Truffles are a particular type of fungus that arises spontaneously in the woods and develops underground, at a depth ranging from a few to a maximum of 40-50 cm below ground, in correspondence with root systems of different types of plants such as oaks, hazels, poplars, willows, beeches, and pines.
Truffles look like tubers, and based on a series of factors they can be black-brown or brown-yellow, of fairly regular or irregular round shape, and of sizes ranging from a diameter of a few cm to a maximum of about 15 cm.
The external part, the so-called peridium, depending on the type of truffle, can be brown (between black and dark brown) or light brown to yellow. The peridium may have a smooth surface (especially for white truffles which, despite the name, are in fact light brown-yellow) or more or less warty.
The inner part, inseparable from the peridium, is called the gleba. The gleba can take on very different shades: from hazelnut to light brown, from dark brown to purplish, often with lighter colored veins.
There are dozens of truffle species in the world, but the most valuable types are reduced to a few units and their production is limited to Europe, especially Italy, France and Spain and surrounding countries. Italy boasts the record for producing the most precious and flavourful truffle that is the white truffle of Alba or white truffle of Acqualagna. Alba is a small town in northern Italy in the Piedmontese Langhe, also famous for the production of fine red wines such as Barolo and Nebbiolo. Acqualagna is an even smaller town in central Italy in the Marche region on the border with Umbria.