Truffle FAQ - Section II, Basic Truffle Facts

Copyright © 1998, Tanith Tyrr and respective contributors

Truffle (truf'l) 1.) Subterranean, edible ascomycetous fungi of the genus Tuber. Found anywhere from 2 to 15 inches below the ground, usually in a circular formation about 4 to 5 feet from the base of an oak tree. A number of varieties exist. 2.) Black Truffles, of Perigord and Lot are highly esteemed as the absolute finest in the world. "Truffle" oaks are also found in areas of France including Dauphine, Burgundy and Normandy, but these are all inferior in quality, with a less delicate aroma and taste. White Truffles are found in Piedmont, and have a slightly garlic flavor. 3.) Reference to a candy made of soft chocolate, shaped into a ball and dusted with cocoa; or, sometimes a 3 layered cube of light and dark chocolate. (Thought to resemble the shape and color of the fungi, circa 1585-95.)
- Random House Dictonary

Truffle Basics: Fun Facts About Fungi by Robert Fogel
Truffle Hunting: Gold In The Soil by Robert Fogel
Traditional Truffle Hunting: Truffle Dogs (from Ctainformatica)
Electronic Apparatus for Truffle Searching by John@jmsknars.demon.co.uk
Edible North American Truffles by Daniel B. Wheeler
The Italian White Truffle by Elsy@itbiz.com
A Truffle Bibliography

Truffle Basics: Fun Facts About Fungi

Researched and written by Robert Fogel (rfogel@umich.edu) and supported in part by National Science Foundation Grant 9400871. Text edited by Patricia Rogers.

Truffles have fascinated people for thousands of years. Their attraction is a tantalizing taste and aroma which, once experienced, can never be forgotten. The taste and aroma of commercially collected truffles is so intense that they are used as a flavoring instead of a separate dish. Magical powers and virtues have even been attributed to truffles. They have been collected for at least 3600 years. Growing underground, they are difficult to find and very expensive as a result. Every Spring, truffle hunters in Europe take to the woods, hoping that the sensitive noses of their trained pigs and dogs will lead them to buried treasure. In 1994, black truffles sold for $350 to $500 a pound.

The name "truffle" has been borrowed to describe small, fancy chocolate candies, another expensive and delicious food. Real truffles are roundish, brown, and dirty when they come out of the ground. They are the fruit of the truffle organism, like apples are the fruit of an apple tree. Truffles contain spores for reproduction the way an apple contains apple seeds.

Many animals can easily reach fallen apples, and so spread their seeds by way of uneaten cores, or in dung. Since truffles are buried in the soil, truffles rely on partnerships (symbiosis) with certain animals for spore dispersal. Squirrels and chipmunks dig up truffles in the same way they may steal flower bulbs in your garden. They are the major wild animals dispersing truffle spores in North America.

Truffle-producing fungi have also formed symbioses with trees (mycorrhizae) because fungi cannot make their own food. The hyphae, or thread-like non-fruiting part of these fungi, coat the roots of the tree and help their host absorb soil minerals. In return, the tree host provides the fungus with carbohydrates and other nutrients, the product of the tree's photosynthesis.

Attempts are being made to farm truffles due to the difficulty in finding them in the wild. The harvest has steadily decreased for the last 90 years, due to forest destruction and the killing of trees by air pollution. France produced 1,000 metric tonnes of truffles in 1892; now, only 50-90 tonnes are harvested each year.

Truffle Hunting: Gold In The Soil

by Robert Fogel

Truffles are difficult to find and very expensive as a result! In 1994, black truffles sold for $350 to $500 a pound. In the United States, edible truffles are collected in the forests of Oregon and Washington. In Europe, most truffles are collected in France and Italy.

Truffle hunters in Italy and France use pigs and mixed-breed dogs to sniff out truffles. Dogs are preferred to pigs because pigs love to eat truffles. Notice the staff held by the truffle hunter in the picture with the pig. The hunter uses the staff to force the pig to back off, once the pig has located a truffle.

In Italy, truffle dogs are trained in several steps. First, the dog is taught to retrieve a rubber ball. Next, a small bit of smelly Gorgonzola cheese is substituted for the rubber ball. After the dog has learned to retrieve the cheese, the cheese is hidden, forcing the dog to sniff it out for a reward of food. Finally, a small truffle is substituted for the cheese. The dog is trained to fetch, then dig up the truffle.

Dogs like other food better than truffles, so bread and other treats are used for rewards. The night before a truffle hunt the dog is not fed so it will be eager to find truffles for the treat. Some dogs take the easy way out. They find and eat garbage buried by campers! Dogs generally do not find young truffles because the odor is too weak. The odor becomes stronger with age as the spores mature.

The value of commercial truffles means that there are laws controlling their collection. In Italy, for example, truffle collectors are tested and licensed. There, organizations of land owners called cooperatives control truffle hunting on their property. Unless you are a member of the cooperative, you can be arrested for collecting truffles from cooperative truffle beds.

In North America, truffle collectors use three major clues to find truffles. First, it must be warm and the soil moist. Truffles are often found 10 to 14 days after a heavy rain. The umbrella shaped mushrooms which pop up after a good rain can be used as a kind of clock. Look for truffles after these mushrooms have started to collapse.

Second, the right trees present must be present. Truffles are formed by fungi that are partners (ectomycorrhizal) with certain trees. You will not find truffles under maples, for instance, because maples do not form ectomycorrhizae. Trees to use as clues include: pines, firs, Douglas-fir, oaks, hazel nuts, hickories, birches, beeches, and eucalyptus.

Third, truffles use animals for spore dispersal. In North America, squirrels and chipmunks are the major wild animals dispersing truffle spores. Search among the right trees for pits dug by rodents in their own hunt for truffles. Pits do not guarantee success, however! Rodents also dig pits searching for acorns, onion bulbs, and beetle grubs.

The best success results from raking around fresh pits. Look for pits not filled with leaves or other debris. I use a four-tine garden cultivator with the handle shortened to 30 inches to rake leaves off the surface and dig into the soil 3 or 4 inches (8 to 10 cm). A good eye is required as many truffles are small and colored red, brown, white, or even black.

Bring a supply of small paper bags for taking your truffles home. Write your collection notes on the bag before putting the truffles inside it. Information on fresh appearance and habitat is often needed to identify fungi. Note the color and shape of the truffle, and what kind of trees are close by. The date and precise location are also useful information. These data can help you understand when and where to look next year.

Do not put truffles in sealed plastic bags. If you do they will mold, get slimy, and smell bad! NEVER EAT ANY TRUFFLE, OR OTHER FUNGUS, UNLESS IT HAS BEEN IDENTIFIED BY AN EXPERT! You might confuse the button stage of a poisonous mushroom with a truffle, or be allergic.

Hunting truffles is like hunting buried treasure. Good luck!

World Wide Web References by Dr. Fogel:

Robert D. Fogel, Fungal Ecology & Systematics.
http://www.biology.lsa.umich.edu/faculty/fogel.html

Robert Fogel, Curator of Fungi. Research Interests.
http://141.211.110.91/Fogelcv.htm

Fogel Storage. Useful scientific information on the identifying characteristics and categorizations of various fungi.
http://141.211.110.91/fam_map/fogel.htm

Fun Facts About Fungi by Robert Fogel
http://141.211.110.91/kidpage/truffact.htm

Traditional Truffle Hunting: Truffle Dogs

Adapted from CTAINFORMATICA

"The Romagna Water dog is specialized in searching for truffles. It is an ancient water retriever breed which has been kept since the 16th century in the Comacchio valleys and the Ravenna lagoon, and spread after the 19th century to the plains and hills of Romagna. This breed is a typical water dog, medium-small size, mesomorphic, squarely built, its general appearance is rustic, strong and well-proportioned. Its hunting instinct has been canceled out, so it is not distracted by game. Affectionate and very attached to its master, it is also an excellent companion dog, very trainable."

Electronic Apparatus for Truffle Searching

Source: The Knaresborough Post, Friday, March 2, 1990
by John@jmsknars.demon.co.uk - this material copyright JMS 1996

A Knaresborough gas detector has been trying his hand at truffle tracking in the South of France.

Mr John Sonley of Lands Lane has been giving expert advice on how to find the increasingly rare truffles, which are used to make the regional delicacy Pate de Fois au Truffle.

The large black muchrooms are becoming scarce, with the dogs and pig trackers, currently used to sniff them out, failing to find enough to cope with the demand.

Mr Thierry Talou, who is studying vapours associated with truffles as part of his PhD at Toulouse University asked Mr Sonley to look at ways of helping to solve the problem.

Now Mr Talou is appealing to the French government for funds to help Mr Sonley continue his research.

"He asked me to find an electric nose, not to replace the dogs and pigs, but because they tire very quickly and then they are no use for the rest of the day. So when the animals have had enough, the machine will continue. Having seen the dogs in operation I don't think anything could replace them", said Mr Sonley.

Truffles are usually found between two and four inches under the ground,at the root of Oak trees.

Black Perigord Truffles (Tuber Melanosporum) are underground mushrooms which grow in symbiosis with certain trees, especially oaks. During a limited harvesting season, they are found in several regions of southern Europe, France, Italy and Spain. The Black Truffle is highly valued by gourmets for its typical flavour, to the extent of being called 'The Black Diamond of French Cuisine'. For the past five years the production of truffles was reported between 30 - 100 tons for Europe with a price of 300-500 per kg (the potential demand of consumers could be estimated at 150-200 tons).

Their harvesting is a delicate and always uncertain operation. Indeed, because truffles remain underground even after maturing, the acute sense of smell of certain animals is required to find them. Traditionally pigs were used but they are being replaced by dogs. The fine sense of smell of the pig makes it very efficient, but it requires constant firmness and vigilance, because there is a high risk of truffles being unearthed with the snout and being damaged, or even swallowed. Moreover the animal tires rather quickly and its transport is difficult. Unlike pigs, dogs are not naturally interested in truffles and can be trained to indicate with their paw the place where they scent a truffle. Although no race of dog instinctively looks for truffles, hunting dogs are not used as they are more inclined to sense game than truffles.

At present there are little statistical data on the number of animals searching for truffles, especially for pigs which are generally killed at the end of the season (March). For dogs, 1000 are suggested for the whole of Europe, of which 500-600 are very efficient. The cost of a trained dog, including the sale price and maintenance for five years is estimated at �1000-�2000.

There is a potential market for electronic apparatus; a good detector/sampling system would be welcomed if its price did not exceed �2000. During the first years of exploitation 25-50 sets of apparatus would be required for demonstration tests among both truffle producers (personal use and truffle contests) and trufflemanufacturers. For the next year there is a market for approximately 300-500 units in Europe (perhaps 500-1000 with extensive marketing).

As an estimate, the potential market for Europe could be 500 units for the first two years marketing - (France: 200; Spain: 70; Italy: 130) and a turnover of about �1,000,000. The potential purchasers of this kind of apparatus are mainly truffle producers and farmers.

Thierry Talou,
Ingenieur de Recherche,
Laboratoire Chimie Des Agroressources

Edible North American Truffles

by Daniel B. Wheeler http://www.oregonwhitetruffles.com)

North America has an abundance of underground fungi collectively termed truffles. These truffles can be ascomycete, basidiomycete or zygomycetes. Not all truffles have been tested for edibility. Most have unknown edibility at this time. A substantial number have only recently been found for the first time. Thus identification should be positive before consuming any unknown truffle.

All members of the genus Tuber are considered "true truffles", and are considered safe and edible, to varying degrees. They are not known to cause any illness in people, and generally are eagerly sought after world-wide.

Species include:

Tuber gibbosum Harkn., also called Oregon White truffle. This species is apparently species specific with Douglas fir (Pseudotsuga menzesii), and is most abundant during late summer through early winter. The aroma can be cheesy, or smell of freshly roasted hazelnuts. Some specimens can have a dry-white-wine aftertaste. Most people, according to a study by Anna Marin, enjoy the aroma. In 1984 the late James Beard sampled this truffle at Linn-Benton College in Albany, Oregon. He said it was "at least as good...as (Italian White) truffles." It was first found in California near San Francisco by Dr. Harkness in 1878, and later described by him in 1898.
Tuber californicum is called California Black truffle. It is a small, nearly perfectly spherical truffle with strong association with California hazel. While it has been reported nearly year round, it is more commonly found in winter and spring in Oregon. While truffles are small, it is prolific. Finding "nests" of 50-60 sporocarps have been documented. This species often needs a little sweetener added to it. Try it grated into butter and honey on fresh baked French bread, or in dark gravies.
Tuber giganteum Gilkey, first described as a separate species by Dr. Helen Gilkey from collections uncovered near Corvallis, Oregon under Douglas fir. Dr. Gilkey later revised the name to Tuber gibbosum Harkn. because she could see not gross differences from that fungus. Later, Dr. James Trappe re-used the name to describe a dark greenish-to-blackish gleba truffle, frequently found in a single Christmas tree plantation near Oregon City, Oregon. This fungus can have a nearly black interior when mature. While it has been reported as early as December, the normal fruiting period is from January through June (rarely July). The aroma is strongly of Tuber gibbosum, even when immature, becoming stronger. At maturity, the aroma is similar to dried black morels. It has stronger, smokier flavors and holds up to cooking better than Oregon White truffle. At least one Portland chef uses it slivered in mashed potatoes with a light white sauce dressing.
Tuber murinum, or Pallid truffle, is generally a summer-fruiting species found with Douglas fir. This species has pale, nearly colorless spores. The aroma is similar to Tuber gibbosum, so it is often sold as Oregon White truffle. The internal veins are usually more common and more close together. Specimens up to 8 cm across have been collected, some as deep as 10 inches. It favors very loose soil, and is not uncommon in Christmas tree plantations.
Tuber spinoreticulatum is found with some Douglas fir in Oregon. It is easily distiquished from other truffles by a complex, deeply divided bodies. Additionally, the peridium can be either warted or wrinkled. I could not distinquish the odor from a Tillamook Sharp Cheddar, and encourage using cheese and eggs with this truffle in either fondues, omlettes, quiche, pasta salads, or casseroles.
Tuber sp. nov. (new species) is found with Grand fir in July in Oregon. It has been found rather deep in clay soil. It is generally less than one inch in diamter, and is seldom searched for.
Another Tuber sp. nov. (new species) is found with Douglas fir in Oregon in early spring to early summer. This species is distinguished by having small chambers leading into the gleba from the external veins of the truffle. Additionally, the external veins are over 1 mm wide, and are less abundant than in most truffles. It sometimes reaches 5 cm in diameter, and has been included with Tuber giganteum in taste and texture.
Leucangium carthusiana, or Oregon Black truffle, is found with Douglas fir from November through April in most years. It has black pyramidal warts on the outside, and a largely black interior (gleba) with white, yellow or orange interior veins. The aroma is highly sought, and is fruiting, with tinges of pineapple, papaya, coconut and Bailey's Irish Cream. It makes a valuable addition to meats, especially fowl; and is included with most other traditional truffle recipes.
In addition to Tuber species, the Pacific Northwest is also home to many hypogeous basidiomycetes which have considerable culinary interest. Some of these are:
Alpova diplophloeus, or Red Alder truffle. This edible species has many fatty-acids, and has a rich fruit/meat/wine aroma. Flying squirrels often search it out in early fall. While it can reach over 5 cm across, usually it is smaller than 3 cm. Collections have been found nearly year-round, but it is far more common in early fall. Look for it after the Red Alder leaves have fallen off the trees.
Martellia gilkeyae, is species specific (found only with) Western hazelnut. I have found it in Oregon in March through May. It has an aroma similar to grapefruit LifeSavers, and sliced into omelettes, reminds me of a Springtime chanterelle.
Martellia brunnescens, or the Browning Martellia, is a common hypogeous fungus found with young Douglas fir and Western hazelnut. It is featured in many dishes, from soups to salads to cheese and egg dishes. It is also valuable as inoculant for seedling trees.
Rhizopogon rubescens is often found with long-needled pine trees on both the west and east coasts of the United States. Some specimens can be spectacularly large. One specimen weighing nearly two pounds was featured on the cover of the December, 1996-January 1997 NATS Current News, and was found by Catherine Miller on October 14, 1996 in the Umpqua National Forest of Oregon. It is also reported to be common in the Southern U.S. with Loblolly and other pines. While it is more often kicked than quiched in the U.S., Japanese esteem it, especially sliced thinly in soup with buckwheat noodles.

Daniel Wheeler's North American Truffles database is available on his excellent website.

Here is a photo of some North American truffles.

The Italian White Truffle

Site maintained by elsy@itbiz.com
From http://www.langhe.com/langa/roe040.htm

The white truffle, scientifically known as tuber magnatum Pico, is an underground fungus belonging to the ascomycetes family. The truffle grows in symbiosis with certain trees, in particular oaks, willows, limes and poplars. Its delicacy, intensity of aroma and colour, which can be as dark as milk coffee with pale streaks, may vary depending on the plant it grows under. Every truffle-hunter knows spots where the precious fungus can develop, and the secrecy surrounding the search - which begins by law on 15 September and ends on 31 January, although the 'tuber magnatum Pico' reaches its peak in terms of quality towards the end of autumn - is legendary.

See a photo of some Italian white truffles courtesy of Renato Bertello, the webmaster of Itbiz.com. Italian Business Trade On Line is an excellent source for chefs seeking to directly import produce from Italy.

Truffle Bibliography

Bibliography recommendations from: Gene Heller <evergene@sirius.com>, Tanith Tyrr, Daniel Wheeler http://www.oregonwhitetruffles.com) and Robert Fogel (rfogel@umich.edu)

Culinary and historical references:

"The History of Food", by Maguelonne Toussaint-Samat (Blackwell Publishers, 1994) contains a section called The History of Truffles (pages 434-441). It surveys several thousands of years of writing about truffles. It also includes a fair amount of information about current truffle production in France, Spain and Italy.

"Serve It Forth", by M.F.K. Fisher (North Point Press, 1989), has a wonderful account of "the last virgin woman truffle-hunter in all of France!" ("...we had to gather secretly because the Church was opposed to women truffle-hunters. The idea of an old virgin sniffing over the hills, with a pack of men hot at her heels -- it is disgusting to the Church...") Both of these sources also discuss the aphrodisiac qualities of truffles.

Food In History, by Reay Tannahill, Crown Publishers 1989 ISDN 0-517-88404-6 Brief but valuable references to the earliest known culinary uses of truffles. "Truffles had been known in Babylon as well as in Rome...in France truffles remained sunk in obscurity until the fourteenth century... That they were eaten at all was probably due to their reputatin as an aphrodisiac. ...Then truffles became so fashionable that the demand trebled, and so did the price."

Savoring The Past: The French Kitchen and Table from 1300 to 1789 by Barbara Ketcham Wheaton, Scribner, 1983 ISDN 0-684-81566-4 Many period recipes described which include truffles; a good overview of the general culinary philosophies of the period.

Apicus: Cookery and Dining in Ancient Rome, edited and translated by Joseph Dommers Vehling, Dover edition 1977, ISDN 0-486-23563-7 Some good references to the use, preservation and storage of truffles in ancient Rome.

The Compleat Housewife (1758) by Eliza Smith, Studio Editions Ltd 1994, ISBN 1-85891-121-4 Brief reference to a dish of "Lamb's stones [testicles] and Morels & Truffles Ragoo". Mainly plain English cookery, few other references to truffles, a good overview of the humbler cooking of the period. Poorly indexed, unfortunately.

Larousse Gastronomique by Prosper Montagne, introduction by Auguste Escoffier, English edition 1961, Crown Publishers Inc, New York. An enduring classic of French cuisine originally published in the last century; no serious chef should be without one. A large section on truffles as well as many recipes featuring truffles.

The Physiology of Taste by Jean Brillat-Savarin, reprinted 1948 by Liveright Publishing Corporation (and more recently by other sources) The singular classic of gastronomy that defines and shapes refined French cuisine in the 1800's to the modern day. Much use and description of many kinds of truffles and their culinary applications.

Scientific references and field guides:

Smith, H.V. and A.H. Smith. 1973. How to know the non-gilled fleshy fungi. W. C. Brown, Dubuque, IA

Aurora, David. 1986. Mushrooms Demystified, 2nd edition. Ten Speed Press, Berkeley, CA 94707. This is the single most useful book available on the market today of fungi. It has a relatively large section on various hypogeous fungi, including truffles. Highly recommended for any mushroom hunter or mycologist.

Chang, Shu-ting, and Hayes, W.A. 1978. The Biology and Cultivation of Edible Mushrooms. Academic Press, Inc., Orlando, Florida

Hall, Ian. 1994. The Black Truffle: Its History, Uses and Cultivation, 2nd edition. New Zealand Institute for crop & Food Research Limited, Christchurch, New Zealand. A wonderful, small coffee-table book with terrific recipes, truffle physiology, mycorrhizal association, fruiting parameters, and sources.

Back to the Truffle Basics FAQ.
Back to the Truffle Culinary FAQ
Learn more about Truffles in History

See a photo of some Oregon white truffles courtesy of Daniel Wheeler.