Canning tomatoes is a rewarding way to preserve summer’s bounty for year-round enjoyment. This time-honored technique allows home cooks to capture the fresh flavor and nutritional value of ripe tomatoes at their peak. Properly canned tomatoes can be safely stored for up to 18 months, providing a versatile ingredient for soups, sauces, and other dishes long after the growing season has ended.

The process of canning tomatoes involves careful preparation and adherence to food safety guidelines. Home canners have two main options: water bath canning for high-acid tomatoes or pressure canning for low-acid varieties. Both methods require thorough cleaning, peeling, and packing of the tomatoes, followed by precise processing times to ensure a secure seal and eliminate harmful bacteria.

While canning tomatoes requires some initial investment in equipment and time, the results are well worth the effort. Home-canned tomatoes offer superior taste compared to store-bought versions and allow for control over additives and salt content. With proper techniques, anyone can master this traditional preservation method and enjoy the fruits of their labor throughout the year.

Understanding Canning Basics

Canning preserves food by heating it in jars to kill bacteria and create an airtight seal. This process extends shelf life and maintains quality.

Types of Canning

Water bath canning works for high-acid foods like tomatoes. The jars are submerged in boiling water for a set time.

Pressure canning is required for low-acid foods. It uses higher temperatures to eliminate Clostridium botulinum spores.

Acidification with lemon juice or citric acid ensures safe pH levels when canning tomatoes. This step is crucial for preventing bacterial growth.

Canning Safety

Proper sanitation is vital. Clean jars, lids, and utensils thoroughly before use.

Follow tested recipes and processing times exactly. Adjustments for altitude may be necessary.

Check seals after cooling. Lids should be concave and not flex when pressed.

Store canned goods in a cool, dark place. Discard any jars with signs of spoilage like bulging lids or off odors.

Inspect jars before use. Contamination by spoilage microorganisms can cause foodborne illness.

Preparing Tomatoes for Canning

Proper preparation is crucial for successful tomato canning. Selecting quality tomatoes, cleaning them thoroughly, and preparing them correctly ensures safe and delicious canned products.

Selecting the Best Tomatoes

Choose ripe, firm tomatoes without blemishes or soft spots. Roma or San Marzano plum tomatoes are ideal for canning due to their meaty texture and low moisture content. Avoid overripe or damaged fruits, as they can compromise the final product’s quality and safety.

For whole canned tomatoes, select uniformly sized fruits. Larger tomatoes work well for crushed tomatoes or tomato sauce. Ensure all tomatoes are at peak ripeness for the best flavor.

Cleaning and Peeling

Wash tomatoes thoroughly in cool water to remove dirt and debris. Cut out stems and any bruised areas. To peel tomatoes easily, blanch them in boiling water for 30-60 seconds, then immediately plunge into ice water. The skins will slip off effortlessly.

For crushed tomatoes or sauce, remove seeds if desired. Cut peeled tomatoes into quarters and remove the core. Some canners prefer to leave seeds in for added texture and nutrients.

Preparing Tomato Products

Whole peeled tomatoes can be packed directly into jars. For crushed tomatoes, quarter the peeled fruits and crush them by hand or with a potato masher. Simmer for 5 minutes before canning.

To make tomato sauce, cook peeled and chopped tomatoes until soft. Pass through a food mill to remove seeds and create a smooth consistency. Reduce the sauce to desired thickness.

For tomato juice, simmer quartered tomatoes until soft, then strain through a fine-mesh sieve. Remove seeds and skins for a smoother texture.

Add lemon juice or citric acid to each jar to ensure safe acidity levels for all tomato products.

Canning Methods and Processing

Canning tomatoes requires proper methods and processing to ensure safety and quality. Two main approaches are used: boiling-water canning and pressure canning. Each has specific steps and considerations.

Using a Boiling-Water Canner

Boiling-water canning is a popular method for high-acid foods like tomatoes. To begin, sterilize jars, lids, and bands in hot water. Prepare tomatoes by peeling and removing cores. Fill jars with tomatoes, leaving appropriate headspace.

Add lemon juice or citric acid to each jar to ensure safe acidity levels. For quarts, use 2 tablespoons of bottled lemon juice or 1/2 teaspoon of citric acid. Pints require half these amounts.

Process filled jars in boiling water. The water must cover jars by 1-2 inches. Processing times vary based on altitude and jar size:

• 0-1,000 ft: 40 minutes for pints, 45 minutes for quarts
• 1,001-3,000 ft: 45 minutes for pints, 50 minutes for quarts

After processing, remove jars carefully and let cool undisturbed for 12-24 hours.

Using a Pressure Canner

Pressure canning offers an alternative method, especially useful for low-acid varieties or tomato products with added ingredients. This technique uses higher temperatures to eliminate harmful bacteria.

Prepare jars and tomatoes as with boiling-water canning. Fill jars, leaving 1-inch headspace. Add acidifying agents as needed. Place jars in the pressure canner with the recommended amount of water.

Follow the manufacturer’s instructions for your specific pressure canner model. Generally, process pints at 11 pounds of pressure for 15 minutes, quarts for 20 minutes. Adjust pressure for higher altitudes.

After processing, allow the canner to cool naturally. Once pressure has dropped to zero, carefully remove jars and let cool for 12-24 hours before checking seals.

Acidifying Tomatoes for Safe Canning

Acidification is a crucial step when canning tomatoes to prevent harmful bacteria growth. This process ensures the acidity level is sufficient for safe preservation.

Importance of Acidification

Tomatoes naturally have a pH level close to the safety threshold. Acidification lowers the pH, creating an environment inhospitable to dangerous bacteria like Clostridium botulinum. This step is essential for all tomato canning methods, including water bath and pressure canning.

The acidity level of tomatoes can vary based on ripeness, variety, and growing conditions. By adding acid, canners create a consistent, safe product regardless of these factors.

Proper acidification, combined with correct processing times and temperatures, prevents mold growth. Mold can raise the pH of canned tomatoes, potentially allowing botulism spores to become active.

Using Lemon Juice or Citric Acid

Two common acidifying agents for canned tomatoes are bottled lemon juice and citric acid. Bottled lemon juice is preferred over fresh due to its consistent acidity.

For quart jars:

• Add 2 tablespoons bottled lemon juice
• Or 1/2 teaspoon citric acid

For pint jars:

• Add 1 tablespoon bottled lemon juice
• Or 1/4 teaspoon citric acid

Add the acidifying agent to each jar before filling with tomatoes. This ensures even distribution throughout the product. While these additions may slightly alter the flavor, they are crucial for safety.

Vinegar can also be used but requires larger quantities and may impact taste more noticeably. Always follow tested recipes and guidelines from reputable sources for safe home canning practices.

Sealing and Storing Canned Tomatoes

Proper sealing and storage are crucial for preserving canned tomatoes safely. These steps ensure the longevity and quality of your homemade canned goods.

Checking the Seal After Canning

After the canning process, allow the jars to cool completely at room temperature for 12-24 hours. Once cooled, remove the screw bands and check each lid’s seal. Press the center of the lid – it should not flex or pop up. A properly sealed lid will be concave and firmly attached to the jar.

For an additional test, gently lift the jar by the lid’s edges. The lid should remain tightly sealed. If any jars have not sealed properly, refrigerate and use them within a few days or reprocess them within 24 hours.

Label each jar with the contents and date of canning. This helps track freshness and ensures older jars are used first.

Optimal Storage Conditions

Store canned tomatoes in a cool, dry, and dark place. The ideal temperature range is between 50°F and 70°F (10°C to 21°C). Avoid storing jars in direct sunlight or near heat sources like furnaces or hot pipes, as this can compromise the seal and affect food quality.

A pantry, basement, or dedicated storage area works well for canned goods. Ensure shelves are sturdy enough to support the weight of filled jars. For best quality, use canned tomatoes within one year of processing.

Regularly inspect stored jars for signs of spoilage, such as bulging lids, leaks, or unusual odors. Discard any jars showing these signs without tasting the contents.

Using Canned Tomatoes

Canned tomatoes offer convenience and versatility in the kitchen. They provide a reliable ingredient for countless dishes year-round.

Incorporating in Recipes

Canned tomatoes shine in chili recipes. Their concentrated flavor and soft texture blend seamlessly into the hearty mixture. For stews, diced canned tomatoes add body and acidity. They break down during cooking, enriching the broth.

Pizza sauce benefits from the consistency of canned tomatoes. Crushed varieties work well, needing minimal processing. Simply season and spread on the dough for a quick homemade pie.

Can salsa relies heavily on canned tomatoes. They provide a stable base that holds up to additional ingredients. Mix with fresh cilantro, onions, and peppers for a pantry-friendly dip.

Extended Applications

Canned tomatoes excel in pasta dishes. They form the foundation for robust sauces. Whole peeled tomatoes crush easily for a rustic texture. Diced varieties disperse evenly throughout the dish.

Soups gain depth from canned tomatoes. They contribute both liquid and substance. Puree them for a smooth base or leave chunky for added texture.

Braised meats pair well with canned tomatoes. The acidity helps tenderize tough cuts. It also balances rich flavors in slow-cooked dishes.

Canned tomatoes can be transformed into quick sauces. Simmer with herbs and spices for a versatile condiment. Use as a base for shakshuka or as a topping for grilled meats.

Tomato Preservation Alternatives

Freezing and drying offer effective ways to preserve tomatoes beyond canning. These methods help retain flavor and nutrients while providing convenience for later use.

Freezing Tomatoes

Freezing tomatoes is a simple preservation method that maintains their fresh taste. To freeze whole tomatoes, remove the stems and wash thoroughly. Blanch them in boiling water for 30-60 seconds, then plunge into ice water.

Once cooled, peel off the skins and place the tomatoes in freezer bags or containers. Remove excess air before sealing. For diced tomatoes, cut into desired pieces after peeling.

Frozen tomatoes keep well for 6-12 months. When thawed, the texture changes slightly, making them best suited for cooked dishes. Use frozen tomatoes in sauces, soups, and stews.

Drying Tomatoes

Drying concentrates tomato flavor and creates a versatile ingredient. Start by washing and slicing tomatoes into 1/4 inch thick pieces. Remove seeds if desired.

Arrange slices on dehydrator trays or baking sheets. If using an oven, set it to the lowest temperature. Dry tomatoes for 6-12 hours until leathery but pliable.

Store dried tomatoes in airtight containers in a cool, dark place. They’ll keep for 6-12 months. Rehydrate before using in recipes or enjoy as a snack. Dried tomatoes add intense flavor to pastas, salads, and spreads.

Recommended Canning Supplies

Proper equipment is essential for safely canning tomatoes. A water bath canner or large pot is the primary tool needed. This allows for boiling water to surround the jars during processing.

Mason jars are the standard for home canning. Choose jars specifically designed for canning, as they can withstand high temperatures. Quart and pint sizes work well for tomatoes.

New lids are crucial for each batch to ensure a proper seal. Bands can be reused if they’re in good condition without rust or dents.

A jar lifter makes handling hot jars easier and safer. Canning funnels help transfer tomatoes into jars without spills. A bubble remover tool eliminates air pockets.

Other useful items include:

• Clean cloth for wiping jar rims
• Wooden or plastic utensils (avoid metal)
• Large pot for blanching tomatoes
• Bowl of ice water for quick cooling

While not required for tomatoes, a pressure canner offers versatility for canning low-acid foods. It’s an investment that expands preservation options beyond tomatoes.

Tongs, cutting boards, and sharp knives round out the basic supplies needed for efficiently processing tomatoes for canning.