Valle d'Aosta — the smallest region of Italy, flanked by Mont Blanc, the Matterhorn, and the Gran Paradiso. The Fontina cheese has been produced in this valley since at least the 13th century; the fonduta preparation is documented from the medieval period.
Fonduta valdostana is the definitive preparation of Fontina DOP — the great, fat, semi-soft Alpine cheese of the Valle d'Aosta, whose PDO specifications confine production to this single valley. Unlike Swiss fondue (which uses a blend of hard cheeses, white wine, and Kirsch), the Valdostan fonduta is made with Fontina alone, soaked in milk, then melted slowly with egg yolks and butter into a rich, unctuous, truffle-scented sauce. It is served in a fondue pot or cazuela, poured over polenta, bread, or alongside crudités. The result is deeper, richer, and more savoury than any Swiss preparation — a statement of one cheese's character rather than a blend.
Fontina fonduta is one of the richest flavour experiences in Italian cooking: deeply savoury, buttery, with the characteristic mild sweetness and slight earthiness of Fontina — a cheese that tastes of the high Alpine meadows where the Valdostan cows graze. The egg yolks add depth; the white truffle, when present, takes it somewhere transcendent.
The technique hinges on the Fontina preparation: cut the Fontina into small cubes (rind removed), cover entirely with whole milk, and refrigerate for a minimum of 4 hours (overnight preferred) — this softening allows the cheese to melt without graining. When ready, drain the milk (reserving it), melt butter in a bain-marie over barely simmering water, add the softened Fontina and the reserved milk, and stir continuously with a wooden spoon until the cheese melts completely into a smooth, uniform cream — 15-20 minutes. Remove from heat, stir in egg yolks (2 per 200g Fontina) one at a time, whisking vigorously. Return briefly to bain-marie only if needed to reheat. Season with white pepper only — the Fontina is already salty. Serve immediately, shaved black truffle optional.
The white truffle of Piedmont, grated over fonduta at service, is one of the great combinations in Italian cooking. The fat content of Fontina DOP (minimum 45% in dry matter) is the reason the fonduta is possible — it melts without separating. The egg yolks add richness but also act as a temporary emulsifier; the fonduta must be served immediately or it will set. A copper or earthenware pot holds heat longest at service.
Not soaking the Fontina in milk — the milk pre-hydration is what prevents the cheese from seizing and graining during melting. Too-high heat — the eggs scramble and the cheese proteins denature; bain-marie is mandatory. Using Fontina Svizzera or any Fontina outside the DOP — only Val d'Aosta Fontina DOP has the fat content and flavour profile required. Adding wine — this is not Swiss fondue; wine acidifies the cheese and changes the character entirely.
Giorgio Locatelli, Made in Italy; Marcella Hazan, Essentials of Classic Italian Cooking