Best Method for Canning Tomatoes Step by Step Guide

Last Updated on October 22, 2026 by D. Ruddy

Preserving the harvest at home starts with finding the best method for canning tomatoes that keeps flavor fresh and safe for your pantry. Whether you’re a beginner or seasoned canner, choosing the right technique ensures vibrant taste and prevents spoilage. This guide covers everything from preparation to storage so you can enjoy garden-ripe tomatoes all year long.

The best method for canning tomatoes is the water bath canning process for high-acid varieties or pressure canning for low-acid types. This ensures safety and preserves freshness for up to 18 months when done correctly.

What You Need for Canning Tomatoes

Before you start, gather the right tools and ingredients. Fresh, firm tomatoes are essential—choose ripe but not overripe ones. You’ll also need canning jars, lids, and bands that are free from cracks or defects.

A water bath canner or pressure canner is non-negotiable for safety.

Additional supplies include a jar lifter, canning funnel, bubble remover or non-metallic spatula, and a large pot for pre-heating lids. Acidification is critical for safety, so have lemon juice or citric acid on hand. For low-acid tomatoes, a pressure canner is a must.

• Fresh tomatoes: 20-25 pounds yields about 7 quarts or 14-18 pints
• Canning jars: Quart or pint-sized, sterilized
• Lids and bands: New lids for each jar; bands can be reused if in good condition
• Canner: Water bath for high-acid tomatoes, pressure canner for low-acid
• Acid: Bottled lemon juice (5% acidity) or citric acid
• Salt: Optional, for flavor (canning or pickling salt recommended)
• Tools: Jar lifter, funnel, bubble remover, lid wand, timer

Tip: Use a food scale to measure tomatoes accurately. A general rule is 21 pounds for 7 quarts or 13 pounds for 9 pints.

Choosing the Right Tomatoes for Canning

Not all tomatoes are created equal when it comes to canning. The best varieties are meaty with fewer seeds and less juice, which means thicker sauces and whole tomatoes that hold their shape. Roma and San Marzano tomatoes are top choices for their low moisture content and rich flavor.

Heirloom tomatoes can work but may require more prep to remove excess liquid. Avoid overripe or bruised tomatoes, as they can affect the quality and safety of your canned goods. Organic tomatoes are ideal if you want to avoid pesticides, but conventional tomatoes are fine if washed thoroughly.

For the best results, mix tomato varieties if needed, but stick to meaty types for thicker products. Always remove stems and wash tomatoes thoroughly before processing.

Preparing Tomatoes for Canning

Proper preparation is key to safe and delicious canned tomatoes. Start by washing tomatoes under running water to remove dirt and bacteria. Remove stems and any bruised spots.

For whole tomatoes, you’ll need to peel them first—blanching is the easiest method.

To blanch, cut an “X” on the bottom of each tomato, then drop them into boiling water for 30-60 seconds. Immediately transfer to an ice bath to cool. The skins will slip off easily.

For crushed tomatoes or sauces, you can skip peeling and simply core and quarter the tomatoes before cooking.

1. Wash: Rinse tomatoes under cold water and pat dry.
2. Core: Remove stems and any tough core areas.
3. Blanch (for peeling): Score the skin, boil for 30-60 seconds, then ice bath.
4. Peel: Remove skins if making whole tomatoes or sauces.
5. Quarter or halve: Cut tomatoes as needed for your recipe.
6. Pre-cook (optional): Simmer tomatoes for 5-10 minutes to reduce liquid for sauces.
7. Add acid: Add 1 tablespoon of lemon juice per pint or 2 tablespoons per quart to jars.

Warning: Never skip the acidification step. According to the USDA, adding lemon juice or citric acid is critical to prevent botulism in home-canned tomatoes.

Step by Step Water Bath Canning Method

Water bath canning is the most common and safest method for canning tomatoes when they’re properly acidified. This method works for high-acid foods like tomatoes with added lemon juice or citric acid. Here’s how to do it right.

Start by sterilizing your jars and lids. Keep jars hot until you’re ready to fill them to prevent breakage. Prepare your tomatoes as described above, then pack them into jars according to your recipe—raw pack or hot pack methods are both acceptable.

Raw Pack Method

1. Pack tomatoes: Fill jars with raw, peeled tomatoes, pressing down gently to remove air pockets.
2. Add liquid: Cover tomatoes with hot water, tomato juice, or light syrup, leaving ½-inch headspace.
3. Add acid: Include 1 tbsp lemon juice per pint or 2 tbsp per quart.
4. Remove bubbles: Use a bubble remover or non-metallic spatula to release air bubbles.
5. Adjust headspace: Ensure ½-inch space remains at the top.
6. Wipe rims: Clean jar rims with a damp cloth to ensure a good seal.
7. Apply lids: Place lids on jars and screw bands on until fingertip-tight.

Hot Pack Method

1. Pre-cook tomatoes: Simmer tomatoes for 5-10 minutes to soften and reduce liquid.
2. Pack hot tomatoes: Fill jars with hot tomatoes, pressing gently.
3. Add hot liquid: Cover with hot cooking liquid, tomato juice, or water, leaving ½-inch headspace.
4. Add acid: Include the required lemon juice or citric acid.
5. Remove bubbles: Release air bubbles with a non-metallic tool.
6. Adjust headspace: Maintain ½-inch space at the top.
7. Wipe and lid: Clean rims, apply lids, and screw bands fingertip-tight.

Processing in Water Bath Canner

1. Fill canner: Place jars on the rack in the canner, ensuring they’re covered by 1-2 inches of water.
2. Bring to boil: Heat water to a full rolling boil.
3. Process: Start timer once water is boiling. Pints need 35-40 minutes, quarts 40-45 minutes (adjust for altitude).
4. Cool: Remove jars and place on a towel-lined countertop to cool undisturbed for 12-24 hours.
5. Check seals: After cooling, check that lids are concave and don’t pop when pressed.

According to the National Center for Home Food Preservation, altitude affects processing times because water boils at lower temperatures at higher elevations. Always adjust your processing time based on your altitude for safety.

Pressure Canning for Low-Acid Tomatoes

If you’re canning tomatoes without added acid or using low-acid varieties, pressure canning is the only safe method. This process reaches higher temperatures to kill harmful bacteria like Clostridium botulinum, which causes botulism.

Pressure canning is also recommended for tomato mixtures with vegetables or meats, as these ingredients can lower the overall acidity. The process is similar to water bath canning but requires a pressure canner and specific PSI settings based on your altitude and jar size.

1. Prepare jars and tomatoes: Sterilize jars and prepare tomatoes as described earlier.
2. Pack jars: Use the raw or hot pack method, leaving 1-inch headspace for pressure canning.
3. Add liquid: Cover tomatoes with hot water or tomato juice, maintaining 1-inch headspace.
4. Remove bubbles: Use a bubble remover to eliminate air pockets.
5. Wipe rims and lid: Clean jar rims, apply lids, and screw bands fingertip-tight.
6. Load canner: Place jars on the rack in the pressure canner, following manufacturer instructions.
7. Process: Follow the canner’s instructions for your altitude and jar size (typically 10-15 PSI for weighted gauges or 11-15 PSI for dial gauges).
8. Cool: Let pressure drop naturally, then remove jars and cool undisturbed for 12-24 hours.

Pressure canning times and PSI settings vary by altitude and canner type. Always refer to your canner’s manual or the USDA Complete Guide to Home Canning for precise instructions. The University of Georgia’s National Center for Home Food Preservation reports that improper canning methods are a leading cause of foodborne illness from home-preserved foods.

Common Mistakes to Avoid When Canning Tomatoes

Even experienced canners make mistakes that can compromise safety or quality. One of the most critical errors is skipping the acidification step. Without enough acid, tomatoes may not reach a safe pH level, increasing the risk of botulism.

Another common mistake is using jars that aren’t designed for canning. Mason jars are made to withstand the high heat of canning, while commercial food jars (like pasta sauce jars) are not and may break. Overfilling jars or not leaving enough headspace can also lead to seals failing or liquid siphoning out during processing.

• Skipping acid: Always add lemon juice or citric acid to ensure a safe pH below 4.6.
• Using damaged jars: Inspect jars for cracks, chips, or defects before use.
• Reusing lids: Lids have a sealing compound that can only be used once. Always use new lids.
• Underprocessing: Follow processing times precisely—don’t shorten them to save time.
• Overfilling jars: Leave the recommended headspace (½-inch for water bath, 1-inch for pressure canning).
• Not removing air bubbles: Trapped air can prevent proper sealing and lead to spoilage.
• Cooling jars too quickly: Let jars cool undisturbed for 12-24 hours to allow seals to set properly.
• Ignoring altitude adjustments: Processing times increase with altitude—always adjust accordingly.

Important: If a jar doesn’t seal after cooling, you can reprocess it within 24 hours using a new lid. Alternatively, refrigerate and use the contents within a few days.

Pro Tips for Perfect Canned Tomatoes

To take your canned tomatoes to the next level, consider these expert tips. Adding a pinch of salt to each jar can enhance flavor, though it’s optional. For whole tomatoes, packing them tightly but gently helps them retain shape and prevents floating.

If you’re canning tomato sauce or juice, simmering the tomatoes first reduces liquid and intensifies flavor. For a smoother sauce, use a food mill or strainer to remove seeds and skins. Labeling your jars with the date and contents helps you keep track of your pantry stock and ensures you use the oldest jars first.

• Use a food mill: For smooth sauces, remove seeds and skins with a food mill or fine-mesh strainer.
• Add herbs: Enhance flavor with fresh basil, oregano, or garlic (use bottled lemon juice for safety with herbs).
• Prevent floating: Pack tomatoes tightly and remove air bubbles to minimize floating in jars.
• Test pH: Use pH strips to test your canned tomatoes—safe pH is below 4.6.
• Store properly: Keep jars in a cool, dark place (50-70°F) for best shelf life.
• Rotate stock: Use the oldest jars first to maintain freshness.
• Reuse jars: Save and reuse jars and bands (but not lids) for future canning sessions.

How to Store Canned Tomatoes

Proper storage is essential to maintain the quality and safety of your canned tomatoes. Once jars are cooled and sealed, remove the bands to prevent rust and check the seals. Store jars in a cool, dark, and dry place like a pantry or cellar.

Avoid storing jars in direct sunlight or near heat sources, as this can degrade quality and cause seals to fail over time. Ideal storage temperature is between 50-70°F. If stored properly, canned tomatoes can last 12-18 months, though they’re best used within a year for peak flavor.

1. Cool completely: Let jars cool undisturbed for 12-24 hours before storing.
2. Check seals: Press the center of the lid—if it doesn’t pop, it’s sealed. Refrigerate unsealed jars and use within a few days.
3. Remove bands: Take off screw bands to prevent rust and store them separately.
4. Label jars: Write the date and contents on the lid or a label for easy identification.
5. Store upright: Keep jars upright to maintain seal integrity.
6. Inspect regularly: Check jars periodically for signs of spoilage like bulging lids, leaks, or mold.

Warning: If you notice any signs of spoilage—bulging lids, off odors, mold, or liquid seeping out—discard the contents immediately. Do not taste or consume spoiled canned goods.

Frequently Asked Questions

Can I can tomatoes without adding lemon juice?

No, it’s not recommended. Tomatoes are borderline acidic, and adding lemon juice or citric acid ensures the pH stays below 4.6, which is critical for preventing botulism. Even if your tomatoes seem acidic, it’s safer to add the acid.

How do I know if my canned tomatoes are safe to eat?

Check for proper seals (concave lids that don’t pop when pressed), no bulging or leaking, and no off odors or mold. If the jar is sealed and looks normal, it’s likely safe. When in doubt, throw it out.

Can I use vinegar instead of lemon juice for acidification?

Yes, you can use white vinegar (5% acidity) as a substitute. Use 2 tablespoons of vinegar per quart or 1 tablespoon per pint. However, vinegar may impart a slightly different flavor to your tomatoes.

What’s the difference between water bath and pressure canning?

Water bath canning uses boiling water to process high-acid foods like tomatoes with added acid. Pressure canning uses steam under pressure to reach higher temperatures (240°F) needed for low-acid foods like meats and vegetables. For tomatoes without added acid, pressure canning is required.

Can I can tomato sauce or paste using the same method?

Yes, but processing times may vary. Tomato sauce and paste are thicker and may require longer processing times. Always follow a tested recipe from a reliable source like the USDA or National Center for Home Food Preservation.

Final Thoughts

The best method for canning tomatoes depends on your tomatoes’ acidity and your equipment. Water bath canning is safe and simple for high-acid tomatoes with added lemon juice, while pressure canning is essential for low-acid varieties or mixtures. Proper preparation, processing, and storage ensure your canned tomatoes stay fresh and safe for up to 18 months.

With these steps, you can enjoy the taste of summer tomatoes year-round, whether in sauces, soups, or stews.