Quick Answer: Learning how to can tomatoes at home is a simple way to preserve fresh summer tomatoes for year-round cooking. By using a water bath canner, properly acidifying each jar with bottled lemon juice or citric acid, and following safe canning practices, you can enjoy homemade canned tomatoes for 12 to 18 months.
❤️ Why You’ll Love This Guide
- Preserve fresh tomatoes at peak ripeness.
- Save money by stocking your pantry during tomato season.
- Control exactly what goes into every jar.
- Enjoy homemade tomatoes for up to 18 months.
- Easy step-by-step instructions that are beginner-friendly.
I love canning tomatoes because it’s one of the most rewarding ways to preserve the flavors of summer. There’s nothing quite like opening a jar of home-canned tomatoes in the middle of winter and knowing you preserved them yourself. With just a few ingredients and the right equipment, you can stock your pantry with delicious tomatoes that are ready for soups, sauces, stews, and countless family meals.
Home canning also gives you complete control over your ingredients. You choose the tomato variety, adjust the salt to your taste, and avoid unnecessary preservatives or additives. Whether you’re harvesting tomatoes from your own garden or taking advantage of seasonal produce, this guide will walk you through the process step by step.
Ingredients You’ll Need
Main Ingredients
- 20–25 pounds (9–11 kg) fresh tomatoes – Roma, San Marzano, or other paste tomatoes are recommended because they produce the best texture and flavor after canning.
- 2 tablespoons bottled lemon juice per quart jar or ½ teaspoon citric acid per quart jar – Essential for safely acidifying the tomatoes before processing.
- 1 teaspoon canning salt per quart (optional) – Adds flavor but is not required for preservation.
Equipment You’ll Need
- Water bath canner or large stockpot
- Quart or pint Mason jars
- New canning lids
- Reusable screw bands
- Jar lifter
- Wide-mouth canning funnel
- Bubble remover tool or plastic chopstick
- Large pot for blanching tomatoes
- Large bowl filled with ice water
- Clean kitchen towels
- Ladle
How to Can Tomatoes at Home
1. Prepare Your Equipment
Fill your water bath canner with water and begin heating it until it reaches a gentle simmer (about 180°F/82°C). Wash the jars in hot, soapy water and keep them hot until ready to use. Place the lids in hot—not boiling—water to soften the sealing compound.
2. Prepare the Tomatoes
Wash the tomatoes thoroughly and remove any bruised or damaged spots. Blanch them in boiling water for 30–60 seconds, then immediately transfer them to an ice bath. Once cooled, peel away the skins, remove the cores, and cut the tomatoes into halves or quarters. Removing the seeds is optional.
3. Fill the Jars
Add 2 tablespoons bottled lemon juice (or 1 tablespoon for pint jars) to each hot jar. If using, add the canning salt. Pack the prepared tomatoes tightly into the jars, pressing gently to release juice. Add boiling water if necessary and leave ½ inch headspace.
4. Remove Air Bubbles
Slide a bubble remover tool or plastic chopstick around the inside of each jar to release trapped air. Wipe the rims clean with a damp cloth, place a lid on each jar, and tighten the bands until fingertip-tight.
5. Process the Jars
Place the filled jars into the simmering water bath canner, ensuring they are covered by 1–2 inches of water. Bring the water to a full rolling boil and process pint jars for 40 minutes or quart jars for 45 minutes at sea level. Add additional processing time for higher elevations if needed.
6. Cool and Check the Seals
Turn off the heat and let the jars rest in the canner for 5 minutes before removing them. Place the jars on a towel-lined counter and allow them to cool undisturbed for 12–24 hours. Check each seal by pressing the center of the lid. Properly sealed jars can be stored in a cool, dark place for 12–18 months. Refrigerate any jars that did not seal and use them within one week.
Tips
- Choose ripe, firm tomatoes for the best texture and flavor after canning.
- Always use bottled lemon juice or citric acid to ensure safe acidity levels. Fresh lemon juice should not be substituted.
- Measure the ½-inch headspace carefully to help ensure a proper seal during processing.
- Use new canning lids every time to improve sealing success.
- Label each jar with the date and contents before storing it in a cool, dark pantry.
Storage & Make-Ahead
Pantry Storage
Store sealed jars in a cool, dark place (50–70°F / 10–21°C) for the best quality. Properly canned tomatoes maintain their quality for 12–18 months. Remove the metal bands before long-term storage to prevent rusting.
After Opening
Once opened, refrigerate the tomatoes and use them within 5–7 days.
Check for Spoilage
Inspect stored jars regularly. Discard any jars with bulging lids, leaks, mold, cloudiness, or unpleasant odors. When in doubt, throw it out.
Variations to Try
Crushed Tomatoes
Crush peeled tomatoes by hand or with a potato masher before packing into jars. This creates a thicker, sauce-ready product.
Italian-Style Tomatoes
Add 1-2 fresh basil leaves and 1 clove of garlic to each jar before filling with tomatoes. The herbs infuse subtle flavor during storage.
Tomato Juice
Simmer chopped tomatoes until soft, then run through a food mill. Heat juice to boiling and process pint jars for 35 minutes or quarts for 40 minutes.
Seasoned Tomatoes
Add ½ teaspoon dried oregano, ¼ teaspoon black pepper, or a pinch of red pepper flakes to each jar for pre-seasoned tomatoes ready for cooking.
Ways to Use Your Canned Tomatoes
Open a jar for quick marinara sauce; just simmer with garlic, olive oil, and herbs for 20 minutes.
Use canned tomatoes as the base for creamy chicken enchilada soup or hearty winter minestrone.
Crush them into chili, curry, or stew for instant depth of flavor. The canning process actually intensifies the tomato taste.
Blend canned tomatoes with fresh ingredients for bruschetta topping or salsa. They’re already cooked, so they need minimal prep.
Add them to marry me chicken pasta for a sauce that clings perfectly to every noodle.
Common Mistakes to Avoid
Using fresh lemon juice instead of bottled is the most dangerous mistake. The pH can vary too much to ensure safety.
Skipping the water bath processing because “my grandmother never did it” risks botulism poisoning. Modern safety standards exist for good reasons.
Reusing old lids saves pennies but costs you hours of work when jars don’t seal. Always use new lids.
Processing jars that aren’t fully covered with water creates uneven heating and potential spoilage.
Storing jars with bands on can hide seal failure. You won’t notice a broken seal until you try to open a spoiled jar months later.
Frequently Asked Questions
Do I need a pressure canner for tomatoes?
No. Tomatoes are high-acid foods that can be safely processed in a water bath canner as long as you add lemon juice or citric acid to each jar.
Can I use tomatoes from my garden?
Absolutely. Home-grown tomatoes are ideal for canning. Just make sure they’re ripe, unblemished, and properly acidified with lemon juice.
What if my jars don’t seal?
Refrigerate unsealed jars immediately and use within a week. You can also reprocess within 24 hours using new lids, though quality may suffer.
How do I know if canned tomatoes have gone bad?
Look for bulging lids, leaks, mold, cloudiness, or off odors. Never taste suspicious canned goods; discard them immediately.
Can I add onions or peppers to my canned tomatoes?
Not safely in a water bath canner. Low-acid vegetables require pressure canning. Stick to tomatoes, lemon juice, and dried herbs only.
Why did my tomatoes separate in the jar?
This is normal. Tomato solids settle, and liquid rises during storage. Just shake or stir before using.
Conclusion
I love canning tomatoes because it lets me capture the fresh flavors of summer and enjoy them throughout the year. Once you learn the basic process—preparing the tomatoes, properly acidifying the jars, maintaining the correct headspace, and following safe water bath canning procedures—you’ll have a pantry full of homemade tomatoes ready for soups, sauces, pasta dishes, and countless family meals. Whether you’re preserving tomatoes from your own garden or taking advantage of peak-season produce, home canning is a rewarding skill that pays off with every jar you open.
