White truffle

The white truffle is the fruiting body of a fungus that lives symbiotically on the roots of oak, poplar, willow and lime, underground, anywhere from a few centimetres to half a metre down. There is only one species and no commercial varieties. What varies is the soil, the host tree and the year.

What makes it unique is that nobody has managed to farm it at scale. The prized black truffle has been cultivated since the late nineteenth century using inoculated saplings; the white one has resisted every attempt. Managed truffle grounds exist, where natural production is encouraged, but the harvest is still a hunt rather than a crop.

Everything else follows from that: the price, the four-month season, the way quotations swing by a factor of two between vintages, and the fact that the white truffle trade is one of the most fraud-prone corners of Italian food.

Overwhelming and not conventionally pleasant up close: garlic, aged cheese, wet hay, methane, and something animal underneath. It is a smell more than a flavour: the actual taste on the tongue is mild and faintly earthy, and almost all of the experience happens in your nose.

On a warm plate the aroma rises in a wave that fills the room within seconds and fades within minutes. That decay is the whole reason for the ritual around it: shaved at the table, eaten immediately, never held.

If you have only met truffle through truffle oil, truffle fries or truffle mayonnaise, prepare for a shock. Those products taste of one loud synthetic molecule; the real thing is layered, shifting and far less aggressive, and it does not leave the metallic aftertaste that manufactured truffle flavour does.

Never apply heat. Shave the truffle raw, with a proper truffle slicer set thin, over a plate that is already hot: the residual warmth is all that is needed to release the aroma. Do it at the table, and eat within a minute or two.

The four traditional dishes are all deliberately bland underneath. Tajarin, the thirty-yolk Piedmontese egg pasta, dressed with nothing but butter. A fried or coddled egg. Fonduta, the Valle d'Aosta fontina custard. Carne cruda all'albese, hand-chopped raw veal with oil and lemon. In every case the dish exists to provide fat and heat, nothing else.

Budget 5 to 8 grams per person. A 40-gram truffle serves five or six. That is why restaurants price by the gram, and why an honest portion runs 20 to 40 dollars.

Strip the plate of competing aromatics: no garlic, no fresh herbs, no lemon, no vinegar, no pepper. And if you are making risotto, shave the truffle over the finished plate, never stir it into the pan.

A white truffle is at its peak the day it comes out of the ground and loses aroma from then on: dealers reckon on roughly 5 percent of its weight lost per day to evaporation, and the perfume goes with it. Plan to use it within three to five days of buying, which is why it is bought by the gram for a specific dinner rather than kept. Store it in the fridge, in a sealed glass jar lined with kitchen paper, and change that paper every day as it takes up moisture.

Never wash it before storing: brush the soil off dry, only at the moment of use. Rice is the classic container and a poor one, because rice pulls water out of the truffle and dries it while flavouring the rice. Over a few days the surface shrinks and wrinkles, the flesh softens, and the aroma flattens from pungent to faintly mushroomy. Freezing preserves nothing worth having: the texture collapses on thawing and the volatile compounds are gone. Eggs stored beside it in the same jar do absorb the perfume through the shell.

Tuber magnatum pico is irregular and lumpy rather than round, with a smooth, thin, pale skin somewhere between cream and ochre, and it should feel firm and heavy for its size when you press it. Cut, the interior is pale beige to pinkish brown, marbled with fine white veins. The aroma does the identifying: it carries across a room, garlic and cheese and damp hay all at once, and it is nothing like the single dimensional smell of truffle oil, which is a synthetic molecule and contains no truffle.

Season is the cheapest test available. The Alba truffle runs from late September to the end of January; anything sold as white truffle in June is bianchetto, Tuber borchii, a different and far cheaper species that is smaller, harsher and more aggressively garlicky. Price is the other test: magnatum trades at roughly $2 to $6 per gram depending on the year, so a whole one is weighed in front of you on a certified scale and comes with its harvest area stated. Anything offered at supermarket money is a different species with a borrowed name.

In the US, fresh white truffle arrives by air freight between late October and December from a small number of importers (Urbani, Sabatino, Gustiamo and a handful of specialists) at roughly 150 to 350 dollars per ounce depending on the vintage and the size of the piece. Order it timed to a specific dinner: it is five or six days from dug to worthless.

In the UK, the Italian delicatessens of Soho and Clerkenwell and the specialist fungi suppliers who serve restaurants sell to the public in season, at around 3 to 6 pounds per gram. Some will hold a piece for a named date, which is the right way to buy it.

Buy by weight, in person if you can, with the truffle on the scale in front of you. Ask for the species in writing, the region and the harvest date, and ask them to brush the soil off before weighing. Firm as a raw potato, heavy for its size, smooth ochre skin, beige-pink interior with fine white veins, and an aroma that reaches you across the counter. If any of those fail, walk away. A suspiciously low price is not a bargain but a different species.

Alba, in the Langhe, from mid-October to early December. The World Truffle Market in the Cortile della Maddalena runs at weekends and is the only place where you can see a hundred truffles side by side and learn to tell them apart. Trattorie in Alba and in the wine villages (La Morra, Barolo, Serralunga, Monforte) post the per-gram price on the menu.

Acqualagna, in the Marche, holds its national fair from late October into November and is far less touristed. The truffles are the same species and often the same quality; the bill is not.

San Miniato in Tuscany runs market weekends through November and has produced some of the largest specimens on record. San Pietro Avellana in Molise and Savigno in the Bolognese Apennines offer the same thing without the crowds.

The experience worth paying for anywhere is a dawn hunt with a trifolau and his Lagotto Romagnolo: two hours, 40 to 120 euro per person, and more education than any fair provides.