Apple butter, tested canning method
Apple butter is a smooth, concentrated apple preserve cooked with cider, vinegar, two sugars and spices, then hot-filled and processed in a boiling-water canner using the published jar-size and elevation schedule.
Pressure-canned mushrooms
Pressure canning of the specified domestic mushrooms · Home pressure-canned whole or sliced mushrooms
Whole or sliced domestic mushrooms packed hot in jars with fresh water and processed in a pressure canner, the tested home method for a low-acid vegetable.
Overview
Pressure-canned mushrooms are domestic mushrooms packed hot into jars with fresh water and processed in a pressure canner. Mushrooms are a low-acid vegetable, so the water-bath method used for acidified products does not make them safe; the process needs the pressure canner and its time.
This entry covers the tested home method for whole or sliced domestic mushrooms. It is a method description, not a preserved-food tradition.
Method
Mushrooms are chosen small to medium, with short stems, closed caps and bright colour. Stems and discoloured parts are trimmed, and the mushrooms are soaked in cold water for 10 minutes and washed. Small mushrooms are left whole and large ones are cut. They are boiled in water for 5 minutes, packed hot into jars, and covered with fresh hot water, leaving 1 inch of headspace in each case.
Salt and a colour agent are optional. Half a teaspoon of salt per pint and an eighth of a teaspoon of ascorbic acid powder, or one 500 mg vitamin C tablet, are the stated amounts.
Process and altitude
The source gives a 45-minute process at pressure for hot-packed half-pint or pint jars. The pressure depends on the gauge: a dial-gauge canner runs at 11 lb from sea level to 2,000 ft, 12 lb to 4,000 ft, 13 lb to 6,000 ft and 14 lb to 8,000 ft; a weighted-gauge canner runs at 10 lb up to 1,000 ft and 15 lb above that.
The procedure asks the cook to read the NCHFP guidance on pressure canners and the principles of home canning before a first attempt.
Scope and limits
The source excludes wild mushrooms in the same sentence that sets out the procedure. It gives no quart times, no raw-pack method and no brine ratio, so those are not offered here.
Oregon State University Extension scopes its home-canning advice to domestically cultivated button mushrooms. Other species, purees, pates and different jar sizes or pack densities are outside the tested procedure.
Appearance, smell and taste cannot show that a sealed jar is safe. The source gives no storage duration, and none is stated here.
Ingredients
Yield 9 half-pint jars or pints per canner load · Scaling: use the stated load sizes; the source gives no quart times and no raw pack method.
Small to medium domestic mushrooms, short stems, closed capsTrim stems and discoloured parts; soak in cold water for 10 minutes, wash, leave small mushrooms whole and cut large ones
2 lb per pint
About 14-1/2 lb per 9-pint load or 7-1/2 lb per 9-half-pint loadSalt (optional)
½ tsp per pint
OptionalAscorbic acid powder (optional)
0.6 mL⅛ tsp as recorded
Optional colour agent, or one 500 mg vitamin C tabletFresh hot waterAdded to the jars; no brine ratio is given
Amount not stated
Method
Risks and precautions · High risk
Low-acid vegetable in jars
Mushrooms are low-acid, so the botulism risk is controlled only by a full pressure-canning process.
Hazard sourceWild mushrooms
The source states: Do not can wild mushrooms.
Hazard sourcePressure canner at the stated pressure for the altitude and gauge type, 45 minutes process time for hot-packed half-pints or pints
Control sourceDo not can wild mushrooms.
The source does not cover quart jars, raw packing or brine recipes; use a current tested source for those.
Purees, pates, other species and other pack densities cannot be substituted without validation.
- Trim stems and discoloured parts, soak the mushrooms in cold water for 10 minutes, and wash them in clean water.
- Leave small mushrooms whole and cut large ones. Cover with water in a saucepan and boil for 5 minutes.
- Fill hot half-pint or pint jars with the hot mushrooms, leaving 1 inch of headspace.
- Add salt and or colour agent if wanted, then add fresh hot water, leaving 1 inch of headspace.
- Adjust lids and process in a pressure canner for 45 minutes at the pressure set for the altitude and the gauge type: dial gauge 11 lb at 0 to 2,000 ft, 12 lb at 2,001 to 4,000 ft, 13 lb at 4,001 to 6,000 ft, 14 lb at 6,001 to 8,000 ft; weighted gauge 10 lb at 0 to 1,000 ft and 15 lb above 1,000 ft.
Conditions
Yield9 half-pint jars or pints per canner load
Places
United States
Documented preparation · Country evidenceTested home-preservation procedure from the National Center for Home Food Preservation; a country-level source, not a precise origin.
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Sources
National Center for Home Food PreservationMethod · Safety
Mushrooms, Whole or Sliced: Home Pressure CanningHot pack, 1 inch headspace, 45 minutes at pressure by gauge and elevation; wild mushrooms excluded
Oregon State University ExtensionMethod
Preserving Mushrooms (SP 50-919)Home-canning scope: domestically cultivated button mushrooms