How to Can Fresh Tomatoes the Right Way in Easy Steps?

Tomatoes are one of those garden favorites—sweet, juicy, and good in just about everything. But when the harvest hits full swing, it can feel like tomatoes are taking over your kitchen.

That’s where canning saves the day. It’s a classic way to preserve all that fresh flavor so you can enjoy it long after summer’s gone.

People can tomatoes for the amazing flavor—nothing beats the taste of homegrown, vine-ripened fruit. Canning locks in that goodness for winter meals without any weird additives or excess salt.

It’s also cost-effective; if you’ve got a productive garden, you’re saving big on store-bought jars. Plus, there’s something truly satisfying about filling your pantry with homemade jars. Canning connects you to your food and is a rewarding tradition that’s definitely worth the effort.

Brief Overview of Canning Methods

There are a few main ways to can tomatoes, and each has its own pros and cons:

• Water Bath Canning – A popular method for high-acid foods like tomatoes. Often requires adding lemon juice or citric acid to ensure safety.
• Pressure Canning – Ideal for low-acid tomato products like sauces with added vegetables. Uses high heat to eliminate bacteria.
• Raw Pack vs. Hot Pack – Tomatoes can be packed raw or pre-cooked before sealing. Raw pack is quicker, but hot pack tends to yield better results.
• Whole, Diced, Crushed, or Sauced – You can preserve tomatoes in a variety of forms depending on your future use: whole peeled, diced, crushed, or even as a purée or sauce.

How to Can Fresh Tomatoes in a Water Bath Canner?

Water bath canning is one of the simplest and most accessible methods for preserving tomatoes.

It’s especially suited to beginners because it doesn’t require the specialized equipment that pressure canning does. Plus, tomatoes — being a high-acid food (with added lemon juice or citric acid) — are ideal for this method.

By canning tomatoes in a water bath, you preserve their rich flavor and texture, making them perfect for sauces, stews, soups, and casseroles all year long. And when done correctly, water bath canning offers a shelf life of 12 to 18 months with excellent quality.

Equipment You’ll Need

• Water bath canner (or a deep stockpot with a canning rack)
• Canning jars (pints or quarts)
• Two-piece canning lids (new lids, reusable rings)
• Jar lifter
• Bubble remover (plastic spatula or chopstick)
• Wide-mouth funnel
• Large stockpot for blanching and cooking tomatoes
• Slotted spoon
• Ladle
• Bowl of ice water
• Clean kitchen towels

Ingredients

• Fresh, ripe tomatoes (Roma, San Marzano, or other paste types are best)
• Bottled lemon juice or citric acid
• Canning salt (optional, for flavor only)
• Boiling water or tomato juice (for hot-packing)

Step-by-Step: Water Bath Canning Tomatoes

This guide focuses on peeled whole or halved tomatoes packed in water or juice, using the hot-pack method — which yields better quality and fewer issues with floating or siphoning.

1. Select and Prepare Tomatoes

Choose firm, ripe tomatoes that are free from blemishes or bruises. Roma and paste types are ideal because they have more flesh and less water.

• Wash tomatoes thoroughly.
• Remove stems and cut a small “X” on the bottom of each tomato.

2. Blanch and Peel the Tomatoes

Blanching loosens the skin for easy removal.

• Bring a large pot of water to a boil.
• Drop tomatoes in for 30–60 seconds, just until the skins start to split.
• Immediately transfer them to a bowl of ice water to stop cooking.
• Slip off the skins by hand.
• Remove cores and halve or leave whole, as you prefer.

3. Heat the Tomatoes (Hot Pack)

Although raw-pack is an option, hot-packing (briefly cooking the tomatoes before canning) improves texture, reduces floating, and helps prevent jars from leaking during processing.

• Place peeled tomatoes into a large pot.
• Bring to a simmer and heat for about 5–10 minutes, stirring gently.
• Do not boil them into sauce — just warm them through.

4. Prepare Jars and Lids

• Wash jars, lids, and rings in hot soapy water.
• Keep jars hot until ready to use (place in warm water or oven at 170–180°F).
• Keep lids in a pan of hot water, according to the manufacturer’s instructions.

5. Add Acid to the Jars

To ensure food safety, all tomatoes must be acidified — even if they taste acidic. Modern tomatoes may not have enough acid for safe water bath canning without this step.

• For quart jars: add 2 tablespoons bottled lemon juice or ½ teaspoon citric acid
• For pint jars: add 1 tablespoon bottled lemon juice or ¼ teaspoon citric acid

Do this before filling the jars.

6. Pack Tomatoes Into Jars

• Use a wide-mouth funnel to fill the jars with hot tomatoes.
• Gently press down to release trapped air.
• Add boiling water or tomato juice to cover the tomatoes, maintaining ½-inch headspace.
• Optional: Add ½ teaspoon canning salt per pint (or 1 tsp per quart) for flavor.
• Remove air bubbles with a non-metallic tool (plastic spatula or bubble remover).
• Wipe rims clean with a damp cloth.
• Apply lids and screw bands on fingertip-tight.

7. Process in a Water Bath Canner

• Fill your water bath canner halfway with hot water and bring to a gentle simmer.
• Place filled jars into the canner using a jar lifter.
• Ensure jars are covered by at least 1 inch of water above the lids.
• Cover and bring to a rolling boil.

Processing Times:

• Pints: 35 minutes
• Quarts: 45 minutes

Important: Adjust processing time for elevation.

• 1,001–3,000 ft: add 5 minutes
• 3,001–6,000 ft: add 10 minutes
• Above 6,000 ft: add 15 minutes

Maintain a rolling boil for the entire time. Do not reduce the heat once the boil starts.

8. Remove and Cool Jars

• After processing, turn off the heat and remove the lid.
• Let jars sit in the canner for 5 minutes before removing.
• Use a jar lifter to carefully transfer jars to a towel-lined surface.
• Let them cool undisturbed for 12–24 hours.

Do not tilt or shake jars during cooling — this could compromise the seal.

9. Check Seals and Store

• Once jars are cool, check the seals:
  • Lids should be concave (slightly dipped).
  • They should not flex up and down when pressed in the center.
• If sealed properly, remove the screw bands.
• Label each jar with the contents and date.
• Store in a cool, dark, and dry place.

Any unsealed jars should be refrigerated and used within a week, or reprocessed with a new lid.

Note: Leave enough space in jars and always acidify with bottled lemon juice or citric acid for safety. Label each jar with the date and tomato type for easy tracking and use.

How to Can Tomatoes with a Pressure Canner?

Canning tomatoes is one of the best ways to capture the essence of summer and stock your pantry with something homemade and flavorful.

While water bath canning is popular for its simplicity, pressure canning offers unmatched safety and flexibility — especially when you want to make more than just plain tomatoes.

Why pressure can? Because not all tomato-based recipes are safe for water bath canning. Modern tomato varieties often have lower acidity, and when you start adding vegetables like onions, garlic, peppers, or herbs to your sauces or soups, the acidity drops even more.

This makes pressure canning essential — it reaches temperatures of 240°F or higher, killing dangerous bacteria, including Clostridium botulinum, the one that causes botulism.

Pressure canning is the method of choice for:

• Tomato sauces with vegetables
• Tomato soup bases
• Salsa recipes not tested for water bath safety
• Stewed tomatoes
• Tomatoes without added acid

Let’s walk through the complete process of pressure canning tomatoes, focusing on a basic tomato sauce recipe that’s safe, tasty, and versatile.

Step-by-Step Guide: Pressure Canning Tomatoes

This method is for a basic tomato sauce — plain or lightly seasoned. For more complex recipes (like salsa, spaghetti sauce with meat, or thick purées), always use tested recipes and follow USDA or Extension Service guidelines.

Equipment You’ll Need

• Pressure canner (dial gauge or weighted gauge)
• Canning jars (pint or quart)
• Two-piece lids (new lids and rings)
• Jar lifter
• Large stockpot or saucepot
• Food mill or sieve (optional but recommended)
• Funnel, ladle, bubble remover
• Clean kitchen towels

Ingredients

• 20 lbs fresh, ripe tomatoes (Roma/paste types are ideal)
• 2 tablespoons bottled lemon juice or ½ tsp citric acid per quart jar (1 Tbsp or ¼ tsp per pint) – optional but recommended
• 1–2 teaspoons salt per quart (optional, for flavor only)
• Optional herbs: bay leaf, basil, oregano (use fresh or dried, sparingly)

1. Choose and Prepare Tomatoes

Pick high-quality, fully ripe tomatoes. Roma, San Marzano, or other paste varieties are preferred because they have fewer seeds and lower water content, which makes a thicker, more flavorful sauce.

• Wash tomatoes thoroughly under cool running water.
• Remove stems, core the tops, and cut into quarters.

2. Cook and Soften Tomatoes

Place your cut tomatoes in a large saucepot. As they begin to soften, crush them with a spoon or potato masher to release juice and prevent sticking. Bring to a boil and simmer for 10–15 minutes, stirring occasionally.

3. Remove Skins and Seeds (Optional but Recommended)

For a smooth sauce:

• Run the softened tomatoes through a food mill or fine mesh strainer to remove skins and most seeds.
• Return the purée to the pot.

If you don’t mind a rustic, chunky texture, you can skip this and proceed with a coarser sauce.

4. Simmer and Thicken

Simmer the sauce uncovered until it reduces to your preferred thickness. This may take 30 minutes to 2 hours depending on how watery the tomatoes are and how thick you want your sauce. Stir frequently to avoid scorching, especially as it thickens.

Avoid adding oil, dairy, or meat — these are not safe for pressure canning unless following a tested, approved recipe.

5. Acidify the Sauce (Optional but Safer)

Even though you’re pressure canning, it’s recommended to add acid for extra safety and flavor preservation:

• Add 2 tablespoons bottled lemon juice or ½ teaspoon citric acid per quart.
• Add 1 tablespoon bottled lemon juice or ¼ teaspoon citric acid per pint.

This ensures consistent acidity even in less-acidic modern tomatoes.

6. Prepare Jars and Lids

• Wash jars, lids, and bands in warm soapy water.
• Rinse well and keep jars warm (in hot water or the oven).
• Prepare your lids according to the manufacturer’s instructions.

7. Fill the Jars

• Using a funnel, ladle hot sauce into jars, leaving 1 inch headspace.
• Optional: Add ½–1 tsp of salt per jar for flavor.
• Use a bubble remover or plastic spatula to release air bubbles.
• Wipe the rims with a clean, damp cloth.
• Place lids on jars and screw bands on fingertip-tight.

8. Load the Pressure Canner

• Add 2–3 inches of water to the bottom of the canner (check your model’s instructions).
• Place filled jars on the rack inside the canner.
• Lock the lid and heat on high until steam flows steadily from the vent.
• Let it vent for 10 minutes to remove air.

9. Pressurize and Process

Once vented, close the vent and let the pressure build. Follow these guidelines:

Process pint jars at 10 PSI (weighted) or 11 PSI (dial) for 20 minutes; quarts for 25 minutes. Always adjust for altitude if needed.

Altitude Adjustments:

• For over 1,000 ft, increase pressure: use 15 PSI weighted gauge or consult altitude chart for dial gauge.

Keep a steady pressure for the entire time. Adjust heat to maintain pressure — do not let it drop, or you’ll have to start timing all over again.

10. Depressurize and Cool

• Once time is up, turn off the heat and let pressure return to zero naturally.
• Do not open the vent or force-cool the canner.
• Once depressurized, open the lid carefully, facing it away from you.
• Let jars sit in the canner for 5–10 minutes before removing.

11. Remove, Cool, and Store Jars

• Using a jar lifter, transfer jars to a towel-covered surface.
• Let cool undisturbed for 12–24 hours.
• Check seals: lids should be flat or slightly concave.
• Label jars with the date.
• Store in a cool, dark place for up to 12–18 months.

If a jar didn’t seal, refrigerate it and use within a week or reprocess with a new lid.

Conclusion

Pressure canning tomatoes offers more versatility than water bath canning, allowing you to make rich sauces, add herbs, or even mix in vegetables.

While it requires more equipment and attention to detail, it ensures your canned goods are safe, shelf-stable, and free of preservatives.

This method is perfect for storing big batches of tomato sauce for dishes like chili, lasagna, and pizza, all with the fresh taste of homegrown tomatoes. Once you master it, you’ll never go back to store-bought!