Canning Whole or Sliced Mushrooms
Mushrooms must be canned in a pressure canner for the correct time and pressure (PSI) to ensure their safety. If not canned correctly, these low acid foods may contain the deadly botulism toxin.
Vegetables may be canned without salt. Salt adds flavor but does not prevent spoilage. If you use a weighted-gauge canner and can at an altitude less than 1000 feet, you may use 10 PSI instead of 15 PSI for the canner pressure. This will improve nutrient and quality retention of the vegetables. Check with your local county extension office or Soil Conservation District for altitude information.
Quantity: An average of 14-1/2 pounds is needed per canner load of 9 pints; an average of 7-1/2 pounds is needed per canner load of 9 half-pints – an average of 2 pounds per pint.
Quality: Select only brightly colored, small to medium-size domestic mushrooms with short stems, tight veils (unopened caps), and no discoloration. Caution: Do not can wild mushrooms.
Procedure: Trim stems and discolored parts. Soak in cold water for 10 minutes to remove dirt. Wash in clean water. Leave small mushrooms whole; cut large ones. Cover with water in a saucepan and boil 5 minutes. Fill jars with hot mushrooms, leaving 1 inch headspace. Add 1/2 teaspoon of salt per pint to the jar, if desired. For better color, add 1/8 teaspoon of ascorbic acid powder, or a 500-milligram tablet of vitamin C. Add fresh hot water, leaving 1 inch headspace. Adjust lids and process.
Process Times and Methods (Half-pints & pints only)
1) Dial-gauge Pressure Canner
Half-pints or Pints – 45 minutes 11 PSI
2) Weighted-gauge Pressure Canner
Half-pints or Pints – 45 minutes 15 PSI