Tomato Overload? Don’t Trash Them. Here’s a Quick and Easy Canning Method
Midsummer means produce is in abundance and often less expensive at food markets. If you have a small garden, then tomato plants start producing heavily in August. By canning your extra stock instead of throwing extra tomatoes in the garbage bin or compost, it is possible to preserve your tomatoes and have plenty of sauce for the fall and winter.
Each jar of homemade canned tomato sauce costs as little as $2.50 per pint. While this is 10 to 20% pricier than the cheapest can of sauce in the grocery store, it is less expensive than fresh tomato sauce that costs $5 to $7 a pint.
Canning can be overwhelming for a first timer. To start, let’s review the two standard canning methods.
Water Bath Method: The water bath method uses most of the equipment in your kitchen but is good for beginners. High-acid fruits are safe to can using the water bath method. You can make jellies, jams, sauces and salsas with this approach.
Pressure Cooker Method: Vegetables and meats with less naturally occurring acidity are not safe to can using the water bath method. Low-acid foods need the pressure cooker method to kill bacteria. A pressure cooker costs anywhere from $30 to $200 and is a sound investment for repeat canning.
Making Tomato Sauce
Tomato sauce is safe for the water bath method, as long as you increase its acidity. The National Center for Home Food Preservation at The University of Georgia suggests using lemon juice to increase the tomatoes’ acidity and minimize the risk of spoilage.
You can use tomato sauce for lasagna, chili and many other dishes!
Tools Required for Tomato Sauce
- 4 16-ounce Mason jars: $3
- Canning Tongs: $2.99
- 8-quart or 10-quart stock pot*
- Medium pot
- Shallow pot
- Large bowl
- Cutting boards
* You can also use a 5.75-Quart stock pot, but the other sizes are recommended.
- 16 to 20 midsized to large tomatoes: $9.60 to $12
- Lemon juice: 5 cents
- Salt: 5 cents
- Herbs (optional)
Keep all equipment sterile and clean. Bacteria can spread quickly in air sealed containers.
Handwash the glass jars, lids and bands in hot, soapy water. You can use a dishwasher, but make sure you rinse the jars in hot water after the dishwasher cycle. Discard any jars with cracks or damaged lids.
Step 1: Sanitize and Heat the Jars
Fill all four jars with water until the water level is close to the mouth. Fill the stock pot with two inches of water. Place all four jars in the stock pot, and bring it to a simmer. Keep the jars in place until step 3.
Put the tops and lids in a shallow pot and heat to a low boil.
Step 2: Preparing and Blanching the Tomatoes
Set aside a large bowl of ice water.
Fill the medium pot halfway with water, and heat it to a boil.
While the water heats, cut an “X” shape at the non-stem end of all the tomatoes. This shape helps the tomato peel after the blanching process.
Blanch the tomatoes by placing them in boiling water for 60 seconds, then placing them in ice water for two to three minutes.
Allow the tomatoes to cool, then peel the skins off, starting from the “X” you cut earlier. Repeat the blanching and peeling process in small batches until all the tomatoes are peeled.
Slice the tomatoes in quarters and cut out the core. Compost or dispose of the scraps.
Step 3: Cooking and Canning the Tomato Sauce
Tomato seed lovers can keep the seeds. If you prefer tomato sauce without seeds, use a strainer to sieve the sauce before cooking.
Place the tomatoes in a sauce pan. Use a potato masher or immersion blender to process the tomatoes.
Next, turn the heat to medium-high. Let the tomatoes come to a soft simmer, stirring occasionally.
For a thicker sauce, cook it for 35 to 45 minutes before canning. For a thinner sauce, can it after 60 minutes of simmering.
Five minutes before the tomato sauce is ready to can, use the tongs to empty the water from the jars into the sink.
Add lemon juice and salt into the empty jars, then ladle in the tomato sauce.
When adding the sauce to the jar, keep it below the jar’s mouth. Adding too much sauce could cause it to seal incorrectly.
Step 4: Turn Up the Heat and Seal the Cans!
Wipe the jars’ mouths and gently tighten the lids.
Add hot water to the rest of the pot until just 1 inch of the tops of the lids stick out. Boil for 35 to 45 minutes. Adjust the boiling point to compensate for your altitude. Keep the lid on the pot to retain heat.
At the 35- to 45-minute mark, open the pot and see if the Mason jars’ lids are sealed. If you press your finger on the top and it still has a spring-like feel, then the can is not sealed. Continue to boil for an additional 10 to 15 minutes until the lids seal.
Once the jars seal, remove them with tongs and place on a heat-safe countertop. Let them cool.
Your tomato sauce should last up to 1 year. Label the cans with an expiration date to keep track. With more practice, you’ll can in larger batches and save even more money.
Kat Martineau is a writer and technologist who lives in Baltimore, MD. She enjoys learning new food preservation methods, comedy and gardening. She wrote her master’s thesis on community garden movements.