To can tomatoes safely, peel and core them, add 2 tablespoons of bottled lemon juice or 1/2 teaspoon of citric acid to each quart jar, pack them with 1/2 inch of headspace, and process in a boiling-water canner: 45 minutes for quarts and 40 for pints at 0–1,000 feet, longer at higher altitudes.
On this page
This is the tested procedure for whole or halved tomatoes packed in water from the National Center for Home Food Preservation (NCHFP), which publishes the USDA’s home canning guidance. Follow it exactly. Canning is one place where improvising isn’t safe: the times were worked out for this jar size, this pack and this acid level.
Why do you add lemon juice to canned tomatoes?
Tomatoes sit close to the line between acid and low-acid foods, and their acidity varies. The NCHFP says to add acid to whole, crushed or juiced tomatoes every time, and not to leave it out. That extra acid is what makes a boiling-water process safe for them.
| Acid | Per pint | Per quart |
|---|---|---|
| Bottled lemon or lime juice | 1 tablespoon | 2 tablespoons |
| Citric acid | 1/4 teaspoon | 1/2 teaspoon |
| Vinegar (5% acidity) | 2 tablespoons | 4 tablespoons |
Put the acid straight into the jars before filling them. The NCHFP notes that vinegar may cause undesirable flavor changes, and that you can add a little sugar to offset the sour taste if you like. Use bottled juice, not fresh: its acidity is consistent.
Which tomatoes can you use?
Choose disease-free, firm fruit, preferably vine-ripened. The NCHFP says do not can tomatoes from dead or frost-killed vines. Green tomatoes are more acidic than ripe ones and can be canned safely with the same procedure.
Plan on about 3 pounds per quart. The NCHFP estimates 21 pounds for a canner load of 7 quarts and 13 pounds for 9 pints; a 53-pound bushel yields 15 to 21 quarts.
Raw pack or hot pack?
Both are tested for this recipe and use the same processing times.
- Raw pack is faster: peeled tomatoes go straight into the jars and you cover them with boiling water.
- Hot pack means boiling the tomatoes gently for 5 minutes first. They shrink, so more fit in each jar and they float less.
Preheat the canner water to 140°F for raw pack and 180°F for hot pack, per the NCHFP’s canner instructions.
How does altitude change the processing time?
Water boils at a lower temperature the higher you live, so jars need longer in the canner. These are the NCHFP’s boiling-water times for whole or halved tomatoes packed in water, raw or hot pack:
| Jar size | 0–1,000 ft | 1,001–3,000 ft | 3,001–6,000 ft | Above 6,000 ft |
|---|---|---|---|---|
| Pints | 40 min | 45 min | 50 min | 55 min |
| Quarts | 45 min | 50 min | 55 min | 60 min |
Not sure of your elevation? Look it up before canning day; your county extension office can help. The NCHFP also publishes pressure-canner times for this product if you’d rather use one.
Safety: Use only tested instructions like these, unchanged. Always add the bottled lemon juice or citric acid. Do not use open-kettle canning (filling hot jars and just letting them seal) or process jars in an oven, microwave or dishwasher; the NCHFP says these methods don’t prevent spoilage, and jars in an oven can crack or explode. Use Mason-type canning jars and new lids every time. If a lid doesn’t seal within 24 hours, reprocess with a new lid, or refrigerate and eat within several days. Never taste food from a jar that is unsealed or shows signs of spoilage: a swollen or bulging lid, streaks of dried food down the jar, rising bubbles, unnatural color, liquid that spurts when opened, an off odor, or mold. The NCHFP notes that spoiled tomatoes may show very little evidence, and says to treat suspect jars as possibly containing botulinum toxin; follow its handling and disposal directions.
How do you know the jars sealed?
After the jars have cooled for 12 to 24 hours, remove the bands and test each lid. The NCHFP gives three checks:
- Press the center. If it springs up when you let go, it isn’t sealed.
- Tap it with a teaspoon. A clear ringing sound means sealed; a dull thud means it may not be.
- Look at it from the side. A sealed lid curves down slightly in the middle.
Wash and dry the sealed jars, label them, and store them without the bands so a failed seal is easy to spot. Keep them somewhere clean, cool, dark and dry. The NCHFP recommends 50–70°F and canning no more than you will use within a year.
Where canned tomatoes fit
A shelf of home-canned tomatoes is one of the most useful things in a from-scratch pantry: sauce, soup, chili and braises all start there. Buying tomatoes by the box from a local grower at the peak of the season and putting them up is also one of the most direct ways to keep money in your local food system. For storing them alongside dry goods, see long-term food storage for beginners, and for the rest of the pantry skills, the Pantry & From Scratch hub.
The recipe
How to Can Tomatoes (Whole or Halved, Water Bath)
- Prep1 hr
- Cook1 hr 15 min
- Total2 hr 15 min
- Makes7 quarts or 9 pints (about 21 pounds of tomatoes for 7 quarts, 13 pounds for 9 pints)
Ingredients
- About 21 pounds firm, ripe, disease-free tomatoes for 7 quarts (about 13 pounds for 9 pints)
- Bottled lemon juice: 2 tablespoons per quart jar or 1 tablespoon per pint jar (or citric acid: 1/2 teaspoon per quart, 1/4 teaspoon per pint)
- Salt (optional): up to 1 teaspoon per quart
- Water, for packing
- Mason-type canning jars, new lids and screw bands
Steps
- Wash jars and keep them hot. Prepare new lids according to the manufacturer's directions. Fill a boiling-water canner with the rack in place and preheat the water to 140°F for raw pack or 180°F for hot pack.
- Wash the tomatoes. Dip them in boiling water for 30 to 60 seconds, until the skins split, then dip them in cold water.
- Slip off the skins and remove the cores. Leave the tomatoes whole or cut them in half.
- Add bottled lemon juice or citric acid to each jar: 2 tablespoons lemon juice or 1/2 teaspoon citric acid per quart; 1 tablespoon or 1/4 teaspoon per pint. Add up to 1 teaspoon salt per quart, if desired.
- Raw pack: heat water to boiling. Fill the hot jars with raw tomatoes, leaving 1/2-inch headspace, then cover with boiling water, keeping 1/2-inch headspace. Hot pack: cover the tomatoes with water in a large pan, boil gently for 5 minutes, fill hot jars with the tomatoes, and add cooking liquid to cover, leaving 1/2-inch headspace.
- Remove air bubbles, adjust headspace if needed, and wipe the jar rims clean. Put on lids and screw bands.
- Load jars into the canner with a jar lifter. Add boiling water if needed so the water is at least 2 inches above the jar tops, since this process runs longer than 30 minutes.
- Cover the canner and heat on high until the water boils vigorously. Start timing: at 0-1,000 feet, 40 minutes for pints or 45 minutes for quarts. At higher altitude, use the table on this page. Keep a gentle but complete boil the whole time; if the boil stops, bring it back and start the timing over.
- Turn off the heat, remove the canner lid, and wait 5 minutes. Lift the jars out upright and set them on a towel with at least 1 inch between them.
- Let the jars cool undisturbed for 12 to 24 hours. Do not retighten the bands. Remove the bands, check the seals, label, and store in a cool, dark, dry place.
Questions people ask
Do you have to add lemon juice when canning tomatoes?
Yes. The National Center for Home Food Preservation says not to leave the acid out. Add 2 tablespoons of bottled lemon juice or 1/2 teaspoon of citric acid per quart, or 1 tablespoon or 1/4 teaspoon per pint.
Can I use fresh lemon juice instead of bottled?
No. The tested NCHFP procedure calls for bottled lemon or lime juice, which has a consistent acidity. Citric acid is the other approved option.
How long do you water bath tomatoes?
For whole or halved tomatoes packed in water, raw or hot pack: 40 minutes for pints and 45 minutes for quarts at 0–1,000 feet. Add 5 minutes for 1,001–3,000 feet, 10 for 3,001–6,000 feet and 15 above 6,000 feet.
Can I can tomatoes in the oven?
No. The NCHFP does not recommend oven canning or open-kettle canning. Neither reliably prevents spoilage, and jars heated in an oven can crack or break.
How long do home-canned tomatoes last?
For best quality, the NCHFP advises canning no more than you will use within a year and storing jars in a clean, cool, dark, dry place between 50 and 70°F.
Is it safe to add salt?
Salt is optional and only for flavor. The NCHFP procedure allows 1 teaspoon per quart if you want it.
Sources
- National Center for Home Food Preservation — Whole or Halved Tomatoes (Packed in Water)
- National Center for Home Food Preservation — Tomato Acidification Directions
- National Center for Home Food Preservation — Canning Tomatoes, Introduction
- National Center for Home Food Preservation — Using Boiling Water Canners
- National Center for Home Food Preservation — Cooling Jars and Testing Jar Seals
- National Center for Home Food Preservation — Equipment and Methods Not Recommended
- National Center for Home Food Preservation — Storing Home Canned Foods
- National Center for Home Food Preservation — Identifying and Handling Spoiled Canned Food