Different species of underground fungi commonly called truffles belong to the genus Tuber, the Tuberaceae family, the class of Ascomycetes. Truffles have an underground fruiting body and grow naturally in the soil next to the roots of certain trees or shrubs, especially oak trees, with which they establish a symbiotic relationship (mycorrhiza).
What is commonly meant by truffles is only the underground fruiting body that is detected with the help of dogs and then hand-picked by the hunters. The truffle is a highly prized and sought after, very expensive food. The typical penetrating and persistent aroma develops only after curing and is designed to attract wild animals (pig, wild boar, badger, dormouse, fox), in spite of the ground cover, to spread the spores contained and perpetuate the species.
Terfezie, of terfeziaceae family, are also commonly included under the truffle denomination and they are also known as desert truffles. They are endemic of desert and semi-desert areas of the countries surrounding the Mediterranean, where they are much appreciated.
The science that studies truffles is called idnology, a term that comes from the Hydnon, the greek word for truffle.
These are the varieties of truffles which can be picked in Italy. There are other species, which are slightly toxic and have a nauseating odour and therefore do not lend themselves to the picking. There are no toxic or poisonous species.
Fine white truffle, Tuber magnatum Pico from 21st September to 31st January.
Fine black truffle, Tuber melanosporum Vittad. from 1st Decemeber to 15th March.
Tartufo moscato, Tuber brumale var. moschatum De Ferry from 15th December to 15th March.
Summer black truffle, Scorzone, Tuber aestivum Vittad.from 1st June to 31st August and from 21st September to 30th November.
Hooked truffle, Tuber uncinatum Chatin from 21st September to 31st December.
Winter black truffle, Tuber brumale Vittad. from 15th December to 15th March.
Bianchetto o Marzolino truffle, Tuber borchii Vittad. = Tuber albidum Pico from 15th January to 30th April.
Smooth black truffle, Tuber macrosporum Vittad. from 21st September to 31st December.
Ordinary black truffle or Bagnoli truffle, Tuber mesentericum Vittad. from 21st September to 31st January.
Truffles are relatively rare, since their growth is dependent on seasonal as well as environmental factors. In certain years of particularly low yields, truffles have reached very high prices (Tuber magnatum, the finest variety of white truffle, has come to EUR 4,500 per kilo).
Italy is one of the world's largest producers and exporters of truffles. All the varieties of truffles used in gastronomy can be picked in the country.
The areas in italy that yield are Piedmont (especially Alba, in the province of Cuneo, the province of Asti and a part of the province of Turin), south-eastern Lombardy (Carbonara Po, near Mantua, in a protected Island Boscone), Emilia-Romagna (along the Apennines from Piacenza onwards, and in particular the hills around Bologna and Forli), Tuscany (especially San Miniato, near Pisa and San Giovanni d'Asso, near Siena), Umbria (Citta di Castello and Gubbio, near Perugia), Marche (Acqualagna and Sant'Angelo in Vado, near Pesaro and Urbino respectively), Abruzzo (especially Ateleta,near L'Aquila) and Molise, where the areas of greatest collection are those around Larino near Campobasso, Spinete near Frosolone, and finally San Pietro Avellana and Vastogirardi near Isernia.
The delta of the Po river in Veneto is another area that is well suited to the production of black truffle and also of Tuber albidum, also known as marzolino or bianchetto.
In Italy it is possible to pick truffles all year round, except for the period at the end of April. Traditionally, truffles are hunted using a pig. The problem with this method is that the pig is fond of truffles, and it must be held to prevent him from eating what it has found.
Nowadays in Italy truffles are hunted exclusively with trained dogs. No particular breed is used for this task, except for the Lagotto Romagnolo, and generally small mixed breed dogs are preferred. In France, particularly in the Lot and Périgord regions, highly trained pigs are still used to this day to hunt truffles; this tradition in Italy was abandoned after World War II as a result of the growing demand for truffles and the creation of "training schools" for truffle hunting dogs.
Despite the association of the image of the wild boar with that of truffles, this animal has never been used for truffle hunting because of the difficulty of controlling such a wild and untamed animal.
The cultivation of the truffle is at an experimental stage in Italy and France. To create a land suitable for intensive production of truffles or truffle cultivation, it is necessary to choose land rich in limestone and with low levels of humus, then it is necessary to plant trees and shrubs that will feed the variety of truffle chosen(oak, hazel, willow, holm oak). The seedlings are previously "mycorrhized", which is to say that the roots are already in symbiosis with the selected fungal hyphae. When tried with the most prized species of truffle (Tuber magnatum), the results have been disappointing, while with other varieties the production achieves excellent levels of quality and quantity. Given the strong demand for the product though, we have yet to see a strong impact on prices.
Excellent results have been obtained with the installation of additional seedlings mycorrhized in wooded areas where truffles grow naturally. What is meant by controlled truffle is a natural truffle improved with APPROPRIATE cultivation practices and enhanced with the planting of suitable plants and shrubs previously mycorrhized.