Bottarga di muggine is Sardinia's 'gold of the sea'—the salted, pressed, and sun-dried roe sac of the grey mullet (muggine/cefalo), producing an amber-coloured, firm, waxy block that is grated or thinly sliced over pasta, bread, and salads to deliver an intensely concentrated, briny, umami-rich flavour that is one of Italian cuisine's most prized ingredients. The finest bottarga comes from Cabras and the lagoons of the Sinis peninsula in western Sardinia, where grey mullet are caught as they enter the brackish coastal ponds (stagni) in late summer to spawn. The intact roe sacs are carefully extracted (any puncture is ruinous), salted for several weeks in sea salt, then pressed under weights to remove moisture and flatten them, and finally hung to air-dry for several months until firm, translucent, and deep amber-gold. The resulting product is an intensely concentrated flavour bomb: briny, fishy (in the best possible sense), slightly sweet, with a waxy, firm texture that can be shaved with a mandoline or grated on a microplane. The most classic Sardinian preparation is spaghetti con la bottarga—al dente spaghetti tossed with olive oil, a hint of garlic, minced fresh parsley, a touch of chilli, and a generous grating of bottarga added off the heat so it doesn't cook (heat makes it bitter and rubbery). Bottarga is also shaved paper-thin over sliced fresh artichokes, celery salad, or simply eaten as slices on buttered bread. Quality varies enormously: artisanal Sardinian bottarga from Cabras is an entirely different product from industrial or imported versions.
Grey mullet roe sac, salted, pressed, sun-dried for months. Amber-gold, firm, waxy texture. Grate or shave thin—never cook (heat ruins it). Classic with spaghetti: olive oil, garlic, parsley, bottarga off the heat. The best comes from Cabras, Sardinia. An umami concentrate.
Store whole bottarga vacuum-sealed in the fridge—it keeps for months. Grate it on a microplane for the finest, most uniform distribution. For spaghetti con bottarga, the pasta should be dressed only with excellent olive oil, with the bottarga grated over each plate at the table. A squeeze of lemon brightens it wonderfully. The wax coating on commercial bottarga should be peeled before use.
Cooking bottarga (it turns bitter and rubbery with heat—add it off the flame). Using too much (it's intensely concentrated—a little goes far). Buying low-quality or imported bottarga (artisanal Sardinian is incomparably better). Slicing too thick (paper-thin shavings or fine gratings are ideal). Confusing with bottarga di tonno (tuna bottarga—darker, stronger, different product).
Giovanni Ferrua, Traditional Recipes of Sardinia; Touring Club Italiano, Sardegna in Cucina