a term of uncertain derivation, first recorded as an English word in the 9th century; it seems likely to have come from mousseron, a French term which nowadays applies only to various small mushrooms. The Grete Herbal of 1526 said of ‘mussherons’ that: ‘There be two maners of them, one maner is deedly and sleath them that eateth of them and be called tode stoles.’ Thus at that time mushroom was, as now, a wide meaning and could embrace toadstools too.
Scientists now use ‘mushroom’ in the strict sense to denote only the fruiting body of a fungus of either the order Agaricales (in which falls the common field mushroom and others—see agaric) or the order Boletales (in which the cep or king bolete is best known). But in everyday usage the word can be used very generally, applying to any edible fungi; and is certainly taken to include any edible fungus of the same general shape as a mushroom proper, having a round cap and usually a stalk. Some kinds of mushroom which grow out of the side of a tree trunk have almost no stalk. For example the oyster fungus, often called the oyster mushroom, has a very short, offset stem. And there are also stemless fungi attached directly to a tree trunk and known collectively as bracket fungi. But even these can be called mushrooms. Any fungus of obviously non-mushroom shape, such as the puffball, morel, or truffle, is usually referred to under its own name; but the general remarks on mushrooms here refer to these equally.
Mushrooms and other large varieties of fungus have been eaten since earliest times, as traces of puffballs in the prehistoric lake dwellings of Switzerland, Germany, and Austria show; but not by everyone and not everywhere.
The rarest and finest mushrooms, such as the truffle and the oronge, were highly esteemed in classical Greece and Rome, and have always been expensive. Some mushrooms are still among the most costly of foods, more expensive weight for weight than any of the spices except saffron. Cultivation, now under way for 300 years, has ensured that mushrooms are a common urban food as well as a feature of rural diet.
It is, however, easy to muster opinions hostile to mushrooms. To take examples from English only, Gerard, in his Herbal (1633), declared that ‘Most of them do suffocate and strangle the eater.’ Venner (Via Recta ad Vitam Longam, 1620) was only slightly less admonitory. ‘Many phantasticall people doe greatly delight to eat of the earthly excrescences called Mushrums. They are convenient for no season, age or temperament.’ And John Farley (The London Art of Cookery, 1784) referred to them as ‘treacherous gratifications’, emphasizing the need ‘that those employed in collecting them should be extremely cautious’.
The knowledge that some mushrooms are highly poisonous, accompanied by a vague and justified impression that old wives' rules of thumb for telling the safe ones apart from the dangerous are not to be trusted, probably accounts for the persistence of these negative impressions. But there may also be an element of fear of the supernatural at work. Mushrooms and truffles are indeed mysterious things, as explained under hallucinogenic mushrooms and toadstool. Their ephemeral nature, exemplified by the ink cap, and their apparent lack of roots lend credence to the idea that they are ‘unnatural’.
Wild mushrooms grow in most parts of the world and form part of the diet of most peoples, being eagerly gathered in most countries where they occur. The inhabitants of the British Isles, in company with the Dutch and most Arabs, are exceptions. British woods, and fields in the less intensively farmed regions, have plenty of varied and delicious fungi. But most British people recognize only the field mushrooms as edible and shun other species as ‘toadstools’. This tendency is even more noticeable in Ireland, where large crops of precious morels may go unharvested. The Russians, Scandinavians, and Swiss, in contrast, all gather wild mushrooms with great enthusiasm, thronging the woods every autumn.
On the whole, the best varieties of mushroom grow in wooded areas, whether deciduous, as for the cep and grisette, or coniferous, as for chanterelles and the Japanese matsutake and some kinds of boletus.
In the world of plants generally, it is common for a species to occur in only one region, with related but different species in other regions. Species of mushroom tend to have a wider distribution, no doubt because their spores are so tiny and light that they can be carried from one continent to another, by the wind or on birds' feet. For example, one common variety of cep, Boletus reticulatus, occurs in Europe, N. America, Japan, and Australia. It does, however, seem to be true that the northern hemisphere is richer in fungi than the southern.
Most mushrooms are edible, but only a small proportion are worth eating; the rest are tasteless or unpleasant. A few are indigestible enough to cause stomach aches, especially if eaten raw. And a very few are toxic, even fatally so. See the Warning below.
Mushrooms are not very nutritious in terms of energy value, since they are about 90% water, very low in fat, and have most of their carbohydrates in the form of indigestible chitin. But they do contain useful protein (1–3% depending on the species), and vitamins of the B group and certain others. For example, cultivated mushrooms have a little of vitamins C and K. The chanterelle owes its yellow colour to carotene, which yields vitamin A, and also contains vitamin D.
The Chinese, as is their wont, consider some mushrooms to be aphrodisiacs. But neither they nor anyone else seem to have speculated on the possibility that by eating mushrooms one might somehow absorb their remarkable physical force. Tales of paving stones caused to rise from their bed by a few small mushrooms are familiar. An experience which befell Sir Joseph Banks in the 18th century was even more dramatic. He left a cask of wine in his cellar for some years. Returning, he found that a fungal growth proceeding from the wine had completely filled the cellar and had become so hard that it had to be hacked away with an axe; and that the cask, now empty of wine, was firmly pinned against the ceiling by it.
The poor keeping quality of most fresh mushrooms has given rise to various methods of preserving them. They may be pickled or brined, canned, or made into ketchup, but the most usual way is to dry them. Strong-flavoured species preserve their taste remarkably well, and last for years if kept away from damp. The Chinese wood ear and the Japanese shiitake are both dried on a large scale. In Europe the most favoured species is the common cep: German dried Steinpilze and Italian funghi porcini are both the common cep.
Mushrooms shrink greatly when dried, so the flavour is concentrated. They may be added direct to soups and stews, or first soaked in water if they are to be used in dishes which cook quickly. A few dried ceps are an effective means of adding flavour to cultivated mushrooms.
Many people peel mushrooms before using them. However, a wash, after which the mushrooms are to be shaken free of excess moisture, is less wasteful; and most mushrooms are better not washed at all but simply brushed clean.
The chief risk in cooking fresh mushrooms is of overcooking them, so that they become unduly limp. True Agaricus mushrooms need very little cooking: indeed, they are excellent raw, in salads. The tougher species such as chanterelles are best braised very gently until just softened.
Warning Toxic mushrooms exist in many genera which include well-known edible species. Thus the blewit, cep, and even the common field mushroom have harmful relations. There is therefore some danger for amateurs in mushroom-gathering; but mushroom poisoning is, fortunately, rare. Most countries operate rigid controls over what may be sold in markets where wild mushrooms are offered. Anything which could even be confused with a toxic species is banned. Some countries even insist that there should be an inspection of mushrooms which amateurs have picked for their own use. One such is Norway, where there is a ‘sopkontrol’ (mushroom checkpoint) at Holmenkollen railway station in the hills above Oslo, a favourite place for gatherers.
The most notorious toxic species belong to the genus Amanita, which includes the terrible death cap (as well as the edible and excellent oronge, grisette, and blusher); but there are others, including a small parasol mushroom, and several of the numerous cobweb-caps.
Certain species, in addition to being mildly toxic, induce hallucinations. The best known of these is the fly agaric, the familiar white-spotted red toadstool of fairy pictures.
The amateur mushroom gatherer should eschew any mushroom which cannot be positively identified as belonging to a safe species. The risk of trouble should then be negligible.
The principle of positive identification is all the more important because the possibilities of confusion are often so great (the colour of the cap may vary, fragments of veil may be washed away by rain, the volva may be eaten by slugs) that it would be wrong to rely on any summary guidance, or old wives' tales (like the silver spoon test), or negative impression (‘it doesn't really look like a death cap’) for distinguishing the edible from the dangerous species. It is appropriate here to mention some further advice given by Fernald and Kinsey (1943): one should never gather wild mushrooms in the ‘button’ or unexpanded stage of growth; nor gather any which are beginning to decay.
This accounts for most mushrooms eaten, especially in western countries. However, many of the most desirable types of mushroom are not grown commercially, because it has so far been impossible to reproduce in a nursery the specialized conditions which they require. Many cannot feed simply on rotting vegetation but have a complex parasitic or symbiotic relationship with living trees. All one can do is plant trees of the right species, scatter some spores of the mushroom or other fungus, and hope. This is done with truffles, but with only limited success.
However, some mushrooms have been successfully cultivated for a long time. In classical times both Greeks and Romans grew the small Agrocybe aegerita (see pholiota) on slices of poplar trunk. The Chinese and Japanese may have been growing the shiitake on rotting logs for even longer.
Modern European cultivation goes back to 1600, when the French agriculturist Olivier de Serres suggested a method in his work Le Théâtre d'agriculture des champs. In 1678 another Frenchman, the botanist Marchant, demonstrated to the Académie des Sciences how mushrooms could be ‘sown’ in a controlled way by transplanting their mycelia (filaments which spread through the soil underneath them like fine roots). John Evelyn (1699), in a cautious assessment of the worth of mushrooms in the ‘sallets’ (salads) about which he was writing, gives an interesting account of the information then available:
But besides what the Harvest-Months produce, they [mushrooms] are likewise raised Artificially; as at Naples in their Wine-Cellars, upon an heap of rank Earth, heaped upon a certain supposed Stone, but in truth, (as the curious and noble Peiresky tells us, he found to be) nothing but a heap of old Fungus's, reduc'd and compacted to a stony hardness, upon which they lay Earth, and sprinkle it with warm Water, in which Mushrooms have been steeped. And in France, by making an hot Bed of Asses-Dung, and when the heat is in Temper, watering it (as above) well impregnated with the Parings and Offals of refuse Fungus's; and such a Bed will last two or three Years, and sometimes our common Melon-Beds afford them, besides other Experiments.
Melon-beds, as Evelyn suggests, had been found to be good for mushroom-growing, and in the mid-17th century melon-growers in the Paris region had started to take advantage of this to cultivate mushrooms: the first champignons de couche. It was this which led later, in the 19th century, to the practice of growing mushrooms in ‘caves’. Many of these were really quarries, in the Paris region again and in the Loire Valley, from which rock had been taken for building purposes. The quarries of the Loire Valley are still in use, but mushroom-growing in Paris has almost ceased. However, because it was around Paris that the cultivation of Agaricus bisporus began on a large scale, this species, the ordinary cultivated mushroom, is often called champignon de Paris. The mushrooms which bear that city's name are now cultivated all over the world, for example in Taiwan, but France remains a principal grower and exporter. The advantage of a cave is that it provides a stable environment, sheltered from sudden climatic changes. The same effect can be achieved artificially in the mushroom ‘houses’ which are now widely used.
Numerous other mushrooms are now cultivated, including: the oyster mushroom (production of which has grown rapidly); enokitake; shiitake; the straw mushroom; wood ear; and, tentatively, truffles. However, production of the common cultivated mushroom is still dominant. In the mid-1970s the total weight of commercially cultivated mushrooms, worldwide, was approaching a million tonnes annually, and of this nearly 700,000 tonnes were the common cultivated mushroom.
The flavour of the common cultivated mushroom, if it can be detected at all, falls short of that of its wild relations. The same may be true of other cultivated mushrooms; but complaints about them are less often heard.
Alan Davidson was a distinguished author and publisher, and one of the world's best-known writers on fish and fish cookery. In 1975 he retired early from the diplomatic service—after serving in, among other places, Washington, Egypt, Tunisia, and Laos, where he was British Ambassador—to pursue a fruitful second career as a food historian and food writer extraordinaire. Among his popular books are Seafood of South-East Asia, North Atlantic Seafood, and Mediterranean Seafood. In 2003, shortly before his death, he was awarded the Erasmus Prize for his contribution to European culture.
Camporesi, Piero (1998), The Magic Harvest, Cambridge: Polity Press.
Evelyn, John (1699), Acetaria: A Discourse of Sallets, facsimile edn, London: Prospect Books (1982).
Fernald, M. L., and Kinsey, A. C. (1943), Edible Wild Plants of Eastern North America, Cornwall-on-Hudson, NY: Idlewild Press.
