Never eat a wild mushroom identified only from a website, a book or an app. Have every find checked in person by an expert, such as a mycological society.
Identification
The white truffle has an irregular, often lumpy fruit body 2–12 cm across, with a smooth skin without warts, pale ochre, cream or slightly greenish yellow in colour. The flesh is firm, cream to hazel or reddish brown, marbled with fine white veins. Its aroma is extraordinarily strong and complex, often described as garlicky, cheesy and honey-like. Under the microscope the spores are yellow-brown, ellipsoid and covered with a coarse, net-like ornament, usually 1–4 per ascus.
Smooth pale skin and intense smell separate it from the cheaper Tuber borchii (bianchetto or whitish truffle), which ripens in late winter and spring and has a sharper, more garlicky smell.
Habitat and ecology
Tuber magnatum is ectomycorrhizal with poplars, willows, oaks, lime trees and hazel. It needs loose, well-aerated, moist, calcareous to neutral soils, typically in valley bottoms, along streams and in damp woodland. Its natural range is mainly Italy (Piedmont, Tuscany, Marche, Umbria, Molise and other regions) and the Balkan Peninsula, including Croatia, Slovenia, Serbia and Hungary; it is found more rarely in Switzerland and south-eastern France. Fruit bodies ripen in autumn and early winter.
Uses and importance
White truffle is almost never cooked. It is shaved raw in thin slices over warm, simple dishes, such as fresh egg pasta (tajarin), risotto, fried eggs, fondue or carpaccio, just before serving, so that the heat releases its aroma. It loses its scent within days and should be kept cool, wrapped in paper, and used quickly. Most "white truffle oil" is flavoured with synthetic aroma compounds, not with real truffle. Famous markets include the white truffle fair of Alba in Piedmont.
Cultivation
White truffle cultivation has long been considered impossible. INRAE in France reported in 2021 that truffles were harvested in 2019 and 2020 from a young orchard of inoculated trees in Nouvelle-Aquitaine, outside the natural range, which was presented as a world first. Production in plantations is still experimental and small compared with wild harvests. Inoculated seedlings are available, but site requirements (moist, well-aerated soils and suitable climate) are demanding and success is uncertain.
Safety and edibility
The white truffle is a safe edible when genuine and fresh. The main risks are fraud and confusion with cheaper or inedible underground fungi. If you find truffle-like fungi yourself, identification must be confirmed in person by an expert, such as a mycological society or truffle specialist. Choiromyces meandriformis, a pale underground fungus sometimes called the false white truffle, is considered toxic or indigestible, and earthballs (Scleroderma citrinum) are toxic. In Italy, truffle hunting is regulated by national law and regional rules.
If you suspect mushroom poisoning, call 999 in an emergency or NHS 111 for urgent advice straight away, even before symptoms appear, and keep the remains of the mushrooms.
Look-alikes
Tuber borchii (bianchetto) has a smooth pale skin too but a darker, reddish flesh in maturity, a sharper smell and a different season (late winter to spring). Choiromyces meandriformis is pale yellowish with meandering, labyrinth-like veins and a strong, unpleasant smell. Scleroderma citrinum (common earthball) has a hard, yellowish, scaly skin and purplish-black flesh. Spore microscopy and an expert's nose are the reliable tests.
In the UK
The white truffle does not grow wild in the UK; its natural range is centred on Italy and the Balkans. British restaurants and food shops import it in autumn and early winter, when it can sell for several thousand pounds per kilo.
The truffle native to Britain is the summer or Burgundy truffle (Tuber aestivum). Products labelled with ‘white truffle’ flavour, such as many truffle oils, often contain synthetic aroma compounds rather than truffle, so check the ingredients.
