Piedmont Hazelnut

Nocciola Piemonte is a protected geographical indication, registered in 1993, covering the Tonda Gentile Trilobata cultivar, historically Tonda Gentile delle Langhe, grown in the hill country of Piedmont.

A single variety, which already sets it apart from most of the world market. The nut is spherical, medium in size, with a thin pale shell, and three of its qualities are the ones that matter commercially.

First, kernel yield: 40 to 50 per cent, against 30 to 40 for average commercial hazelnuts. A kilo in shell gives close to half a kilo of nut.

Second, peelability. After roasting, the perisperm, the papery skin, comes away almost completely with a rub in a tea towel. It sounds like a laboratory detail and it is in fact the economic reason confectioners chase this nut: skin that clings leaves bitter fragments and speckles a smooth cream.

Third, aroma: fine, persistent, buttery, with a sweetness that does not tire and a crisp structure that survives baking. Add unusually stable fats, which matter in a fruit that is more than 60 per cent oil, and the result is a nut with a longer shelf life than most.

Sweet, buttery and clean, with a toasted note that arrives without any bitterness behind it. Raw, it is milder and milkier than most people expect; roasted, it turns intensely aromatic, almost like browned butter, and stays crisp rather than waxy.

The absence of bitterness is the tell. Cheap or badly roasted hazelnuts carry an astringent edge from the skin that clings to them; a properly roasted Tonda Gentile sheds its skin and tastes uniformly sweet.

Hazelnut paste made from it is pale beige, thick and glossy, and tastes of nothing but nut. Set it next to a supermarket chocolate spread and the difference is not subtle: one tastes of hazelnut, the other of sugar and vegetable oil with hazelnut somewhere in the background.

Roasting decides everything. Oven at 150°C for twenty to twenty-five minutes, turning once, until the skins crack and the kitchen smells of them. Then tip them into a tea towel and rub. Above about 170°C they turn bitter within minutes, so stay low and trust your nose.

The Langhe hazelnut cake is the defining dessert: roasted nuts ground to flour, eggs, sugar, butter and little or no wheat flour. It is low, moist and served with warm zabaione.

Baci di dama are two hazelnut-paste domes joined with chocolate; brutti ma buoni are rustic meringues studded with nuts; nocciolini di Chivasso are tiny and weightless. The gianduiotto is hazelnut paste and cocoa, moulded into an ingot.

Savoury uses are underrated: coarsely chopped over raw Fassona beef, on blue cheese, in a pumpkin or Jerusalem artichoke soup, and in hazelnut pesto tossed through tajarin, cheaper than pine nuts and more robust.

Grind in short pulses. Hazelnuts are over 60 per cent fat and go from flour to butter in seconds; if you need dry flour, add a spoonful of the sugar from the recipe.

A hazelnut is more than sixty per cent fat by weight, and that oil is what changes over time. In shell they are the most stable form: an open bowl away from light, in a cool dry room, holds eight to twelve months. Shelled and raw they drop to four to six months in a closed glass jar in the cool, and stretch to about eight in the fridge. Roasted, they are the most fragile of all, two to four weeks at room temperature in a sealed jar, since roasting builds the aroma and speeds up oxidation at the same time.

The freezer handles quantity: vacuum sealed or in a well closed bag, shelled kernels hold about a year and go straight into a recipe without thawing. What to avoid is the shelf above the hob, bags left open and direct light. A paint like or stale note on tasting means the oil has oxidised, and it comes through more strongly in a dessert than out of hand. Opened hazelnut paste goes in the fridge for around a month; oil separating on top is normal and stirs back in.

Shape is the first clue. The Tonda Gentile is round, not oval and not pointed, with a faint three lobed look to the shelled kernel; the long, tapered nuts in most British and American bins are Oregon filberts or Turkish varieties. The label has to read Nocciola Piemonte IGP or Nocciola del Piemonte IGP with the European logo beside it. Langhe hazelnut, Italian hazelnut and Piedmont type hazelnut are not the denomination.

Two tests settle it at home. Roast a handful at 150 °C for twenty minutes, wrap them in a tea towel and rub: on a Tonda Gentile almost all the skin comes away, and if it clings to half the kernels it is another variety. Bought in shell, a kilo should yield 400 to 500 g of kernel, and under 350 g points elsewhere. On the tongue a good hazelnut is sweet, buttery and crisp with no bitter finish. For spreads, look for the hazelnut percentage next to the ingredient: many jars declare 13 per cent or less, with palm oil and sugar doing the rest, while a serious one starts at 40.

Italian specialists are the route: Gustiamo and Eataly in the US, Sous Chef and Italian delicatessens in the UK, and many Langhe producers ship directly. Pastry suppliers sell 100 per cent hazelnut paste and hazelnut flour as well as whole kernels.

The label should read Nocciola Piemonte IGP or Nocciola del Piemonte IGP with the EU mark. Hazelnuts from the Langhe, Italian hazelnuts and Piedmont-style are not the designation.

Buy raw and roast them yourself if you can: roasted nuts have a shelf life of weeks, raw ones of months. In shell, they keep longest of all and are the cheapest way in.

Expect 18 to 30 euros a kilo shelled in Italy, 16 to 28 dollars a pound in the US and 28 to 50 pounds a kilo in the UK; in shell, 6 to 10 euros a kilo. For spreads, read the percentage printed beside the ingredient rather than the name on the front of the jar: a serious cream is 40 per cent hazelnut or more.

Cortemilia, in the Alta Langa, is the capital of the nut and holds its hazelnut fair in August. The hillsides there are planted at gradients that explain the price on their own, and producers sell direct.

Alba, half an hour away, is where the nut becomes pastry: cakes, baci di dama, pure pastes and creams in every second shop window. In autumn the town belongs to the white truffle fair, and the two things share the same counters.

Turin is the chocolate chapter: historic chocolatiers in the centre, bicerin in the old cafés, gianduiotti everywhere, and pastry shops making nocciolini and baci di dama.

Across the Roero and Monferrato, farms run hazelnut grove visits and tastings, often paired with wine. September, during the harvest, is the moment to go: the sweepers work under the trees and you finally see why nobody picks hazelnuts off the branch.