How To Can Diced Tomatoes

If you’re looking for an easy way to preserve your tomato harvest, then follow these simple steps on how to can diced tomatoes. It is a fantastic way to capture that fresh summer flavor and use it all year round.

Tomatoes are incredibly versatile and are used in multiple recipes. From soups and stews to pasta sauces and salsas, having a supply of diced tomatoes in your pantry can save you time, and money and they will add a burst of freshness to your meals.

Not to mention that by canning your own tomatoes ensures you know exactly what’s in them—no preservatives or artificial ingredients. So whether you’re a seasoned canner or a just getting started as a home preserver, these easy steps will take you from start to finish for both water bath and pressure canning methods.

What Type of Tomatoes To Use To Can Diced Tomatoes

The first step in canning diced tomatoes is to pick or purchase your tomatoes. The best tomatoes to use for this recipe are varieties that are known as paste tomatoes.

You will commonly find them labeled as San Marzano, Roma, Amish Paste, or simply Plum or Paste tomatoes. They are ideal to use because they have thick walls, thin skin and an easy to remove small seed core.

Although it is alright to add a few standard, slicing tomatoes to the mixture, it is recommended that you use no more than 25% of these types of tomatoes when canning diced tomatoes.

The reason is that these larger varieties of tomatoes will produce a large volume of liquid and you will end up with mostly tomato juice instead of chunks of tomatoes.

But the most important guideline to follow is to save your low-acid tomatoes for other recipes and do not use them in this recipe.

Standard tomatoes can be canned safely with their natural pH level along with a little added lemon juice or citric acid. On the contrary, low-acid tomatoes are not safe to can without formally testing the pH level of each batch of diced tomatoes.

Therefore, use those varieties of tomatoes to slice and enjoy on a sandwich or in tomato, cucumber and onion salad (Recipe: Tomato, Cucumber and Onion Salad). Or you could also make and freeze pasta sauce to enjoy later (Recipe: Freezer Pasta Sauce Recipe).

What You’ll Need

Before you get started, these are the supplies that you will need to can diced tomatoes:

Ingredients:

• Fresh, ripe paste tomatoes (about 25 pounds for 7 quarts or 9 pints)
• Bottled lemon juice or citric acid
• Salt (optional)
• Boiling water

Equipment:

• Canning jars (pints or quarts)
• Lids and bands
• Large pot for blanching
• Knife and cutting board
• Plastic knife or thin spatula
• Jar lifter and canning funnel
• Water bath canner or Pressure canner
• Clean towels and cloths

Preparing Your Tomatoes

1. Wash the Tomatoes: Rinse your tomatoes thoroughly under cool running water.

2. Blanch and Peel: Bring a large pot of water to a boil. Then cut a small “X” on the bottom of each tomato. Drop them into the boiling water for about 30-60 seconds until the skins start to peel away. Quickly transfer them to a bowl of ice water to stop the cooking process. The skins should slip off easily.

3. Dice the Tomatoes: Remove the cores and dice the tomatoes to your preferred size. Then place the diced tomatoes and their juices in a large bowl.

Acidifying the Tomatoes

Tomatoes can sometimes be on the borderline of acidity levels needed for safe canning. Therefore to ensure safety, you must add acid to your jars:

• For Pints: Add 1 tablespoon of bottled lemon juice or 1/4 teaspoon of citric acid.
• For Quarts: Add 2 tablespoons of bottled lemon juice or 1/2 teaspoon of citric acid.

Water Bath Canning Method (Canned Diced Tomatoes)

1. Sterilize Your Jars: Place your jars in a large pot of boiling water for 10 minutes. Keep them hot until ready to use.

2. Pack the Jars: Using a canning funnel, ladle the diced tomatoes into the hot jars, however to sure to leave 1/2-inch headspace. Add a pinch of salt to each jar if desired. Then pour in the boiling water to cover the tomatoes, maintaining the 1/2-inch headspace.

3. Remove Air Bubbles: Slide a non-metallic spatula or bubble remover tool around the inside of the jar to release any trapped air bubbles. Adjust the headspace if necessary.

4. Wipe the Rims: Wipe the jar rims with a clean, damp cloth to ensure a good seal.

5. Apply Lids and Bands: Place the lids on the jars and then screw the bands on finger-tight.

6. Process in Water Bath: Place the jars in the water bath canner, ensuring they are covered by at least 1-2 inches of water. Bring to a rolling boil and process:

• Pints: 40 minutes (adjust for altitude as necessary)
• Quarts: 45 minutes (adjust for altitude as necessary)

Cool and Store: After processing, carefully remove the jars and then place them on a towel to cool for 12-24 hours. Check the seals (the lids should not flex up and down). Store in a cool, dark place.

Pressure Canning Method (Canned Diced Tomatoes)

1. Prepare Your Canner: Add the recommended amount of water to your pressure canner. Therefore be sure to follow the manufacturer’s instructions.

2. Pack the Jars: Using a canning funnel, ladle the diced tomatoes into the hot jars, leaving 1/2-inch headspace. Then add a pinch of salt to each jar if desired. Pour in boiling water to cover the tomatoes, however, be sure to maintain 1/2-inch headspace.

3. Remove Air Bubbles: Slide a non-metallic spatula or bubble remover tool around the inside of the jar to release any trapped air bubbles. Then adjust the headspace if necessary.

4. Wipe the Rims: Wipe the jar rims with a clean, damp cloth to ensure a good seal.

5. Apply Lids and Bands: Place the lids on the jars and then screw the bands on finger-tight.

6. Process in Pressure Canner: Place the jars in the pressure canner. Then lock the lid and vent steam for 10 minutes. Then, add the weight or close the valve to pressurize. Process:

• Quarts and Pints: 10 pounds of pressure for 15 minutes (adjust for altitude as necessary).

Cool and Store: Once the processing time is up allow the pressure to return to zero naturally. Wait 2 minutes before removing the weight or opening the valve. Carefully remove the lid, allowing steam to escape away from you.

Remove the jars (using a jar lifter) and then place them on a thick towel to cool for 12-24 hours. Check the seals (the lids should not flex up and down). Store in a cool, dark place.

How To Store Canned Diced Tomatoes

• Label Your Jars: Don’t forget to label your jars with the date and also the contents.
• Check Seals: If any jars didn’t seal properly, refrigerate and then use them within a week.
• Storage: Properly sealed jars can be stored in a cool, dark place for up to a year.

There you have it—two methods for canning diced tomatoes that will bring a taste of summer to your kitchen all year long. Whether you use the water bath or pressure canning method, you’ll have jars of delicious, homemade tomatoes ready for all your cooking needs.

ENJOY!