Truffle is one of a type of subterranean mushroom (Tuber) whose fruiting body can be found at depth of 10 to 20 centimetres. It is therefore a painstaking job to find them in their natural habitat. Specially trained dogs have to be used to sniff them out and the pickers then unearth them carefully. The Istrian white truffle (Tuber magnatum Pico) belongs to the most precious and highest quality truffles in the world. The gourmands agree that truffle is the pinnacle of gastronomy, but have not yet agreed whether it is a food or a spice.