of 4.6:
Diane Wright-Hirst from the University of Connecticut writes,
The pH of tomato varieties can range from an acidic low of 3.8 to a much less acidic pH of 4.7. The story goes that as the consumer has demanded a less acidic tomato, hybrids have been developed that taste less acidic—but some argue that this is due to more sugar in the tomato, not less acid. Would that mean that older heirloom varieties are likely to be more acidic? Not necessarily.
A study by Heflebower and Washburn at Utah State in 2010 looked at hybrid varieties, open pollinated and heirloom varieties. The results indicated that the average pH was 3.92 for the hybrids they tested, 4.03 for open pollinated and 4.16 for the heirloom. Of course all of these are below the 4.6 borderline. The authors still recommend the addition of acid to ensure that the final product remains below 4.6.
In a bulletin from the North Dakota Extension Service regarding the use of lemon juice in canned tomatoes and salsa (Garden-Robinson, Houge, & Smith, 2004), the pH of 15 different tomato varieties were tested. The pH readings were taken from the pure tomato pulp prior to canning and again after lemon juice was added and the tomatoes were made into salsa. In this particular study, all of the raw tomatoes tested had a pH from 4.8 to 5.2 prior to canning.
In your home garden, a number of factors can influence the pH of even the more acidic tomatoes: these include soil, vine health, ripeness.” Wright Hirsch, Diane. Canning Tomatoes: There is a Right Way. University of Connecticut Extension. 1 September 2014. Accessed March 2015.
So, in summary, it was just that the understanding of the science had been wrong: tomatoes, old or new varieties, are just not reliably always on the low side of the 4.6 safety divide.
Utah State conducted a similar study in 2007 and 2008 and also found that many heirloom varieties were likely to be less acidic than modern varieties.
For various reasons, rumors or opinions are spread around as though they are truth, such as the notion that ‘older tomato varieties are more acidic than newer hybrids’ and therefore safe to can without acidifying agents. In our study, the tendency was for the older varieties to be less acidic than the hybrid we compared them to.” Heflebower, Rick and Carolyn Washburn. The Influence of Different Tomato Varieties on Acidity as It Relates to Home Canning. Utah State University Extension. Volume 48, # 6. December 2010
Consequently, whether jars of tomatoes are being water bathed or pressured canned, whether they are a prized heirloom variety or this year’s latest hybrid, they must have acidity added to them by the person doing the canning. (See here for more information on why some pressure canned tomato products have to be acidified.)
Bonnie Henderson / morguefile.com
Why does the myth still persist despite all the research?
Why do some home canning teachers still promulgate the myth, then?
Scientists suggest it is because many are educators, not scientists, and they haven’t been made aware yet of current research:
Extension agents are educators by profession. Their mission is to teach “research based” methods to the public. For various reasons, rumors or opinions are spread around as though they are truth, such as the notion that “older tomato varieties are more acidic than newer hybrids” and therefore safe to can without acidifying agents…..
We feel that it is important for Extension agents to promote the current USDA recommendations and to understand them well enough to advise others.” Heflebower, Rick and Carylyn Washburn. The Influence of Different Tomato Varieties on Acidity as It Relates to Home Canning. Journal of Extension. December 2010. Volume 48 Number 6. Article Number 6RIB6
Green heirloom tomatoes
Green Zebra Tomatoes ripen to green. Pattie / flickr.com / 2008 / CC BY-SA 2.0
When a home canning recipe calls for green tomatoes, it means unripe tomatoes.
It does not mean a heritage variety of tomato such as German Green or Green Zebra which ripen to green.
The recipe creators are after a tomato that is still green because it is unripe, and thus has a higher acidity range than ripe tomatoes.
A recipe calling for green tomatoes will be looking for that acidity range for safety which a “naturally green when fully ripe” tomato may not have.
(Tomatillos can always be substituted safety-wise for green tomatoes, as they are more acidic even yet, though tomatillos must still be acidified if canned on their own. Whether you would want their extra sour taste in your chow chow is another issue.)
An unsettling conclusion about tomato-canning history
To recap the story so far:
- older tomato varieties were if anything prone to be less acidic than modern varieties;
- people were canning those tomatoes without any added acidification.
To make it worse, a woefully inadequate recommended processing time of just 10 minutes per quart (see table below) for crushed tomato floated around in old, cherished canning guides until the USDA Complete came out in 1988 and corrected it to the 45 minutes that is is today.
Bureau of Human Nutrition and Home Economics. Home Canning of Fruits and Vegetables – AWI 93. Washington: USDA. May 1944. Page 13. DO NOT USE.
So even if the “heirloom tomatoes” had by chance been acidic enough to start with in the jar, moulds seen and unseen could have survived the short 10 minute processing, causing that acidity to be lowered, and thus allowing any botulism spores present to spring to life, germinate and produce their deadly toxin in doing so.
The chances of illness would have been far higher than today. How many families got “gippy tummies” or worse? The capacity or desire for data collection on population health just wasn’t there in the first half of the 1900s, so incidents weren’t tracked and analysed the way they are now.
Still, in the 1950s, questions about the acidity of tomatoes for home canning were already being raised.
In the mid-1950s, the acidity level of tomatoes became a real concern as related to processing recommendations.” Andress, Elizabeth L and Gerald Kuhn. Chapter III, G. Tomatoes. In: Critical Review of Home Preservation Literature and Current Research. Athens, GA: University of Georgia, Cooperative Extension Service. 1998.
Resources for studies weren’t available until the 1970s, but they confirmed the worries from the 1950s: that many of the tomato varieties were low-acid, and that the acidity of “higher acid” ones could see-saw back and forth across the safe line. (See: Evolution of the understanding of tomatoes as borderline acidic.)
To confirm, the study looked at what we now call “heirloom” tomatoes. Today’s modern tomato varieties were still under development at that time in seed growers’ green houses: they weren’t even released yet.
The lucky people would have been those whose jars spoiled with visible signs of spoilage, so they could be disposed of. The unlucky people would have had the silent, deadly, invisible type of spoilage lurking in their pantry.
In saying that in the “old days” people had it easier because of the acidity of heirloom tomatoes is actually masking the horrible truth. They had it harder because the varieties if anything would have often been less acidic, there was no acidification procedure for them to draw on, and, the processing times would have resulted in home canned tomato products that were woefully underprocessed.
To be clear, this is not to say the opposite — that because many of today’s varieties are more acidic you don’t have to acidify.
The takeaway instead is: the acidity of tomatoes will always be all over the map, even with the same variety, just based on growing conditions and year alone. Heirloom varieties were and are no magic bullet, nor are modern for that matter. A tart or sweet taste is no indication of the right or wrong pH.
You want a pH of 4.6 or less in that jar. The only way to ensure that kind of safe product for your friends and family is to properly acidify that jar of tomatoes.
Browse site on all tomato canning topics
|1.||Gibbons, Kathy. Yes, you can! Traverse City, MI: Record-Eagle. 16 November 2015.|
|2.||University of Minnesota Extension. New and Old Tomatoes Need Acid and Heirloom Tomatoes. In: Home Food Preservation Newsletter, August 2012. Accessed March 2015 at https://www.extension.umn.edu/food/food-safety/home-food-preservation-newsletter/docs/home-preservation-august-2012.pdf.|
|3.||Canning Tomatoes & Tomato Products. Powerpoint Presentation. Lunch & Learn, 23 July 2012. Slide 4 notes. University of Wisconsin Extension. Accessed March 2015.|
|4.||Andress, Elizabeth L and Gerald Kuhn. Chapter III, G. Tomatoes. In: Critical Review of Home Preservation Literature and Current Research. Athens, GA: University of Georgia, Cooperative Extension Service. 1998.|
|5.||Wright Hirsch, Diane. Canning Tomatoes: There is a Right Way. University of Connecticut Extension. 1 September 2014. Accessed March 2015.|
|6.||Heflebower, Rick and Carolyn Washburn. The Influence of Different Tomato Varieties on Acidity as It Relates to Home Canning. Utah State University Extension. Volume 48, # 6. December 2010|
|7.||Heflebower, Rick and Carylyn Washburn. The Influence of Different Tomato Varieties on Acidity as It Relates to Home Canning. Journal of Extension. December 2010. Volume 48 Number 6. Article Number 6RIB6|
|8.||Andress, Elizabeth L and Gerald Kuhn. Chapter III, G. Tomatoes. In: Critical Review of Home Preservation Literature and Current Research. Athens, GA: University of Georgia, Cooperative Extension Service. 1998.|