The truffle is a fungus which fruiting stage happens underground (hyphae). Its initial stage corresponds to an interlacing of mycelium, whose periphery will close to form the future tuber. It is this external part that will ensure the protection, nutrition and breathing of the truffle. Its growing process lasts several months and depends not only on the type of tree and the soil in which it is located, but also on meteorological factors.
For amateurs, there are only two kinds of truffles: white truffle and black truffle. But there are actually many more. The generic Latin term “tuber” covers perhaps a dozen varieties, but only a few are of interest to the gourmet.
Here is an overview of truffles of gastronomic interest.
Tuber magnatum pico
/also known as White Truffle of Piedmont or Alba.
Tuber magnatum is the one that has the most intense fragrance, with subtle garlic hints. This is why in Piedmont, given its powerful scent, it is forbidden to carry them in public transport.
On the whole, white truffle weighs about 80 grams, but it can reach a kilo or more. It is brownish-white and has a relatively smooth skin (the peridium). The colour of its flesh varies depending on the tree with which it lives in symbiosis. The best tubers are harvested from the roots of oaks and lime trees. We can find it mainly in the Piedmont, Lombardy, Veneto, Tuscany, Molise, Emilia-Romagna and Marche, near Acqualagna, as well as in Croatia.
The annual production is at present only about 25 tonnes, which explains its rarity and its high, even very high price.
It reaches full maturity between the end of October and the end of December.
Tuber melanosporum vittadini
/also known as Black Winter Truffle or Périgord Truffle
When it reaches maturity, it is deep black. Its size varies between that of an egg and of an apple. Externally, it is uniformly sprinkled with small protuberances. Its purple, almost black flesh, is furrowed with very fine white veins. If it has a reddish skin, it means that it is not yet fully ripe.
Its powerful and captivating perfume differentiates it from other truffles. The “Melanosporum” known as the “black diamond of Provence” is also commonly referred to as Perigord Truffle. This appellation is a bit misleading, because 80% of the French production comes from Provence. In France, it also exists in Dordogne, in the Lot and, in general, in the broad South-East. In addition, this species is even more widely-spread in Spain, Italy and the former Yugoslavia. But it can also be found, with very high quality, in New Zealand and Australia. This is interesting for europeans, as “Winter” truffles can be available in Europe in summer.
The harvest period is about three months.
It requires a calcareous, light, crumbly and well-drained soil and plenty of warmth. The winter black truffle lives in symbiosis with the white oak or the holm oak, but also with hazelnut, walnut, plum and maple trees.
Each year the harvest yields about 75 tonnes of winter black truffles. The French truffle, especially from Perigord, fetches the highest prices. In Italy, the main truffle regions are in Umbria (Spoleto, Norcia, l’Aquila) and the Marches (Acqualagna). An large proportion of this production is destined for consumption by the French, keen lovers of winter black truffles.
In Europe, the period of optimal maturity for Melanosporum black truffles lies between mid-December and mid-March. In Australia, this period goes from the beginning of June to the end of August.
Tuber aestivum vittadini
/also known as Summer Truffle or Saint-Jean Truffle
It is the most widespread variety of truffle. It grows in the same type of soil and at the foot of oaks, like melanosporum. In Europe, about a hundred tons are harvested every year. As its name “black summer truffle” suggests , it is during the hot season that collectors scrape the soil to extract this truffle. Beneath its black skin, the flesh is a yellowish beige, with white veining, which allows it sometimes the appellation of white truffle. It is mainly found in Spain, France, Italy and Bulgaria. It is much more advantageous from a price point of view than preceding truffle varieties.
The summer truffle, or “scorzone” in Italian, has a fine and light smell of underwood and a subtle taste of forest mushroom.
Its ripening period is from the beginning of June to mid-September.
Tuber uncinatum
/also known as Autumn Truffle or Burgundy Truffle
It is difficult to distinguish it from the “Tuber Aestivum”, which is why it is sometimes called late summer truffle. In popular usage it is known as “Burgundy truffle”. Compared to the summer truffle, its flesh is brown with beige veins. Its perfume is subtly pleasant and woody, but less pronounced than that of Melanosporum. Tuber uncinatum is also less scarce and less precious too.
It is the most widespread throughout Europe and lives in symbiosis with a wider variety of trees (oak, hazelnut, hornbeam, beech and pine). It is also less demanding in terms of temperature and soil quality.
Up to the Renaissance, this was the only truffle variety to figure on the table of the kings of France. The preference for the Perigord truffle came later, in the reign of King François the Ist.
Some call it “Grey truffle of Burgundy”, but this appellation is misleading, as when mature, the Autumn or Burgundy truffle is black on the outside, with a chocolate brown, veined flesh.
The period of maturity is from mid-September to the end of January.
Tuber macrosporum vittadini
Largely superior in quality to the summer truffle , it yields barely two tonnes a year which means it’s almost unknown in trade. It has a reddish-brown, almost smooth appearance. It is harvested only in the North of Italy and is only found at a few private individuals’ tables.
Tuber albidum pico
Called in Italy simply “Bianchetto” because of its white skin and small size, it is the little sister of the white truffle.
Beware they only resemble the light tone of their skin. Their organoleptic characteristics are totally different. Contrary to the white truffle of Alba, it is recommended to cook it before eating.
It is harvested from spring to early summer in the Emilia-Romagna region, approximately as far as Naples.