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.
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Dried Mushrooms
Wild mushrooms should be dried as soon as gathered; cultivated mushrooms will stand delay much better. Remove the stems and peel the caps; break the stems apart lengthwise, if thick. Set on agate or earthen plates over the range or in the sun. Cover, meanwhile, with coarse cheesecloth raised above the mushrooms.
Stir frequently. The mushrooms will be thoroughly dried in twenty-four hours.
Scald in a moderately cool oven before storing, also heat very hot at the start if the weather be hot and damp. The oven should not be hot enough to discolor the vegetables in the least, either at start or finish. Heating at first is to obviate all liability of souring. Heating the vegetables when dry is to sterilize and remove danger from germs that may have settled on the articles during drying.
A sound drying method that predates electric dehydrators, with one assumption worth correcting: the final oven pass is not a sterilization step in any meaningful sense.
- Identification firstThe recipe assumes a gatherer who already knows what is in the basket. Drying concentrates a toxic mushroom exactly as it concentrates an edible one, and no amount of heat neutralizes amatoxins. Only dry wild mushrooms you have identified with certainty.
- Agate plates"Agate" is speckled enamelled steelware, common in American kitchens of this period. Any non-reactive tray works — parchment-lined sheet pans, or the mesh trays of a dehydrator.
- Oven temperaturesThe book gives no figure for a "moderately cool oven"; read it as a low oven, and let the instruction not to discolor the mushrooms in the least be the real guide. A modern dehydrator at 125-135F does the whole job in 6-12 hours without any oven stage.
- Skip the peelingPeeling caps was standard practice when field mushrooms arrived gritty and the cuticle was thought indigestible. Today a dry brush is enough; the skin carries flavor and the cut surfaces dry faster if you slice rather than peel.
- Slice for speedThe original leaves caps whole and only splits thick stems. Cutting caps into 1/4-inch slices cuts drying time by more than half and makes the cracker-dry test easy to judge.
- What "thoroughly dried" meansA finished slice snaps rather than bends. Anything leathery still holds moisture and will mold in the jar. Twenty-four hours is optimistic for whole caps in humid weather.
- The sterilizing claimA brief warm oven does not sterilize. Dried mushrooms keep because their water activity is too low for spoilage organisms, not because they were heat-treated. Cool them completely, then store airtight in the dark; condensation in a warm-packed jar is the usual cause of failure.
- Never store in oilA modern hazard the book could not have known: dried mushrooms packed in oil at room temperature are a recognized botulism risk. Keep them dry.
- Yield and useRoughly ten pounds of fresh mushrooms reduce to about one pound dried. Rehydrate in hot water for 20-30 minutes and strain the soaking liquid through cloth before using it — it is the best part.
This book belongs to the era when home preserving was being rewritten as applied science: the "germs that may have settled on the articles during drying" is the language of a kitchen that had recently absorbed bacteriology and was applying it, sometimes over-enthusiastically, to techniques thousands of years old. Drying is the oldest way of keeping fungi, and much of Europe ran on it — Polish and Russian cooks dried boletes on strings above the stove, Italians did the same with porcini — because mushrooms flush all at once and rot within days. The distinction between wild mushrooms, which must be dried immediately, and cultivated ones, which can wait, reflects a period when commercial mushroom growing was established in the United States but field-gathered specimens still reached many kitchens. The insistence on not discoloring the caps is a flavor judgment, not a safety one: scorched mushrooms turn bitter and lose the savory character that is the whole point of drying them.