Truffles are the spore-producing parts of an edible fungus in the family Tuberaceae which lives underground, especially around the roots of trees in damp forests. Botanically, they are a species of mushroom and range from about the size of a walnut to the size of a fist. Because they occur naturally around the roots of trees, truffle hunters once used pigs to find and dig up wild truffles. Today, specially trained dogs are used, in large part because pigs typically eat most of the truffles they locate, while dogs can be more specially trained.
Prized for their flavour and aroma, truffles are rare, difficult to source, and once harvested, they quickly lose their potency, all of which combine to make them one of the world’s most expensive foods. Some varieties of truffles can sell for as much as $2,000 per pound.
Increasingly, truffles can be cultivated. The method involves inoculating young trees with spores of the truffle fungus then planting those trees in orchards. Today, up to 80 per cent of French truffles come from truffle orchards like these.
Some cooks use truffle oil, which is made by infusing oil with one of the flavour compounds found in truffles. But truffle oil isn’t made with truffles, even the kind with bits of truffle in the bottle, and the flavour of truffle oil is quite different than the flavour of true fresh truffles. It is, however, a flavourful ingredient that is much more affordable than actual truffles.
The black truffle, also known as the Perigord truffle after the region in south-western France, and the white truffle, which comes from the northern Italian region of Piedmont, are among the most popular. The summer truffle, or Burgundy truffle, is also highly prized. Other edible truffles include the pine truffle, the whitish truffle, and the garlic truffle.
The flavour compounds in truffles are extremely volatile, which means that when heated they evaporate and quickly disappear. For this reason, it’s rare to actually cook truffles. Instead, it’s typical to shave them thinly over the top of hot, cooked food before serving, letting the warmth of the food activate the flavours and aromas. This is especially true of white truffles.
To highlight the truffle’s unique flavour, it’s usually best to serve them with foods with otherwise simple flavours, like eggs or pasta. They can also be grated into wine- or cream-based sauces. Thin shavings can be placed under the skin of poultry before roasting or shaved onto cooked meats like beef, pork, boar, or venison before serving.
With black truffles, the conventional wisdom is that their flavour can be enhanced by very gentle cooking, such as stirring them into a sauce and heating at the end of cooking. Because their pungent aroma and distinctive flavour can overwhelm if used too heavily, as well as their cost, truffles are used sparingly.