How To: Homemade Canned Tomatoes

Zak Williams — October 01, 2008

It is almost time to say goodbye to tomatoes. Soon the BLT will no longer be offered on ‘wichcraft’s menu and heirloom tomato salads will start coming down off the specials board. If you cannot let go of the fresh flavor though, there is a way to keep it going through the year. If you ever wondered how they keep that market fresh tomato flavor in their sauces in Italy, here is the answer.

Last week, I took some time to catch up with family in New Haven during our annual tomato-canning session. My great great aunt hails from just outside of Naples in a small town called Casserta, and her little tomato garden produces enough tomatoes and basil to make about 10 gallons of “canned” tomatoes.

1. Clean and drain a large batch of fresh tomatoes (any variety will do, though we prefer plum).

2. Remove the stem and surrounding area using either a knife, your hands, or a corer. Then, using your hands, tear each tomato apart to drain some of the water and remove a few seeds. Reserve this liquid.

3. Place tomatoes in pot with a little bit of the reserved “tomato water,” and cover. Turn heat to high and let the tomatoes cook for about a half hour.

4. When the tomatoes are the consistency of stew, set the pot aside and let it cool. Not cooling the tomatoes will cause you to burn your hands during the milling process.

5. While the tomatoes are cooling, clean the “canning” jars thoroughly using hot, soapy water and dry them.

6. Also, disinfect the lids by boiling them in water for a minimum of 20 minutes.

7. When the tomatoes have properly cooled, mill them using either a manual or electric food mill. If the mill is manual, re-mill the seedy, skinny by-product three or four times before discarding the residue.

8. Once the tomatoes have been milled, add a few leaves of torn-up basil and two pinches of salt to the bottom of each jar (in this case, pint jars).

9. Fill the jars leaving a centimeter or two on top. Next, seal the jars tightly to make sure that they won’t leak upon submersion.

10. When all jars are filled, place them in a pot and cover them about an inch above their lids in water and place over high-heat. Once the water is boiling, let them “cook” for twenty minutes. After the jars have been sealed and sterilized, ensure their sterilization by leaving them in the water for a minimum of three hours (leaving them overnight works well too). To ensure the jars are properly sealed, remove them and place them upside-down over paper towels or a dishcloth. If a jar is not properly sealed and leaks, discard the jar’s contents or use it immediately as it will not keep. Now you have fresh “canned” tomatoes.

Here are a few rules of thumb to keep in mind when canning tomatoes at home:

1. Be cautious of how much liquid you keep in the mix. Too much can make the mixture something akin to tomato soup, too little and you’ll have very little product relative to the raw material.

2. Tomato seeds are your friends. A recently published Cook’s Illustrated article stated that testers unanimously approved of sauces in which the seeds were kept in. Though it might not be aesthetically pleasing, the oils contained within the seeds have both flavor and body.

3. Canned tomatoes are not tomato sauce, if you use it as such you will probably be unfamiliar with the flavor. To create a well-rounded sauce, sauté a little garlic and tomato paste in olive oil, then add the canned tomatoes and 1/4 cup of wine. Cook the mixture in a covered pot over low heat for 30 minutes to three hours to allow the sauce to concentrate a bit. In the last fifteen minutes of cooking, add fresh diced plum tomatoes to give a little zip and freshness to the sauce. At the last moment, you may add fresh julienned basil if you like.