A look at an historic mushroom text.
“In 1879 mushrooms were exported from Japan to the value of 243,440 yens. The yen is equal to 99.7 cents. Among the northeastern tribes of Asia fungi are largely used as food. One species, when pounded, forms their snuff, while another, the Fly Agaric, which is utilized in Europe as a fly killer, and is regarded as one of the most poisonous forms, is used by them as a substitute for ardent spirits. One large specimen is sufficient “to produce a pleasant intoxication for a whole day,” the alcohol being obtained by the usual method of fermentation. In many parts of Europe fungi are a favorite food, being eaten fresh, and also preserved in vinegar for winter use. For pickling purposes, all kinds, it is said, are gathered, the vinegar being supposed to neutralize the alkaline poison of the noxious species.”
What I find interesting about this passage from an 1894 US government publication on mushrooms is the weaving of fact and fiction. Amanita muscaria, known as the fly agaric due to its alleged fly killing properties, is on the one hand declared to be “one of the most poisonous forms” while at the same time the mushroom is described as a substitute for “ardent spirits.” The text elaborates that one specimen is enough to produce a “pleasant intoxication for whole day.” How can this circle be squared? The text is silent. But it goes on to link the mushroom’s intoxicating properties to it having been fermented in the “usual way”. This is the first time I have encountered a text that suggests that A. muscaria’s intoxicating properties are the product of fermentation! They are not. The idea itself is crazy! Mushrooms don’t have starch or sugars to ferment. The allegedly poisonous properties in the mushroom are intrinsic to the mushroom itself as is its ability to alter one’s mental state if eaten raw. Parboiling washes away the toxins that inebriate rendering the mushroom a delightful comestible.
The 19th century mushroom literature placed a great deal of reliance on vinegar as a mushroom detoxifying agent. You will note that the author distances himself from this idea while at the same time repeating it. Methods for detoxifying A. muscaria from the late 19th-century and early 20th-century called for both boiling in water and also macerating in vinegar. What is true is that some mushroom toxins are water-soluble and thus rinsed away in a pickling process that includes parboiling. The vinegar does nothing except improve the taste of the pickled mushroom and help preserve it.