How to Can Tomatoes
Tomato season is winding down, but you still have time to jump in on the canning action. Late tomato varieties are still rolling in from the fields. Simply call different farms or produce markets in your area.
For the past two years, I have paid around 50¢ per pound for larger orders of canning tomatoes. One quart jar will hold around 2.5 pounds.
I love canning tomatoes for two simple reasons:
- They require no finesse. Using this method, you can cram the tomatoes into the jars whole, creating juice from the tomatoes themselves.
- They are so versatile. Canned tomatoes are the foundation for a hundred different winter meals. The quarts can be used as a base for chili, soup, or spaghetti sauce. The pints are great for salsa, soups, stews, or sauces. You can use a food processor or blender to get the desired consistency or simply cook the tomatoes down until they break apart.
Below is an illustrated guide to canning whole, peeled tomatoes using the cold pack method. Everybody has their own little quirks or variations, but this is a basic guide to get you started:
These are the ingredients and equipment you will need:
- Water bath canner & jar lifter. Canners can be picked up for under $20 and jar lifters for a couple bucks at your local Walmart, Bi-Mart, Fred Meyer, or Amazon. Both tools are great investments that can be re-used year after year. (The large pot in this picture is actually a pressure canner, but I have been using it loose-lidded for water bath canning.)
- Quart or pint-sized jars. Jars are probably the biggest investment if you are interested in getting serious about canning. However, once you have a good collection built up, you are good to go. Check with your grandma or Craigslist for used jars.
- Lids & rings/bands. Lids are only good for one use (unless you use these reusable lids), but are relatively inexpensive. Look for coupons at the beginning of the summer and discounts at the end of fall. Rings can be re-used.
- Sharp paring knife (here’s a highly-rated, inexpensive option)
- Vinegar or lemon juice, salt (optional), and of course, tomatoes
- Shallow pot for blanching
Clean, check, and sanitize your jars and lids.
Check the rims of your jars for nicks that will prevent sealing. Then run the jars through the dishwasher. If you don’t have a dishwasher, you could also submerge the jars in a canner full of water and bring to a boil for 10 minutes.
Place the lids in simmering water for 10 minutes, though the manufacturers are saying that you can skip this step now. I don’t bother sanitizing the rings as they don’t come into contact with food; simply wash as needed.
Next, prep the canner and the jars.
Fill the canner about halfway full of water, place the lid on, and turn on low. Don’t let the water get too hot; you just want to get a jump start on bringing it to a simmer.
Measure 4 T of bottled vinegar or 2 T bottled lemon juice (preferred) and 1 t. of canning salt (optional) into each quart-sized jar (halve the amounts for pints).
The lemon juice helps you achieve a safe amount of acid; the salt enhances/preserves the flavor.
Okay, enough stalling. Now, it’s time to deal with the tomatoes. Actually, they are really easy to work with.
Using a sharp paring knife, core each tomato by removing the stem section.
If you are canning with someone else (which I highly recommend, both for speed and sanity), you can get a coring-blanching assembly line going. If you are on your own, core all of your tomatoes first. It makes the next step much easier and faster.
If you accidentally core too many tomatoes, just toss them in a pan and make Roasted Marinara Sauce.
Next, place the cored tomatoes in a shallow pot of simmering water.
Blanch for 30-60 seconds and remove with a slotted spoon. You can stick the blanched tomatoes in a bowl of ice water to shock them. I usually just pile them up in a couple of big bowls to cool off.
Remove the tomato skins.
By the way, some people also advocate slicing a quick “x” on the bottom of each tomato before blanching. As long as you are working with ripe tomatoes, you really don’t need this step. The skins will slip off easily. If your tomatoes are a tad on the green side, go for the x. It will make peeling easier.
Now for the fun part; fill the jars with the peeled tomatoes.
If your tomatoes are small, you can leave them whole. If your tomatoes are large, cut them in halves or fourths, whatever size is manageable. You don’t need to be timid with them.
When the jar is full and finished, the tomatoes should come to the bottom of the jar threads, leaving about 1/2 inch of headspace at the top of the jar.
Run a plastic utensil between the jar and the tomatoes, pressing into the tomatoes to release any trapped air bubbles.
Using a clean towel, wipe the rims of each jar. Place a lid on top and screw on the rings finger-tight.
IMPORTANT: Check the water in the canner. It should be warm but not scalding hot. Placing cool jars into a hot canner is a bad combination.
Gently lower the jars into the warm water using your fingers or jar lifter. Once all of your jars are in, make sure the tops are covered with 1-2 inches of water. Place the lid back on the canner.
Bring to a gentle rolling boil. Maintain a constant boil and process both pints & quarts for 85 minutes.
When the timer rings, remove the hot jars with the jar lifter and place on a towel or rack to cool.
As the jars cool, the lids will suck in and seal. You can check the seals by running your fingertips lightly over the lids. Any jars that do not seal can be dumped in a new jar with a new lid to process again or placed in the refrigerator for use in the near future.
Don’t worry if your tomatoes rise to the top and separate slightly from the juice. It may look funny, but they will taste just fine.
After 8-12 hours, remove the rings, rinse off the jars, and store them in a cool, dry place.
We have several canning posts here on the blog. Check them out!
- Canning for Beginners FAQ’s
- Canning Applesauce
- Canning Peach Vanilla Bean Jam
- Canning Peaches
- Canning Sweet Cherries
- Canning Tomatoes
- Water Bath Canning Guide
- Water Bath Canning Equipment
Plus follow our Preserve board on Pinterest for more great canning and preserving recipes.
For more information on canning tomatoes, check out these great resources:
- Pick Your Own – How to Can Fresh Tomatoes
- Food in Jars – Canning Whole Peeled Tomatoes
- NCHFP – Selecting, Preparing, and Canning Tomatoes
- Ball Canning
Are you new to canning? Be sure to go through our Home Canning Guide posts for a beginners guide, equipment suggestions, and recipes!
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