Quantity: An average of 14-1/2 pounds is neeed 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 following the recommedations in Table 1 or Table 2 according to the method of canning used.
| Table 1. Recommended process time for Mushrooms in a dial-gauge pressure canner. |
| | Canner Pressure (PSI) at Altitudes of |
| Style of Pack | Jar Size | Process Time | 0 - 2,000 ft | 2,001 - 4,000 ft | 4,001 - 6,000 ft | 6,001 - 8,000 ft |
| Hot | Half-pints or Pints | 45 min | 11 lb | 12 lb | 13 lb | 14 lb |
| Table 2. Recommended process time for Mushrooms in a weighted-gauge pressure canner. |
| | Canner Pressure (PSI) at Altitudes of |
| Style of Pack | Jar Size | Process Time | 0 - 1,000 ft | Above 1,000 ft |
| Hot | Half-pints or Pints | 45 min | 10 lb | 15 lb |