The lagoons of Cabras and Santa Gilla in Sardinia — grey mullet have been farmed in the coastal lagoons of Sardinia since Phoenician times. The technique of pressing and drying roe sacs is ancient; the Sardinian product is documented in records going back at least to the 14th century.
Bottarga is the preserved, pressed, and dried roe sac of the grey mullet (Mugil cephalus) — the most prized seafood product of Sardinia and a flavour of extraordinary depth. The intact roe sac is removed from the fish in September-October when the females are at their prime, coated in sea salt, pressed under weighted boards for several weeks to extract moisture, then air-dried for 2-4 months until it is firm, golden-amber, and completely dry. The result is grated or sliced thin and used as a condiment — a little goes an enormous way.
Mullet bottarga grated fresh has a complex, layered flavour — intense oceanic umami, a sweet-saline quality from the mullet's fat, and a subtle bitterness from the membrane. Nothing about it is simply 'fishy'. On warm pasta with olive oil, the bottarga dissolves slightly and its flavour permeates every strand. The taste lingers on the palate for several minutes.
The integrity of the roe sac is essential — any tear during extraction ruins the product. The pressing under salt and weight must be gentle but consistent, rotating the sac to ensure even drying. The drying stage must be in well-ventilated, cool conditions (12-16°C) away from direct sun — direct sun creates rancidity. The finished bottarga should be firm throughout with no soft spots (sign of incomplete drying), amber-gold in colour, and should smell of the sea but not of fish oil. Two principal types: muggine (mullet — the Sardinian benchmark) and tonno (tuna — larger, stronger, less refined).
Mullet bottarga is at its best grated directly over warm pasta or toast immediately before eating — within seconds of grating. The volatile aromatics dissipate quickly; pre-grated bottarga is a fraction of the value. Store in the refrigerator wrapped in clingfilm (or vacuum-sealed) and use within 6 months of opening. Thinly sliced bottarga dressed with lemon and olive oil is the Cagliari classic antipasto.
Purchasing bottarga that smells strongly of rancid fish — a sign of improper drying or storage. Grating bottarga too thick — it should be paper-thin for service as a condiment; thick pieces are astringent. Not removing the waxy film before grating — the outer wax coating preserves the bottarga but must be peeled back before use. Applying heat to mullet bottarga — heat destroys its delicate flavour; only tuna bottarga is used in cooking.
Paul Bertolli, Cooking by Hand; Giorgio Locatelli, Made in Italy