Pecorino Romano is the main cheese in traditional cacio e pepe.
The Roman dish’s name means “cheese and pepper” in several central Italian dialects. Its classic ingredients are pasta—often tonnarelli or spaghetti—finely grated Pecorino Romano, black pepper, and a little hot pasta water. The water’s starch helps emulsify the melted cheese into a creamy sauce without cream.
Pecorino Romano is a hard, salty cheese made from sheep’s milk. Although the cheese originated around Lazio, much of its modern production takes place in Sardinia, as well as Lazio and the province of Grosseto. Its strong flavor and firm texture make it especially suitable for grating over pasta.
Cacio e pepe is sometimes prepared with Parmigiano Reggiano, but that is a variation rather than the traditional Roman choice. Mascarpone creates a different, softer sauce, while Gorgonzola changes both the flavor and identity of the dish. The main technical challenge is temperature: excessive heat can make Pecorino Romano clump instead of turning smooth.