As far back as I can remember, my mother made it a point to pick or buy enough tomatoes to can a dozen quarts for my older sister, who liked to have them on hand for making stews, soups, and sauces during the winter months. As a result, every time I see a tomato field, I feel the urge to stop and pick a bushel or two and can them for my sister even though she doesn’t cook much anymore. Old habits die hard!
So how do you can tomatoes? Here is how my mother did it by using the boiling water bath method.
1. Pick or Buy the Tomatoes
The best way is to either grow your own or find a farmer who has a field of pick-your-own tomatoes and carefully select a bushel of the most perfect, unblemished tomatoes you can find. If neither of these options are available to you, you can buy them by the bushel at roadside stands or your local Farmers’ Market.
If you are not sure where your closest Farmers’ Market is, the USDA has a free locator on their website. I included a link to it below.
Tomatoes ripen pretty fast, so choose tomatoes that are in two or three stages of ripeness unless you plan to can them all in one day. My family likes to “put up” or can a dishpan full every day by selecting various stages of ripeness, spreading them out on newspaper on a large table or the floor, and canning a few jars every day until they are gone.
How Many Tomatoes Do I Need For Canning?
The number of tomatoes you need for canning depends on the size of the tomatoes and how many jars you would like to can. You can use as a rule of thumb that it will take 3 lbs of fresh tomatoes to produce 1 quart of canned tomatoes or 1.5 lbs of fresh tomatoes to make 1 pint of canned tomatoes.
2. Gather All Supplies, Equipment, and Utensils
As with any process, you will need to gather the needed supplies, utensils, and equipment needed.
To make sure you have everything, it is listed in my resource: How to Do Water Bath Canning | What I Learned Over 50 Years
If you are new to this, the number of tools might seem daunting. The good news is that you probably have a lot of what you need already in your kitchen. And, once you have everything you need, you don’t need to buy any more tools. The same basic tools are used no matter what you are canning.
Pro Tip: Once you gather your tools the first time, just store them away in the same container and pull them out each time you do some canning.
3. Check Jars and Wash Jars, Lids, and Rings
Check your jars for any nicks, cracks, or rough edges around the rim that could cause them to break, discarding any with imperfections. Then wash jars, lids, and rings in hot soapy water and rinse thoroughly until they are immaculate with no soap residue.
4. Add Water to Canner and Bring to A Boil
Fill the canner approximately ½ full of water and bring to a boil over high heat. Make sure there is enough water in the canning pot to cover the jars with at least 1 inch above the tops of the jars. Then, reduce heat and keep the water simmering while preparing your food for the boiling water bath.
5. Sterilize Jars
There are several ways to sterilize your canning jars. Most dishwashers have a sanitize setting, and some people sanitize their jars in the oven by placing them on a baking sheet and putting them in a 220-degree oven for at least 10 minutes. However, according to the National Center for Home Food Preservation, it is not necessary to pre-sterilize the jars if they are processed in the boiling water bath for at least 10 minutes. However, I recommend always pre-sterilizing the jars before filling by following this method:
After checking your jars for damage and washing the jars, lids, and rings, place the clean jars in a pan or pot with enough water to allow them to sit in about one inch of water. Bring them to a full rolling boil, allowing them to boil for at least 10 minutes to sterilize them while cooking the food.
6. Prepare Lids
Add enough water to a saucepan or baking pan to cover the lids you need, and bring to a full rolling boil. Then, reduce the heat and add the clean lids to the water, allowing them to sit in the water at a simmer until needed.
7. Prepare and cook the tomatoes and fill jars
Prepare the food that you are canning. Start by choosing a pan of the ripest tomatoes, washing them well, and peeling them by using this method:
- Drop tomatoes into boiling water and let stand for 30 to 60 seconds.
- Remove them from the boiling water and quickly drop them into a pan of cold water.
- At this point, the skins should slide right off.
- Trim away any green areas and blemishes and cut out the core.
- Cut tomatoes into quarters or crush them by hand, if desired.
- Transfer to a large stainless steel saucepan and bring to a boil over medium-high heat. (It isn’t necessary to add water.)
- Using a potato masher, crush tomatoes to release juices.
- Boil gently for 5 minutes.
- While tomatoes are cooking, add salt and lemon juice or citric acid to each jar.
- Fill the jars one at the time while they are still sitting in boiling water.
- With a clean, damp cloth, wipe the jar rims to ensure there is no residue that would prevent the lids from sealing.
- Add the hot lids and rings, tightening snugly, but do not overtighten.
8. Process tomatoes in boiling water bath
- Place jars in the boiling water bath canner, making sure the water covers all the jars by at least 1 inch.
- Turn the heat to high and bring the water in the canner back to a full rolling boil.
- When the water has reached the boiling point, set your timer, cover, and process the filled jars for 35 minutes for pints and 45 minutes for quarts.
- If the water stops boiling during the processing time, bring the water back to a full rolling boil and start the process again, setting your timer back to the original process time.
9. Remove Jars From Canner and Cool
- When jars have been processed for the required time, turn off the heat and lift the rack to the rim of the canner.
- Remove the jars from the canner.
- Dry the jars and place them in a previously prepared spot to sit undisturbed for at least 24 hours. Spread the jars out, so they are at least an inch apart and have room to cool. Do not retighten the bands as this may affect the sealing process, and do not press on the center of the lid.
10. Inspect Lids for a Good Seal and Store Properly
- When the jars of tomatoes have completely cooled, inspect the lids to ensure they have sealed. The center of the lid should not flex when the center is pressed. If a lid fails to seal within 24 hours, immediately refrigerate the product.
- Clean the jars and the lids with warm soapy water to remove any residue from the canning process and dry.
- Label each jar with the contents and date.
- Store in a cool, dry, dark place for up to 1-½ to 2 years. Check lids from time to time to be sure they have maintained a good seal.
How to Store Homemade Canned Food
To maintain the best quality for the maximum length of storage time, all homemade canned food that has been processed by using approved canning methods should be stored under the following conditions:
- In a cool space in which the temperature should remain between 50 and 70 degrees Fahrenheit with no significant temperature changes.
- In a dark space that is never exposed to direct or indirect sunlight or bright light of any kind.
- In a pantry or storage area that is dry and as free from high humidity as possible.
If your canned foods are made and stored by the guidelines mentioned above, most sources recommend that they are used within one year for optimum quality and taste. However, they should be good for much longer so long as the seal is intact. There may be some discoloration and changes in consistency over time, but as long as the lids are sealed, and they taste good, they should remain safe to eat.
But let me add, if you have any doubts about whether the contents of a home-canned jar are still good, err on the side of caution, and discard the contents. However, you should keep the jar since they can be reused many times unless they become cracked, chipped, or otherwise damaged.
Can Tomatoes Be Preserved By Freezing?
Tomatoes can be preserved by freezing. As a matter of fact, the process is very simple. Just follow:
- Step 1 above and parts 1 through 8 of Step 7.
- Cool down quickly by pouring tomatoes into a cool pan and setting them down into a larger pan containing ice water.
- When completely cool, pour the tomatoes into clean freezer-safe containers. Here is the type I use, found on Amazon.
- Carefully affix the lid, label, and place into your home freezer.
Alternative Freezing Method
Or, if canning doesn’t fit your busy schedule but would like a quicker way to preserve tomatoes, freezing could be an option for you. Just take a look at my article on freezing foods to get a better idea as to whether this might work for you. I use both methods, and the taste and quality of the tomatoes are exactly the same.
Handling Spoiled Canned Foods
Home-canned foods should definitely be checked before using and also from time to time during storage to make sure it has not spoiled. If the jar is no longer sealed (The center of the jar lid will move up and down when pressed.), it should be discarded immediately.
Other signs that the food has spoiled are leakage and bulging lids on an unopened jar and upon opening, liquids spurting, signs of mold, and an unpleasant odor.
Do not taste foods that show signs of being spoiled, and discard them immediately. Canned foods that have spoiled can cause botulism and other food-related severe illnesses.
What Other Foods May Be Canned by Using This Method?
The boiling water bath method of home canning is recommended for processing high-acid foods. The pH is the measurement of how acidic a food is: Foods with a 4.6 pH or less are considered high-acid, and foods with more than a 4.6 pH are considered low-acid.
Examples of high-acid foods (pH less than 4.6) include:
- Apples, Peaches, Applesauce, Pears, Apricots, Pickled beets, Berries, Plums, Cherries, Rhubarb Cranberries, Tomatoes, Fruit juices, Tomato juice, Jams, Jellies, Fruit Spreads, Salsas, Pickles, Relishes, Chutneys, Sauces, Vinegars, and Condiments.
Canning fresh tomatoes is such a great way to have quality tomatoes all year round to make your sauces, soups, and other homemade dishes. But it is important to keep in mind a few important factors:
- The tomatoes we use for canning, whether homegrown or purchased, should be fully ripe, but not overripe.
- If you don’t have a scale handy for weighing tomatoes for canning, keep in mind that three baseball-sized tomatoes or eight plum tomatoes equal about 1 pound.
- A typical water-bath canner holds seven-quart jars or nine-pint jars at a time.
- Be sure the jar rim is perfectly clean before affixing the lid. Any particle of food, especially a tomato seed, left on the rim will prevent the lid from sealing or, if it seals, could cause the seal to fail and the tomatoes to ruin during storage.
- The canning process takes longer at high altitudes. Consult this table for further information
- Check throughout the boiling water bath process to ensure the jars are still covered by at least 1 inch of water. If you must add water, pour hot water between the jars, not directly on them.
- All home-canned foods must be processed by using safe canning methods to avoid the growth of bacteria, which can lead to botulism, a potentially deadly food-related illness. According to the USDA (United States Department of Agriculture), acid must be added to all home-canned goods, either in the form of bottled lemon juice or powdered citric acid. Their recommendation includes adding two tablespoons of bottled lemon juice or ½ teaspoon of powdered citric acid to every quart jar of tomatoes as well as every type of food that is home-canned.
I hope you’ve found this article as helpful. It was a joy to write. Coincidentally, there are a bunch of ripe tomatoes in my garden just waitin’ to be picked. Off I go!
Thanks for stoppin’ by for a visit!
Here is the link again to my resource on water bath canning. It will tell you everything you need to know about the process: How to Do Water Bath Canning | What I Learned Over 50 Years.
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