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Tomatoes and Salsa

Canning Tomato and Tomato Products? Pay Attention to Directions

By Suzanne Driessen, Extension Educator — Food Safety

August 2012

tomato canner with tomatoes and jars

Introduction

Home canning tomatoes is a great way to preserve them for later use. Proper methods, choice ingredients, and awareness of acidity levels are critical to a safe home-canned product.

The National Center for Home Food Preservation Canning Tomatoes and Tomato Products webpage lists over 15 options for home canning tomatoes.  There are directions for canning juice, paste, sauce, crushed tomatoes, tomatoes packed in water, tomatoes packed in juice, and tomatoes pack raw without added liquid and more. Each recipe has specific directions on preparing the tomatoes, filling the jars and processing time.  

Directions and processing times for tomatoes and tomato products were re-evaluated for safety in the late 1980’s. The updated directions were published in 1994 in the USDA Complete Guide to Home Canning. For safety sake, be sure to use a research tested recipe dated 1994 or newer. Be sure to select the recipe for the tomato product you are canning and follow all instructions exactly. 

Tips For a Safe and Tasty Home Canned Tomato Product

  • Always use the best quality of ingredients. Choose fresh, vine-ripened tomatoes that are at their peak ripeness. Over-ripe tomatoes are less acidic.
  • Tested recipes and methods use the best quality of tomatoes preserved. Diseased or bruised tomatoes may have extra pathogens. The process time may not be enough to kill extra organisms if a damaged or diseased tomato is used.
  • Tomatoes vary in acidity level 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.
  • It is important to add acid to all water bath and pressure canned tomato products to ensure a safe level of acidity which is at a pH of 4.6 or less (high acid level), to prevent the growth of C. Botulinum bacteria which causes botulism.
    • Added acid can be in the form of:
      • Citric acid (1/2 tsp/quart, ¼ tsp/pint). Canning supply companies like Mrs. Wages® and Ball® have a powder form. Some health food stores carry citric acid too; be sure it is food grade.
      • Lemon juice (2 Tbsp/quart, 1 Tbsp/pint). If using lemon juice, use commercially bottled juice as fresh lemons vary in acidity levels. You can safely use bottled lime juice instead of bottled lemon juice.
      • Vinegar 5% acidity (4 Tbsp/quart, 2 Tbsp/pint). Will result in noticeable flavor change. You can add a small amount of sugar to help offset the flavor.
  • Processing times are based on the type of liquid used to pack or fill the jar of tomatoes. Tomatoes with no added liquid or packed in tomato juice have longer processing times because the heat distribution is less effective in juice than in water.
  • Remember to adjust for Minnesota altitudes, choose processing times for 1001 – 2000 feet.
  • Processing times found on University of Minnesota’s Extension website are adjusted for Minnesota altitudes.

Tomatoes – Boiling Water Bath and/or Pressure Canner

Minnesota Home Canning Processing Chart

Processing times are based on the type of liquid used to pack or fill the jar of tomatoes. Tomatoes with no added liquid or packed in tomato juice have longer processing times because the heat distribution is less effective in juice than in water.
Note:  This chart is provided for experienced canners familiar with safe canning methods.  Time assumes a full 10 minute exhausting of the pressure canner.  Once pressure is raised to an accurate level and stabilized, timing begins according to chart.  For more complete canning instructions, refer to National Center for Home Food Preservation.

Type of Food

Style of Pack

Jar Size

Head Space

Boiling Water Bath

Pressure Canner

Dial Gauge

Weighted Gauge

Tomatoes*
(no added liquid)

Raw

Pints and
Quarts -

½ inch

90 minutes

25 minutes

11#

15#

Tomatoes*
(packed in water)

Hot and Raw

Pints -
Quarts -

½ inch
½ inch

45 minutes
50 minutes

10 minutes
10 minutes

11#
11#

15#
15#

Tomatoes*
(packed in juice)

Hot and Raw

Pints and
Quarts -

½ inch

90 minutes

25 minutes

11#

15#

Tomato Juice*

Hot

Pints -
Quarts -

½ inch
½ inch

40 minutes
45 minutes

15 minutes
15 minutes

11#
11#

15#
15#

* To ensure safe acidity in all canned tomato products, add bottled lemon juice or vinegar or citric acid directly to the jars before filling with product.

  • PINTS:  1 tablespoon bottled lemon juice OR 2 tablespoon vinegar OR ¼ teaspoon citric acid to each pint of tomatoes
  • QUARTS:  2 tablespoons bottled lemon juice OR 4 tablespoons vinegar OR ½ teaspoon citric acid to each quart of tomatoes

References

Photo courtesy of National Center for Home Preservation

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