9. May, 2015

Mushrooms: the food of the gods

“If only one could tell true love from false love as easily as one can tell mushrooms from toadstools.” – Katherine Mansfield.

This week, forty years ago, the small town in which I grew up was in a state of shock. Five members of a poor family died a horrible death while their eldest son – a Grade 8 classmate of mine – looked on, traumatised and unable to help. These poor wretches had collected what they thought were tasty White Parasol mushrooms (Macrolepiota zeyheri) for supper, not knowing that the fungi they had picked were in fact Death Caps (Amanita phalloides) – the most toxic mushroom known to mankind. Only my friend’s adolescent stubbornness saved him – like a typical teenager, he refused to eat mushrooms...  

Despite the awful consequences of mistaken identity, mushrooms have been prized by nearly all civilisations over the millennia. The Romans even named one of the edible Amanita species Amanita Caesarea after their Emperor, and it was colloquially known as “Cibus Deorem” – Food of the Gods. The author Martialis stated that he would sooner decline gold and silver than turn down the offer of a plate of well-cooked mushrooms! Interestingly – and prudently – the Caesars of Rome employed official Food Tasters to ensure that they wouldn’t be poisoned. This precaution was not, however, always successful. Pliny the Elder claims that Agrippina, wife of the Emperor Claudius, murdered him by serving him a hearty meal of lethal Amanita mushrooms on the day of his death in CE 54.

Edible mushroom species have been found at a 13 000 year-old archaeological site in Chile, and written references to them appeared in China nearly 1 000 BCE. The peoples of the Bible didn’t seem to share the Romans’ taste for fungi, perhaps because the Near East was hotter and drier than Europe. In the countries east of the “known world” the Japanese, Koreans and Chinese were however tucking lustily into mushrooms long before the Birth of Christ. I have often wondered how many people had died through trial-and-error “research” before humanity finally determined which mushrooms were edible and which not...

Whereas Europeans used them for purely culinary purposes, the Chinese have long valued mushrooms for their medicinal properties as well. Many cultures around the world – but especially in Central America - have  used, or still use, Psilocybin species (commonly referred to as “magic mushrooms”) for spiritual purposes. Magic mushrooms gained world-wide notoriety in the 1960s, when the Hippie counter-culture used them as an organic alternative to hard drugs.

European cuisine has been immeasurably enriched by the abundance of edible mushrooms and truffles in the deciduous and pine forests that covered most of the continent in ancient times. Names like Porcini, Morel, Chanterelle, Agaricus and, believe it or not, “Trumpets of Death” featured prominently in both the haute cuisine of nobility and the humble fare eaten by peasants. Mushrooms are integral parts of the European diet all the way from Santiago de Compostella in the West to the Ural Mountains in the East. They are cooked in myriad ways while in season, and also dried and pickled for use during winter snow and summer heat.

Foraging for mushrooms has become so popular in Europe that a real risk of inadvertent poisoning has arisen.  In some EU countries, trained and government-certified inspectors will separate edible from inedible pickings for a nominal fee. Handbooks listing names, addresses, and phone numbers of such identifiers in each city are available to the public. Pharmacists in Germany display fresh mushrooms labelled with both common and scientific names. In South Africa, foraging is also growing in popularity, and the collection and consumption of wild mushrooms will no doubt necessitate control and education.  

Farmed Mushrooms

The huge and growing demand for mushrooms has put pressure on naturally-growing stocks, and several species are nowadays successfully farmed. The Button Mushroom (Agaricus bisporus) is the undisputed king of cultivated mushrooms. Called Champignon de Paris in France, it is the most widely cultivated mushroom in the world – nearly 40% of annual global production. Like other members of the Agaricus (Field Mushroom) family, it is a gilled fungus which historically occurred wild in the fields of Europe and North America, but now occurs much more widely.

South African mushroom aficionados may be surprised to know that the three best-known “species” on our supermarket shelves are actually one and the same mushroom – the seemingly nondescript Button Mushroom! It has two color states while immature—white and brown—both of which are marketed under various names. When immature and white this mushroom is variously known as Common Mushroom, Button Mushroom, White Mushroom, Cultivated Mushroom or Table Mushroom. When immature and brown itis called variously a Portobello Mushroom (pl. Portobellini), Swiss Brown Mushroom, Roman Brown Mushroom or Chestnut Mushroom. When mature, it is universally known as simply a “Brown Mushroom”.

Another 25% of the annual output is made up by various Pleurotus (Oyster Mushroom) species, and 16% by Volvariella (Chinese or Paddy Mushroom) species. Lentinus Edodis (Shiitake Mushrooms) contribute about 10% of the harvest. Other mushrooms currently cultivated on a smaller scale include  Enoki, Shimeji and Eringii.

The Wild Ones

Despite the money to be made from commercially producing them, only a fraction of the world’s mushroom consumption is currently cultivated and sold. Commercial cultivation is important ecologically, as there have been concerns of depletion of larger fungi such as the Chanterelles in Europe, possibly because the group has grown so popular yet remains a challenge to cultivate. Numerous species are difficult or impossible to cultivate; they can only be harvested in the wild. When in season they can be purchased fresh, and many species are sold dried as well. The following species are commonly harvested from the wild:

  • Agaricus augustus (Prince Field Mushroom) is a European favourite. One of the best mushrooms for stuffing because it is usually large and the cap forms a deep bowl. Its strong, sweet almond flavour adds an exotic quality to whatever ingredients you select to stuff it with, such as sautéed chopped stems cooked with minced garlic, bread crumbs, fresh tomatoes, and soy sauce.
  • Boletus edulis (Edible Boletus) a native of Europe is known in Italian as Porcino (Pig mushroom), in German as Steinpilz (Stone mushroom), in French as cèpe and in the UK as the “Penny Bun”. It s renowned for its delicious flavour, and much sought after worldwide. Large caps may be prepared as small pizzas. Serve stuffed porcini alongside meat or fish dishes; they are receptive to a wide variety of stuffings
  • Cantharellus cibarius (Chanterelle) is one of the tastiest and most easily recognizable mushrooms, and can be found in Asia, Europe, North America and Australia. There are some poisonous mushrooms which resemble it, though these can be identified fairly easily. Chanterelles have loads of flavour and taste, but are stringy and not easily digestible. It is therefore mostly used in soups, sauces and quiches.
  • Lepista species(Blewits) has a lovely sheen, ranging from golden (Field Blewit) to violet (Wood Blewit) and are very popular in the UK and Ireland. They have also started to appear in the wild in North America and Southern Africa. They are delicate, and should be cooked as little as possible.
  • Craterellus cornucopioides (Black Trumpets or Trumpets of Death) are related to the Chanterelle, but should not be confused with the Black Chanterelle which produces visible veins. They are true wild mushrooms, as they have resisted all attempts to be domestically cultivated.
  • Lactarius deliciosus (Saffron Milk Cap), also known as the Red Pine Mushroom, is one of the best known members of the large milk-cap family. Indigenous to Europe, it has been accidentally introduced to other countries – including South Africa - due to the exportation of conifers. It is consumed around the world, and especially prized in Russia, Catalonia, the Balearic Islands and Gascony. 
  • Morchella species (Morel family) belong to the ascomycete group of fungi. They are usually found in open scrub, woodland or open ground in late spring. Morels must be cooked before eating them. They were designed by nature for stuffing. Fill their hollow interiors with mixtures of ground beef, bacon, lamb, crab, or simply browned onions, bread crumbs, and parsley. Any stuffing will benefit from the morel's fabulous aftertaste. 
  • Tricholoma matsutake (Matsutake or Pine Mushroom) is a mushroom highly prized in Japanese cuisine, and one of the most expensive foodstuffs on earth at US$2,000.00 per kilo. It is indigenous to Northern Asia and America, and is prized by the Japanese and Chinese for its distinct spicy-aromatic flavour. They grow under trees like the Red Pine and certain cedars, and are usually concealed under duff on the forest floor. Though simple to harvest, Matsutake are hard to find, causing the price to be very high. The annual harvest of Matsutake in Japan is now less than 1,000 tons, and this is augmented by imports from China, Canada, the Pacific North-West of the USA and Scandinavia. 
  • Coprinus comatus (Shaggy Ink Cap) must be cooked as soon as possible after harvesting or the caps will first turn dark and unappetizing, then decompose and turn to ink. They are not found in wild-mushroom markets for this reason.

Some wild species are toxic, or at least indigestible, when raw. As a rule all wild mushroom species should be cooked thoroughly before eating. Many species can be dried and re-hydrated by pouring boiling water over the dried mushrooms and letting them steep for approximately 30 minutes.

South Africa’s edible mushrooms

For a relatively dry country, South Africa has a surprisingly large number of endemic mushrooms. As can be expected, most occur in the South Western Cape, with its Mediterranean climate. Some of the edible stalwarts are:

Exotics

  • Boletus edulis (Edible Boletus or Porcino). This very tasty mushroom reached us as a consequence of the establishment of Pinus radiata pine plantations. It is one of the few exotic species to have become widespread in the summer rainfall regions of the country. It is harvested commercially, with most specimens being dried.
  • Boletus badius (Bay Boletus) only occurs in the deciduous and mixed forests of the South-Western Cape.  
  • Leccinum duriusculum (Poplar Boletus) – as the name indicates - thrives in the vicinity of poplar copses. It is found in both winter and summer rainfall areas, and is firm and extremely tasty. It is white initially, turning a grey-brown colour when mature. A large mushroom, it often attains a height of 20 cm+.
  • Lepista nuda (Wood Blewits) are delicate mushrooms with a violet sheen. Another “illegal immigrant” which piggybacked pine trees.
  • Lactarius deliciosus (Saffron Milk Cap), known as the Pine Ring Mushroom in South Africa, was also introduced along with pine trees. It makes excellent eating, and is prized by Cape foragers.

Indigenous species

  • Amanita rubescens (Blusher) only occurs in the South-Western Cape, and is toxic when raw, but delectable when cooked. Pick and eat at your peril...
  • Russula capensis (Cape Russula) is a tasty inhabitant of Cape forests, which has taken a liking to pine plantations. It is the only palatable species in the Russula genus.
  • Coprinus species (Ink Caps) have a distinctive, droopy appearance and need to be eaten as fresh as possible as the “ink” they contain is actually a self-decomposing agent which spoils it within hours of being picked.
  • Agaricus species (Field Mushrooms) are also both indigenous and tasty. All of the ten species are edible, but some are less palatable than others and the yellow-spotted variety (Agaricus Xanthodermis) has been known to cause stomach cramps and nausea.
  • Macrolepiota zeyheri (White Parasol). Another mushroom at home in either winter or summer rainfall regions, this is an indigenous species. It has wonderfully delicate flavour and taste, and appears in clumps in pastures or under Eucalyptus tree. Sadly, its resemblance to the deadly Amanita Death Caps and a shared habitat can lead to confusion and the kind of tragedy I described in the introduction.
  • Termitomyces umkowaanii (Beefsteak Mushroom) is the Goliath among our indigenous mushrooms. Known in the Lowveld and Zululand as “iKhowe”, these mushrooms appear on termite mounds after good rains. They form an important part of the diet of many indigenous people, because they become available before the cultivated summer crops. These giants can reach a height of more than 50 cm, and can weigh more than a kilo. Zulu herdboys love their iKhowe for breakfast, and will unceremoniously fry pieces on a stick over an open fire. The good news is that these mushrooms – notwithstanding their size – are delicate and packed with  beefy, Porcini-like flavour. You can use any of your favourite mushroom recipes on them. Simply pan-fried with garlic and butter is my idea of the real deal, but iKhowe can be the basis of a really fine Alfredo sauce for pasta too.

Poisonous mushrooms to be avoided

  • Amanita phalloides (Death Caps) contain a deadly toxin that attacks the human liver and kidneys, and causes agonising death within hours.It can easily be confused with the delicious White Parasol mushroom (Macrolepiota zeyheri) – the only distinguishing features of the Death Cap are a yellow sheen on the cap (not always visible) and a volva (shield) around the base of the stem, which is absent in the case of White Parasols. Don’t touch them, and if unsure wash your hands thoroughly with hot water and detergent after contact with suspect mushrooms.
  • Amanita pantherina (Panther Cap) is easily recognisable because of its light brown cap, speckled with white warts and the presence of a volva at the base of the stem. It is the most common of our Amanita species, and occurs throughout the country – it is equally attracted to pine, eucalyptus or deciduous forests and copses. It is potentially deadly.
  • Lepista caffrorum (Deceptor) is common in Gauteng towards the end of good rainy seasons. It can easily be mistaken for a squat Field Mushroom or even a large feral Button Mushroom. While it is not deadly, it can cause severe abdominal cramps, delirium and permanent damage to the liver and kidneys.
  • Amanita muscaria (Fly Agaria) is dangerous precisely because of it deceptive good looks. It is cap is bright red with white spots – just like the toadstools in children’s books about Bambi or Little Red Riding Hood. Fortunately it resembles no edible mushroom and can be avoided easily. It is not deadly, but causes severe and unpleasant hallucinations. It is widespread throughout South Africa and abundant during the rainy season.
  • Omphalotus olearius (Copper Trumpet) resembles the sought-after Saffron Milk Cap or Pine Ring but fortunately does not share the same habitat. The Milk Cap has a symbiotic relationship with pine trees, whereas the Copper Trumpet is found under Oleander, Oak and other broad-leaf trees. The latter has another interesting feature: it is bioluminescent. A biochemical substance called luciferin makes it glow dimly but visibly in the dark! It causes abdominal pain and a runny tummy, but is not deadly.
  • Chlorophyllum molybditus (False Parasol) is the stuff of legends. After good summer rain It often appears in “Fairy Rings”, with dozens seemingly planted in circular formation. It is almost a dead ringer for the edible White Parasol, except that the latter has pinkish-white gills under the cap whereas the gills of the poisonous False Parasol are greenish. Another distinguishing feature is that the False Parasol only occurs in summer rainfall areas, whereas its edible lookalike prefers the Mediterranean climate of the Cape. Fortunately the False Parasol is not deadly; it does however cause stomach cramps and nausea.

Cooking and eating mushrooms

Eating mushrooms is one of life’s real pleasures, as long as one goes about it the right way. Some of the things I would urge readers to bear in mind are:

  • Never eat what you don’t know. Even though there are many excellent field guides available, I urge readers to not embark on a DIY course in mushroom identification. Rather join a club or engage the services of a qualified guide like Gary (“Mushroom Guru”) Goldman to get you started safely.
  • Eating Raw Mushrooms: With a few exceptions, such as store-bought mushrooms, I would not recommend that any wild mushrooms be eaten raw. Uncooked mushroom tissues are poorly broken down for digestion, depriving us of their nutritional contents. Many varieties of wild mushrooms are disagreeable when eaten raw because of viscid surfaces or peppery characteristics. However, they become readily digestible and delectable when cooked.
  • Waste not, want not. If you have more mushrooms than you are likely to use in your next meal, do not just leave them to their own devices. Mushrooms spoil very quickly, particularly the softer kinds like Blewits and Ink Caps. They last much longer if they are cooked, so rather sauté the surplus briefly and refrigerate or freeze them.
  • Duxelles. Another excellent way of utilising surplus mushrooms and/or offcuts is to make duxelles. This is a finely chopped mixture of mushrooms, onions or shallots and herbs sautéed in butter and reduced to a soft paste. It is a basic preparation used in many stuffings and sauces or as a garnish. Duxelles is made with any cultivated or wild mushroom, depending on the recipe. A duxelles made with robust wild mushrooms like Porcini or Chanterelles will obviously produce much stronger flavor than one made with white or brown mushrooms. 
  • Slicing Mushrooms: Slicing mushrooms allows for more rapid cooking and water loss than when mushrooms are cooked whole. Cut them into uniform thicknesses and they will cook more evenly. Mushrooms with mild and subtle flavours should be cut into large pieces so that their savoury juices can be better appreciated. The best tool for cutting mushrooms is a short (no more than 15 cm), sharp utility knife. Because the caps have varying sizes, shapes, and textures, cut mushrooms in half so that they will lie flat on the surface of the cutting board. Soft species such as shaggy manes are difficult to cut unless the knife is sharp and the cut firm. 
  • Using Butter and Cream: Butter seems to enhance the flavour of most mushrooms, except for some of the Asian varieties such as Matsutake. It is best to use unsalted butter in cooking. Lemon juice helps mushrooms maintain their colour and adds zest to their flavour. Mushrooms in some recipes seem to taste much better when cream is added. It is a culinary reality which flies in the face of the current trend away from creamy sauces. Use milk instead of cream if your diet is of greater importance than taste... 
  • Adding Salt: Sadly, many mushroom lovers have to limit their salt intake for health reasons. It is therefore better to use salt sparingly during cooking, and let guests add the amount they feel comfortable when the mushrooms are served. Salt should be added towards the end of cooking, since it tends to remove water from mushroom tissues and makes them too soft. 
  • Intensifying Flavour: Mushrooms exude liquid when sautéed in oil or butter. Many chefs prefer to cook most of the fluid off to develop the maximum intensity of the mushroom's flavour. Some recipes require browning the mushrooms to create more flavour. While doing this, constant vigilance is required to avoid burning. 
  • Drying mushrooms. Those of you fortunate enough to indulge in the age-old pastime of foraging for wild mushrooms might also enjoy preserving some of your bounty for future use. Their taste will usually be altered in the process. Sometimes the flavour becomes more intense, and sometimes certain varieties of mushrooms take on nuances not found when fresh. Begin by selecting firm mushrooms that are in good condition. When cleaning, try to prevent the mushroom from taking on water, which is what we want to get rid of. Do not rinse mushrooms – wipe them with a brush or a slightly damp cloth. Trim the stems and cut them into flat, even slices about 1 ½ cm thick, so that they will dry at the same speed. Leave on a mesh surface in a warm, well ventilated place. When the slices are bone dry, place them in metal or glass jars. Be sure to label containers with the date and the species identification. 
  • Using dried mushrooms: In using dried mushrooms, first rinse them quickly under the faucet and then place them in a bowl. Pour enough lukewarm water over them to cover and soak for the recommended period of time, normally at least 15 to 20 minutes. Remove the mushrooms and squeeze them dry. Save the soaking liquid for use in your recipe since much mushroom flavour will have been released while rehydrating. Decant the soaking liquid slowly to avoid adding sediment that has settled to the bottom of the vessel. 
  • Freezing mushrooms is quicker and easier than drying, and just as fine a technique for preserving mushrooms. They can be frozen fresh or precooked. Smaller specimens may be frozen whole, after examining, cleaning, and completely draining them. Allow 20 to 30 minutes for draining. Larger specimens should be sliced or cubed into 5 mm pieces. “Ziploc” freezer bags work well as do airtight Tupperware-type containers. There are two methods of precooking mushrooms for freezing. One way is simply to freeze a dish made with mushrooms, such as a quiche, ready to heat and serve. The other is to sauté the mushrooms in butter or oil, or both, for 5 minutes before transferring them to a freezer container. Be sure to include the liquid remaining in your saucepan. Properly prepared, the mushrooms will keep for up to 6 months.

I hope the thoughts and suggestions above will prove useful and inspiring to lovers of this noble fungus, and that they may even have converted a few Philistines...

“Friends are like mushrooms – they sometimes spring up in out-of-the-way places.” – Anonymous.