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Canning tomatoes: whole, half and juice

Jars of home canned tomatoes.

When canning tomatoes, begin with high-quality tomatoes and always add acid to your tomatoes before processing. Follow the directions below for canning whole or halved tomatoes and tomato juice. For more information, review our Safety guidelines for canning tomato products before canning. 

Choose only high-quality tomatoes

Choose fresh, vine-ripened tomatoes that are at their peak ripeness. Over-ripe tomatoes are less acidic. The acidity level in tomatoes varies throughout the growing season. Tomatoes reach their highest acidity when they are still green and decrease in acidity until they reach their lowest acidity as they mature.

Canning is NOT a way to use damaged tomatoes or those from dead or frost-killed vines. These tomatoes may have extra pathogens. The canning process time may not be enough to kill extra organisms. This could lead to a product that spoils and is unsafe to eat. 

Add acid to all tomatoes before processing

A high acid level (pH of 4.6 or less) prevents the growth of Clostridium botulinum bacteria which causes botulism. Because many factors impact the acidity level of tomatoes, USDA recommends adding acid to all home-canned tomatoes and tomato products.

Treat heirloom tomato varieties that same. The acidity of heirloom tomato plants is no different from the non-heirloom varieties. Some heirloom varieties are more low-acid than hybrid varieties. Therefore, the same acidification recommendations apply for canning heirloom tomatoes.

Amount of different acids to add to tomatoes

How different types of acid affect flavor and the amount to use.
Acid Affect Amount
Citric acid Little change in flavor 1/2 teaspoon per quart; 1/4 teaspoon per pint
Bottled lemon juice Easy to use 2 tablespoons per quart; 1 tablespoon per pint
Vinegar (5% acidity) Noticeable flavor change 4 tablespoons per quart; 2 tablespoons per pint

Canning whole or halved tomatoes (packed raw without added liquid)

Quantity

  • 21 pounds (average) yields a canner load of 7 quarts.
  • 13 pounds (average) yields a canner load of 9 pints.
  • 53 pounds (1 bushel) yields 15 to 21 quarts or 3 pounds (average) per quart.

Equipment

  • Large pot of boiling water for removing tomato skins.
  • Large container of ice-cold water.
  • Canning equipment (see Home canning basics).

Procedure

  • Wash tomatoes.
  • To remove skins: Dip in boiling water for 30 to 60 seconds or until skins split, then dip in cold water; skins should slide off easily.
  • Remove cores and leave whole or cut in half.
  • Add additional acid to jars according to the acidification chart above.
  • Add 1 teaspoon salt per quart to the jars, if desired.
  • Fill jars with raw tomatoes, leaving ½ inch headspace.
  • Press tomatoes in the jars until spaces between them fill with juice.
  • Leave ½ inch headspace.
  • Adjust lids and process.

Processing times by method

  • Boiling-water bath: pints or quarts – 90 minutes.
  • Dial-gauge pressure canner: pints or quarts – 25 minutes at 11 PSI or 40 minutes at 6 PSI.
  • Weight-gauge pressure canner: pints or quarts – 25 minutes at 15 PSI or 40 minutes at 10 PSI.

The National Center for Home Food Preservation has over 30 tomato product canning recipes. Choose processing times and methods for Minnesota altitudes of 1001-2000 feet.

Note: Processing times and pressures in this publication are for Minnesota altitude ranges.

Cooking tomatoes for juice.

Canning tomato juice

Quantity

  • 23 pounds (average) yields a canner load of 7 quarts.
  • 14 pounds (average) yields a canner load of 9 pints.
  • 53 pounds (1 bushel) yields 15 to 18 quarts or 3¼ pounds (average) per quart.

Procedure

  • Wash, remove stems and trim off bruised or discolored portions.
  • To prevent juice from separating, quickly cut about 1 pound of fruit into quarters and put directly into saucepan.
  • Heat immediately to boiling while crushing.
  • Continue to slowly add and crush freshly cut tomato quarters to the boiling mixture; make sure the mixture boils constantly and vigorously while you add the remaining tomatoes.
  • Simmer 5 minutes after you add all pieces.
  • If you are not concerned about juice separation, simply slice or quarter tomatoes into a large saucepan; crush, heat and simmer for 5 minutes before juicing.
  • Press heated juice through a sieve or food-mill to remove skins and seeds.
  • Heat juice again to boiling.
  • Add additional acid to jars according to the acidification chart above.
  • Add 1 teaspoon salt per quart to the jars, if desired.
  • Fill jars with hot tomato juice, leaving ½ inch headspace.
  • Adjust lids and process.

Processing times by method

  • Boiling-water bath: pints – 40 minutes; quarts – 45 minutes.
  • Dial-gauge pressure canner: pints or quarts – 15 minutes at 11 PSI or 20 minutes at 6 PSI.
  • Weight-gauge pressure canner: pints or quarts – 15 minutes at 15 PSI or 20 minutes at 10 PSI.

Note: Processing times and pressures in this publication are for Minnesota altitude ranges.

William Schafer, emeritus Extension specialist and Suzanne Driessen, Extension educator

Reviewed in 2018

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