Tuber Melanosporum: the Black Truffle
Tuber melanosporum is the scientific name of the black winter truffle, the fungus sold in France as Périgord truffle and in Spain as trufa negra.
It grows underground, attached to the roots of a host tree, and it is harvested from December to April with a trained dog.
Spain is the largest producer in the world at around 120 tonnes a year, against roughly 40 in France, and Teruel accounts for about 80 per cent of world production.
How to recognise Tuber melanosporum
A ripe piece has a black skin covered in small, tight, pyramid-shaped warts. Cut open, the flesh is dark brown with a purple tone, marbled with fine white veins that do not darken in the air.
The aroma is the test. It is penetrating and earthy, and it fills a closed jar within minutes. A piece with no smell is unripe, past its prime, or not the species it claims to be.
| Species | Tuber melanosporum |
|---|---|
| Common names | Black truffle, winter truffle, Périgord truffle, trufa negra |
| Skin | Black, with small pyramid-shaped warts |
| Flesh when cut | Dark purple-brown with fine, branching white veins |
| Season | December to April |
| Where ours grows | Teruel, Spain |
How it grows: a symbiosis with the tree
The fungus and the tree live in symbiosis: each feeds the other. The grower puts it simply: if the tree lacks food, it will not give any to the fungus.
That is why a truffle plantation starts with an inoculated tree, one whose roots already carry the fungus, and why the health of the tree decides the harvest years later.
The truffle is not seen from the surface. A dog trained on its scent marks the exact spot, and the grower opens a small hole with a narrow knife. The dog must not scratch the truffle and the hand must not break it: a split piece is worth a fraction of a whole one.
How Tuber melanosporum is graded in the trade
Grading is by shape and skin, from Extra down to pieces. Extra is round, whole and without cosmetic damage. First and Second are the same truffle with a less regular shape, and pieces are broken truffle with the same aroma.
The price difference between grades reflects the labour of cleaning them, not their flavour.
Winter truffle and summer truffle are two species
Tuber melanosporum is the winter species. Tuber aestivum, the summer truffle, is a different species with a season from May to September, a paler flesh and a much milder aroma.
In the southern hemisphere, Tuber melanosporum is harvested in counter-season. Growers report large yields in Australia and New Zealand; our grower notes he has not seen those plantations himself.
Buy the truffle
Grow the tree
Truffle Trees for Black Truffle (Tuber Melanosporum)
Where an inoculated tree comes from and how many a hectare needs.
Inoculated Truffle Trees: How Black Truffle Mycorrhiza Works
The symbiosis between the fungus and the root, explained by a grower.
How to Grow Black Truffles
Timelines, densities and yields, from a grower.
Is Tuber melanosporum the same as Périgord truffle?
Yes. Périgord truffle is a trade name for the same species. Most of it is now grown in Spain, in Teruel.
When is Tuber melanosporum in season?
From December to April in Spain. Outside those months there is no fresh black truffle from Spain, only preserved and frozen formats.
Can Tuber melanosporum be cooked?
It tolerates gentle heat, unlike white truffle. A short warm-through in butter or a few minutes in a finished sauce holds the aroma. Long boiling and hard frying destroy it.
Why is Spanish black truffle often sold as French?
Because around 90 per cent of the Spanish harvest is exported fresh to France, where it is processed and re-sold. The species is the same.
Buy it from the people who lift it
If you know what you want, the shop page explains grades and how an order is confirmed. If you want to plant it, the truffle trees page explains where the plant comes from.