Important: Safety Warning
This page offers rules for telling edible mushrooms from poisonous ones. No such rules are reliable, and these identifications predate modern mycology. Deadly species closely resemble edible ones, and mistakes are regularly fatal. Never eat a wild mushroom on the strength of this text.
This information has been left in for historical purposes but should not be acted upon.
Mushrooms, Pickled
INGREDIENTS. - Sufficient vinegar to cover the mushrooms; to each quart of mushrooms, 2 blades of pounded mace, 1 oz. of ground pepper, salt to taste.
Choose some nice young button mushrooms for pickling and rub off the skin with a piece of flannel and salt and cut off the stalks; if very large, take out the red inside and reject the black ones, as they are too old. Put them into a stewpan, sprinkle salt over them, with pounded mace and pepper in the above proportion; shake them well over a clear fire until the liquor flows and keep them there until they are all dried up again; then add as much vinegar as will cover them; just let it simmer for 1 minute and store it away in stone jars for use. When cold, tie down with bladder and keep in a dry place: they will remain good for a length of time and are generally considered delicious.
SEASONABLE. - Make this the same time as ketchup, from the beginning of September to the middle of October.
This is a genuine recipe, but it is a room-temperature anaerobic preserve of a low-acid vegetable with no measured acid and no processing step. The specific hazards are below.
- The acid is never measured"Sufficient vinegar to cover" gives no way to know the finished acidity, and the mushrooms have just been sweated so they carry their own liquor into the jar. Safe vinegar pickling depends on a known ratio of acid to food, not on the appearance of the surface.
- Mushrooms are a low-acid foodFungi sit around pH 6 and pack densely under liquid, which is close to ideal for Clostridium botulinum. Improperly acidified home-preserved mushrooms are one of the better documented vehicles for botulism, and the toxin gives no smell, taste or visible sign.
- One minute of simmering is not a processA brief simmer kills spoilage yeasts and moulds but does nothing to botulinum spores. The result is a sealed, oxygen-poor jar held at room temperature, in which the surviving spores have no competition.
- The bladder sealTying down with softened bladder was the standard Victorian closure: it shrank as it dried and sealed the jar mouth tightly. It excludes air without sterilising anything, which is exactly the wrong combination here.
- "Keep good for a length of time""They will remain good for a length of time" -- The recipe expects long storage in a dry place. Nothing in the method supports shelf stability, and the intended keeping period is the point at which risk is highest.
- The mushrooms themselvesThe instructions to reject the black ones and cut out the red interior assume mushrooms of mixed maturity, as gathered field mushrooms would be; the recipe does not say whether they are picked or bought.
- If you want pickled mushroomsUse a current tested recipe from a food-preservation authority, with specified vinegar strength and a specified process. Do not adapt this one.
Pickled mushrooms belong to the same autumn ritual as mushroom ketchup, which is why Mrs Beeton dates both to the beginning of September through mid-October: that is the English field-mushroom season, and a household that had gathered more than it could eat fresh turned the surplus into vinegar pickles and dark, salty ketchups to season winter cooking. The pounded mace and heavy hand with ground pepper are typical of nineteenth-century British preserving, where spice served as flavouring and, it was believed, as a keeping agent. Bladder — a cleaned animal bladder soaked soft, stretched over the jar mouth and tied — was the ordinary domestic closure before screw-top glass and rubber rings became cheap, and its disappearance from kitchens is a fair marker of how much preserving practice changed between Beeton's day and the arrival of tested, measured canning guidance in the twentieth century.