Canning Tomatoes

HYG-5336
Family and Consumer Sciences
Date: 
05/28/2015
Revised by: Lisa Barlage, Extension Educator, Family and Consumer Sciences

Tomatoes are the most widely home canned product in the United States. Home canned tomatoes can be prepared in a ready-to-use, crushed format, or they may be left whole or halved. Whole or halved tomatoes may be canned by covering with water or tomato juice; they may also be canned with no added juice. Crushed tomatoes must be hot packed. It is very important to match the preparation process you have selected with the correct processing times from either Tables 2 or 3.

General Instructions

Selection

When canning, select only disease-free, preferably vine-ripened, firm fruit. Do not can tomatoes from dead or frost-killed vines. Unripened tomatoes are more acidic than ripened fruit and can be canned safely with any of the following recommendations. For best results, process tomatoes within 2 to 3 hours after harvest or purchasing. Canning whole cherry or grape tomatoes is not advised.

Acidification

Tomatoes have a pH between 4 and 4.6. To ensure safe acidity of whole, crushed or juiced tomatoes, use the recommendations in the chart below. Acidification is required when pressure canning or boiling water bathing tomatoes.

Table 1. Acidification Table
Acid* Pint Quart
Bottled Lemon Juice 1 tablespoon 2 tablespoons
Citric Acid ¼ teaspoon ½ teaspoon
Vinegar (5 percent acidity) 2 tablespoons 4 tablespoons
*Add acid directly to the jars before filling with tomatoes. If desired, add up to 1 tablespoon of sugar per quart to offset acidic taste. Vinegar may cause undesirable flavor changes.

Sodium

The use of salt is optional in all canned tomato products. Salt can be used for flavor or color protection.

Processing

Even though both boiling water bath and pressure processing times are given (see Tables 2 and 3), recent research shows that for some tomato products, pressure processing will result in a more nutritious and higher quality canned good. Recipes that specify pressure canning only may contain many low-acid ingredients and can be safely canned only in a pressure canner at the specified pressure.

Crushed Tomatoes (no added liquid)

About 22 pounds of tomatoes are needed per canner load of 7 quarts; 14 pounds are needed per canner load of 9 pints.

Wash tomatoes and dip in boiling water for 30 to 60 seconds or until skins split, then dip in cold water. Slip off skins and remove cores. Trim off any bruised or discolored portions and quarter.

In a large pot, quickly heat one-sixth of the tomato quarters. As tomatoes are added to the pot, crush them with a wooden mallet or spoon. This draws off some juice. Continue heating the tomatoes. Stir to prevent burning.

As soon as the tomatoes boil, gradually add the remaining quartered tomatoes. Stir constantly. The remaining tomatoes do not need to be crushed; they will soften with heating and stirring. Continue until all tomatoes are added. Boil gently for 5 minutes.

Add bottled lemon juice or citric acid to jars as listed in Table 1. If desired, add 1 teaspoon of salt to each quart jar, or ½ teaspoon to each pint. Fill jars immediately with hot tomatoes. Leave one-half inch of headspace. Adjust lids and process jars as described in Tables 2 or 3.

Whole or Halved Tomatoes

About 21 pounds of tomatoes are needed per canner load of 7 quarts; 13 pounds are needed per canner load of 9 pints.

Wash tomatoes. Dip in boiling water for 30 to 60 seconds or until skins split; then dip in cold water. Slip off skins and remove cores. Leave whole or halve.

Add bottled lemon juice or citric acid to jars as listed in Table 1. If desired, add 1 teaspoon of salt per quart, or ½ teaspoon to each pint.

Packe​d in Water

Hot Pack

Add enough water to cover the tomatoes, and then boil gently for 5 minutes. Fill jars with hot tomatoes. Add hot cooking liquid to cover leaving one-half inch of headspace. Adjust lids and process jars as described in Tables 2 or 3.

Raw Pack

Fill clean jars directly with raw, peeled tomatoes. Add hot water to cover, leaving one-half inch of headspace. Adjust lids and process jars as described in Tables 2 or 3.

Packed Raw Without Added Liquid

Fill jars with raw tomatoes, leaving one-half inch of headspace. Press tomatoes in the jars until spaces between them fill with juice. Leave one-half inch of headspace. Adjust lids and process jars as described in Tables 2 or 3.

Packed in Tomato Juice

Hot Pack

Put tomatoes in a large saucepan and add enough tomato juice to completely cover them. Boil tomatoes and juice gently for 5 minutes. Fill jars with hot tomatoes, leaving one-half inch of headspace. Add hot tomato juice to the jars to cover the tomatoes, leaving one-half inch of headspace. Adjust lids and process jars as described in Tables 2 or 3.

Raw Pack

Heat tomato juice in a saucepan. Fill jars with raw tomatoes, leaving one-half inch of headspace. Cover tomatoes in the jars with hot tomato juice, leaving one-half inch of headspace. Adjust lids and process jars as described in Tables 2 or 3.

Checking Seals and Storing

Listen for the familiar "ping" as the jars cool. Look for the slight depression in the lid's center. When completely cooled, test for proper seal by pushing down on center of lid; lid should not pop up and down. Allow the canned foods to cool on the counter top before removing the ringbands. Jars should not be stored with the ringbands on. After removing the ringbands, wipe jars with a clean, damp cloth to remove any residue or stickiness. Add labels with date, batch, food product and any other special information. Store jars in a cool, dry, dark place.

Table 2. Recommended Processing Times for Tomatoes in a Pressure Canner
Product Style of Pack Jar Size Process Time (in minutes) Canner Gauge Pressure (psi) at Different Altitudes (in pounds)
Dial Gauge Weighted Gauge
0–2,000 ft 0–1,000 ft 1,000+ ft
Crushed Tomatoes Hot Pints or quarts 15 11 lbs 10 lbs 15 lbs
Whole or Halved Tomatoes Packed in Water Hot or raw Pints or quarts 10 11 lbs 10 lbs 15 lbs
Whole or Halved Tomatoes Packed in Juice or Without Added Liquid Hot or raw Pints or quarts 25 11 lbs 10 lbs 15 lbs
Table 3. Recommended Processing Times for Tomatoes in a Boiling Water Canner
Product Style of Pack Jar Size Minutes of Processing at Different Altitudes
0–1,000 ft 1,000–3,000 ft
Crushed Tomatoes Hot Pints 35 40
Quarts 45 50
Whole or Halved Tomatoes Packed in Water Hot or raw Pints 40 45
Quarts 45 50
Whole or Halved Tomatoes Packed in Juice or Without Added Liquid Hot or raw Pints or quarts 85 90

References

Andress, E., and J. Harrison. So Easy to Preserve. 6th ed. Athens: University of Georgia Cooperative Extension Service, 2014.

United States Department of Agriculture. Complete Guide to Home Canning, Agriculture Information Bulletin No. 539. 2009.

Ohioline http://ohioline.osu.edu