A Complete Guide to Canning Tomatoes: Preserving Summer’s Bounty

Canning tomatoes is a time-honored tradition that allows you to enjoy the vibrant flavors of summer all year round. Whether you have a bumper crop from your garden or found a great deal at the farmer’s market, learning how to can tomatoes is a valuable skill for preserving this versatile fruit. This guide will walk you through the canning process, ensuring that your tomatoes are stored safely and maintain their delicious taste.

Why Can Tomatoes?

Tomatoes are one of the best foods for home canning because they are versatile and can be used in a variety of dishes. By canning your tomatoes, you can save money, reduce waste, and enjoy fresh-tasting produce in the middle of winter. Home-canned tomatoes can be used in sauces, soups, stews, salsas, and more. Plus, you have complete control over the ingredients and can avoid preservatives or additives found in store-bought options.

Types of Tomatoes for Canning

While you can can any type of tomato, some varieties are better suited for different uses:

  • Roma Tomatoes: These are the most popular canning tomatoes due to their low moisture content, thick flesh, and fewer seeds. They are ideal for making sauces, pastes, and salsas.
  • San Marzano Tomatoes: Known for their rich flavor, these are a preferred choice for canning if you want to make authentic Italian-style tomato sauces.
  • Beefsteak and Heirloom Tomatoes: These larger, juicier varieties are great for canning diced tomatoes or tomato juice, but they may need additional processing to reduce their water content.

Regardless of the variety, select tomatoes that are ripe, firm, and free from blemishes or cracks for the best results.

Preparing Tomatoes for Canning

Before you begin canning, it’s important to properly prepare your tomatoes. Here’s how:

  1. Wash the Tomatoes: Rinse your tomatoes thoroughly to remove any dirt or residue.
  2. Blanch and Peel the Tomatoes: To easily remove the skins, blanch the tomatoes in boiling water for 30-60 seconds until the skins start to split. Immediately transfer them to an ice water bath to cool, then peel off the skins.
  3. Remove Cores and Seeds (Optional): If you prefer a smoother sauce or diced tomatoes without seeds, remove the cores and scoop out the seeds.

Equipment Needed for Canning

To safely can tomatoes, you’ll need a few basic supplies:

  • Canning Jars: Use mason jars specifically designed for canning. Pint or quart-sized jars are commonly used.
  • Lids and Bands: New, flat metal lids and reusable metal screw bands are necessary to properly seal the jars.
  • Water Bath Canner: This large pot with a rack is essential for safely processing high-acid foods like tomatoes.
  • Jar Lifter and Funnel: These tools make handling hot jars and pouring tomatoes into them much easier.

Acidifying Tomatoes: An Important Step

Even though tomatoes are naturally acidic, their pH can vary, which is why it’s recommended to add acid to ensure safe canning. Add 1 tablespoon of bottled lemon juice or ¼ teaspoon of citric acid to each pint jar (or double the amount for quart jars) before filling with tomatoes. This step prevents the growth of harmful bacteria, including botulism.

Methods for Canning Tomatoes

There are two common methods for canning tomatoes: raw pack and hot pack.

1. Raw Pack Method

In the raw pack method, tomatoes are packed into jars without pre-cooking.

  • Pack peeled and cored tomatoes tightly into the sterilized jars, leaving ½ inch of headspace at the top.
  • Press the tomatoes down gently with a spoon to release some juice and eliminate air bubbles.
  • Add the required amount of lemon juice or citric acid.
  • Fill the jars with boiling water, leaving ½ inch of headspace.
  • Wipe the jar rims, place the lids on, and secure with the bands.

2. Hot Pack Method

In the hot pack method, tomatoes are heated before packing, which helps remove more air and prevents the tomatoes from floating.

  • Place peeled and cored tomatoes in a large pot and bring them to a boil. Simmer for 5 minutes.
  • Pack the hot tomatoes and their juices into jars, leaving ½ inch of headspace.
  • Add the required amount of lemon juice or citric acid.
  • Wipe the jar rims, place the lids on, and secure with the bands.

Processing the Jars in a Water Bath Canner

The final step in canning is processing the jars to create a vacuum seal and ensure food safety.

  1. Place the filled jars in the water bath canner, ensuring they are covered by at least 1-2 inches of water.
  2. Bring the water to a rolling boil and start the timer based on your altitude and jar size:
    • For pints: Process for 35 minutes (adjust for altitude if needed).
    • For quarts: Process for 45 minutes (adjust for altitude if needed).
  3. After processing, carefully remove the jars with a jar lifter and place them on a towel-lined surface to cool. Do not disturb the jars while they cool, as this can affect the seal.
  4. Once completely cool (12-24 hours), check that the lids have sealed properly. The center of the lid should be slightly indented and not move when pressed. If a jar hasn’t sealed, refrigerate it and use within a week.

Storing Your Canned Tomatoes

Store your sealed jars in a cool, dark place. Properly canned and stored tomatoes can last up to 18 months. Always check for signs of spoilage (such as bulging lids, leaking, or foul odors) before consuming.

Conclusion

Canning tomatoes is a rewarding process that allows you to preserve the vibrant flavors of summer for use all year round. By following these steps, you can enjoy delicious, homemade canned tomatoes that are perfect for sauces, soups, and countless other recipes. With a little practice, canning tomatoes can become an enjoyable part of your seasonal kitchen routine.