Tuber melanosporum, the Périgord truffle: black and warty outside, dark and finely marbled within, with a musky, earthy scent that wakes up with gentle heat and fat.
earthy · musky · cocoa-like
Kinds
Périgord / winter black
The real thing — near-black inside with fine white veins, and the strongest scent.
Summer truffle (Tuber aestivum)
May to August; pale brown inside and far milder. Cheaper, so use it generously.
Burgundy truffle
The autumn form of the summer truffle — darker and more aromatic.
If you can't find it
Specialist shops, in season — and expensive.
1Truffle paste
A little, at the end
You lose most of it. Most truffle oil is synthetic; use it rarely, if at all.
From truffle merchants and good delis, by the gram: firm, heavy, and smelling strongly through the paper. Much of the crop now comes from Spain as well as France and Italy. Truffle oil is almost always synthetic flavouring.
Worth knowing
Store it in a sealed jar with eggs in their shells or dry rice for a day or two — the scent moves into them. Unlike white truffle it likes a little warmth: grate it into hot butter or a sauce, or slip slices under chicken skin before roasting. Never cook it hard.