If this is your first time canning or it has been awhile, it is recommended that you read Using Pressure Canners and General Canning Information before beginning.
2. Ingredients
- 14 1/2 pounds mushrooms (makes 9 pints)
- Canning and pickling salt (1/2 teaspoon per pint/1 teaspoon per quart)--optional
- 1/8 teaspoon of ascorbic acid powder or a 500-milligram tablet of vitamin C (per pint)--optional, for better color
3. Equipment
- Pressure canner: A specially-made heavy pot with a rack and a lid that can be closed tightly to prevent steam from escaping. The lid is fitted with a vent (or petcock), a dial or weighted pressure gauge and built-in safety features. It must be large enough to hold at least four quart-size jars.
- Canning jars: Use standard canning jars without cracks or chips (see recipe for sizes)
- Caution: Quart jars are NOT recommended due to the denseness of the canned product.
- Lids and bands: Bands can be reused if they are in good shape, but lids must be new to ensure a proper seal
- Long-handled spoon
- Wide-mouth funnel
- Jar lifter (for moving jars into/out of canner)
- Lid wand (magnetic tool used to transfer lids to jars)
- Bubble freer, or a plastic or rubber knife-like utensil
- Ruler for measuring headspace (some bubble freers include this feature)
- Large covered cooking pot
- Medium pot for extra boiling water
- Bowl to soak mushrooms
- Towels or wire rack for cooling jars
- Paper towels
- Hot pads
- Cutting board
- Knives
- Food thermometer for measuring temperature of processing water
- Timer or clock
4. Prepare Canning Equipment
Pressure Canner-
- Assemble and wash equipment and containers.
- Wash canning jars in soapy water, rinse, and keep hot. (This can be done in a dishwasher or by placing jars in the water that is heating in your canner.)
- Follow manufacturer’s instructions for preparing lids.
- Put the rack and hot water into the canner. If the amount of water is not specified for a given food, use enough water so it is 2 to 3 inches high in the canner. (Always follow the directions with USDA processes for specific foods if they require more water be added to the canner.)
- For hot packed foods, you can bring the water to 180 degrees F ahead of time, but be careful not to boil the water or heat it long enough for the depth to decrease.
- For raw packed foods, the water should only be brought to 140 degrees F.
- Begin preparing food for your jars while this water is preheating.
5. Prepare Ingredients
- 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 mushrooms in pan with water in a saucepan and boil 5 minutes.
- In a medium cooking pot, boil water to be used to cover mushrooms before adding lids.
6. Pack Jars
Hot Pack-
- 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 per pint jar.
- Add boiling water, maintaining 1-inch headspace.
- Remove air bubbles.
- Add additional boiling water, if needed, leaving 1-inch headspace.
- Wipe jar rims with clean, wet paper towel.
- Place lid on jar and add screw band. Screw the band down fingertip tight- not too loose nor too tight. Follow lid manufacturer's directions for tightening the jar lids properly.
7. Process Jars
Pressure Canner-
- Place filled jars, fitted with lids and ring bands, on the jar rack in the canner, using a jar lifter. When moving jars with a jar lifter, make sure the jar lifter is securely-positioned below the neck of the jar (below the ring band of the lid). Keep the jar upright at all times since tilting the jar can cause food to spill into the sealing area of the lid.
- Fasten the canner lid securely. Leave the weight off the vent pipe or open the petcock.
- Turn the heat setting to its highest position. Heat until the water boils and steam flows freely in a funnel-shape from the open vent pipe or petcock. While maintaining the high heat setting, let the steam flow (exhaust) continuously for 10 minutes.
- After this venting, or exhausting, of the canner, place the counterweight or weighted gauge on the vent pipe, or close the petcock. The canner will pressurize during the next 3 to 10 minutes.
- Refer to the tables below for the correct pressure and processing times for your elevation, gauge type and jar size.
- Start timing the canning process when the pressure reading on the dial gauge indicates that the recommended pressure for your elevation has been reached, or when the weighted gauge begins to jiggle or rock.
- One type of weighted gauge should jiggle a certain number of times per minute, while another type should rock slowly throughout the process – check the manufacturer’s directions!
- Regulate heat under the canner to maintain a steady pressure at or slightly above the correct gauge pressure.
IMPORTANT: If at any time pressure goes below the recommended amount, bring the canner back to pressure and begin the timing of the process over, from the beginning (using the total original process time). This is important for the safety of the food because loss of pressure at any time can result in under-processing, or unsafe food and quick and large pressure variations during processing may cause unnecessary liquid losses from jars.
- When the timed process is completed, turn off the heat, remove the canner from the heat (electric burner) if possible, and let the canner cool down naturally. (Lift the canner to move it; do not slide the canner. It is also okay to leave the canner in place after you have turned off the burner. It is better to do so than to let jars inside the canner tilt or tip over if the canner is too heavy to move easily.)
- While the canner is cooling, it is also de-pressurizing. Do not force cool the canner. Forced cooling may result in food spoilage. Cooling the canner with cold running water or opening the vent pipe before the canner is fully depressurized are types of forced cooling. They will also cause loss of liquid from jars and seal failures. Forced cooling may also warp the canner lid.
- Even after a dial gauge canner has cooled until the dial reads zero pounds pressure, be cautious in removing the weight from the vent pipe. Tilt the weight slightly to make sure no steam escapes before pulling it all the way off. Newer canners will also have a cover lock in the lid or handle that must release after cooling before the lids are twisted off. Do not force the lid open if the cover locks are not released. Manufacturers will provide more detailed instructions for particular models.
- Depressurization of older canner models without dial gauges should be timed. Standard size heavy-walled canners require about 30 minutes when loaded with pints and 45 minutes when loaded with quarts. Newer thin-walled canners cool more rapidly and are equipped with vent locks that are designed to open when the pressure is gone. These canners are depressurized when the piston in the vent lock drops to a normal position. Some of these locks are hidden in handles and cannot be seen; however, the lid will not turn open until the lock is released.
- After the canner is completely depressurized, remove the weight from the vent pipe or open the petcock. Wait 10 minutes; then unfasten the lid and remove it carefully. Lift the lid with the underside away from you so that the steam coming out of the canner does not burn your face.
- Using a jar lifter, remove the jars one at a time, being careful not to tilt the jars. Carefully place them directly onto a towel or cake cooling rack, leaving at least one inch of space between the jars during cooling. Avoid placing the jars on a cold surface or in a cold draft.
- Let the jars sit undisturbed while they cool, for 12 to 24 hours. Do not tighten ring bands on the lids or push down on the center of the flat metal lid until the jar is completely cooled.
- Once cool, remove the screw bands and check the seal. If any jars did not seal, treat the food as 'fresh' by:
- Eating the food immediately
- Refrigerating for use within a week
- Freezing
- Recanning (If recanned, you must repeat the entire process.)
8. Store
- Wipe the jars clean and label with the date and processing method.
- Store in a cool, dark place, where there is no danger of freezing.
- Before tasting or serving, boil all home-canned, low-acid vegetables for a full 10 minutes at elevations below 1,000 feet. For elevations above 1,000 feet, add an additional minute of boiling time for each additional 1,000 feet. (Ex. at 5,000 feet boil for 15 minutes)
Not sure of your elevation? Click here
Dial gauge pressure canner-Process PINTS for 45 minutes
| 0-2,000 ft |
2,000-4,000 ft |
4,001-6,000 ft |
6,001-8,000 ft |
8,001-10,000 ft |
| 11 lbs |
12 lbs |
13 lbs |
14 lbs |
15 lbs |
Dial gauge pressure canner-Process QUARTS
Weighted gauge pressure canner-Process PINTS for 45 minutes
| 0-1,000 ft |
1,001-10,000 ft |
| 10 lbs |
15 lbs |
Weighted gauge pressure canner-Process QUARTS