Truffle

 

Truffle

A truffle is the fruiting body of a subterranean ascomycete fungus, predominantly one of the many species of the genus Tuber. 

To cultivate truffles, inoculated truffle trees are planted in orchards much like those for fruits and nuts, except that the crop appears below ground and is usually harvested with the help of trained dogs or pigs that can smell the truffles. Orchards should be organic and free of fertilizers, so the best truffle can be produced.

Truffles begin to appear several years (4-5 years) after the inoculated seedlings are planted and production can continue for decades. The onset and duration of production depends to some extent on the species of host tree. Yields vary dramatically: some farms produce as much as 150 pounds per acre each year while others produce little.

Because it is not possible to weed-out competing fungus species, the strategy behind truffle cultivation is to provide the truffle fungus with the conditions it needs to prevail in the competition against other fungi. This competitive advantage is given to the truffles in several ways:

1.      through careful site selection

2.      planting inoculated seedlings

3.      creating soil conditions better suited to truffles than other fungi.

Seedlings inoculated while they are still in the nursery give the truffles the advantage of being there first. It is more difficult for other fungi to become established on roots that are already colonized. Sometimes, it is necessary to add lime to raise the soil pH.

 

 

Cultivated varieties include:

·          Black or Perigord truffle (Tuber melanosporum)

·          Winter truffle (Tuber brumale)

·          Summer truffle (Tuber aestivum var. aestivum)

·          Burgundy truffle (Tuber aestivum var. uncinatum)

·          Oregon Black Truffle (Leucangium carthusianum)

·          Oregon White Truffle (Tuber oregonense)

 

SOURCES

Since the times of the Greeks and Romans these fungi have been used in Europe as delicacies, as aphrodisiacs, and as medicines. They are among the most expensive of the world's natural foods, often commanding as much as $250 to $450 per pound.

Truffles are harvested in Europe with the aid of female pigs or truffle dogs, which are able to detect the strong smell of mature truffles underneath the surface of the ground. The female pig becomes excited when she sniffs a chemical that is similar to the male swine sex attractant. The use of pigs is risky, though, because of their natural tendency to eat any remotely edible thing. For this reason, dogs have been trained to dig into the ground wherever they find these odors, and they willingly exchange their truffle for a piece of bread and a pat on the head. Not a bad trade for the truffle hunter! Some truffle merchants dig for their prizes themselves when they see truffle flies hovering around the base of a tree. Once discovered, truffles can be collected in subsequent years at the same site.

The flavor of the truffle is directly related to its aroma. The chemicals necessary for the odor to develop are created only after the spores are mature enough for release, so they must be collected at the proper time or they will have little taste. This is the only sure indication that the mushrooms are ready to be harvested. That is why animals have proven to be the best means of assuring that the fungi collected will be flavorful.

Although commercial truffles are more plentiful in Europe than in America, fewer are found there now than in the past. A harvest of 2,200 tons was reported in l890. Three hundred tons were harvested in l914, but lately only 25 to 150 tons per year have been found. Truffles appear to have predictable life cycles. To ensure future production, appropriate tree seedlings are inoculated with truffle spores, and when the sapling tree is established, it is transplanted to the proper environment, usually a barren, rock-strewn calcific soil. It takes about seven years before the first truffle begins to grow. A bearing tree will produce for about fifteen to thirty years. For the European market to survive it is necessary to regularly replenish the population of truffle-bearing trees. Inoculated trees have been brought to North America, but it is too early to predict how successful these experiments will be.

Truffles are also found in North Africa, in the Middle East, and in North America. On the desert after rainfall, knowledgeable Middle Eastern people collect the "black kame," Terfezia bouderi, and the "brown kame," Terfezia claveryi. They prefer the darker ones. In Texas, Tuber texensis is collected, and in Oregon, the white Tuber gibbosum.

Gaining in popularity and comparing favorably with the Italian truffle, the Oregon truffle is harvested in sufficient quantity to support commercial sales. Although the Oregon truffle industry is in its infancy, it commands as much as $150 per pound for its truffles. James Beard claimed that the mature Oregon white truffle could be substituted for European varieties.

Originally found in California, the Oregon truffle grows in association with Douglas fir trees and is a major food source for many small rodents and other mammals. These underground fungi depend on animals to remove them from below the surface of the earth and to disperse the spores that result in the continuation of their species. Here is an example of complex ecology in which the tree, the fungus, and the animal depend on each other.

Collecting truffles requires training and experience. A small hand rake or cultivator is used to gently uncover the soil near the base of suspected host plants. As a rule, in the Northwest, these hosts are various kinds of conifer trees. Small freshly made holes at the bases of trees, which are not part of animal tunnels, are excellent indicators that animals have been digging for fungi.

To enjoy the wonderfulness of the variously described pleasure of dining on truffles, you must eat fresh, uncooked specimens shortly after they have been harvested. The strength of the truffle flavor decreases rapidly with time, and much of it is lost before some truffles reach the market. However, lovers of these earthly gems advise us that freshly harvested truffles can be purchased in advance from some local specialty stores. Wholesalers cover them with rice on restaurant serving trays in a refrigerated room as soon as they arrive via overnight air freight. The next day they are delivered to the store where your order was placed. When you spend as much money as will be needed for such culinary experiments, try to assure that you get truly fresh truffles.

The Italian white truffle is considered to be superior in smell and taste to the French black truffle. A black summer truffle found in Germany, smelled to one observer like "a freshly opened can of creamed corn." This black variety is not considered as choice as the other two European truffles.

 

Truffles use in Culinary

Because of their high price and their pungent aroma, truffles are used sparingly. Supplies can be found commercially as unadulterated fresh produce or preserved, typically in a light brine.

As the volatile aromas dissipate quicker when heated, truffles are generally served raw and shaved over warm, simple foods where their flavor will be highlighted, such as buttered pasta or eggs. Thin truffle slices may be inserted into meats, under the skins of roasted fowl, in foiegras preparations, in pâtés, or in stuffings . Some specialty cheeses contain truffles, as well. Truffles are also used for producing truffle salt and truffle honey.

Truffle oil

Truffle oil is used as a lower-cost and convenient substitute for truffles, to provide flavouring, or to enhance the flavour and aroma of truffles in cooking. Many "truffle oils", however, do not contain any truffles, while others include pieces of one of the many inexpensive, unprized truffle varietals, which have no culinary value simply for show.

 

Truffle vodka

Because more aromatic molecules in truffles are soluble in alcohol, it can be used to carry a more complex and accurate truffle flavour than oil without the need for synthetic flavourings. However, many commercial producers of "truffled" alcohol use 2,4-dithiapentane regardless, as it has become the dominant flavor most consumers, who have never been exposed to fresh truffles, but only truffle oils, associate with them. Because most Western nations do not have ingredient labeling requirements for spirits, consumers often have no way to know if additional flavorings have been used. Although used as a spirit in its own right and mixed in a range of cocktails, truffle-flavored alcohol is also used by chefs to flavour dishes.