Pecorino Romano vs Parmesan: Cow vs Sheep, Salt and When to Use Each

The rest of the story is rennet, salt and age, and together they decide what each cheese does to a dish. The Pecorino Romano guide and the Parmigiano-Reggiano guide cover each cheese in full; this page is for the moment you are standing at the grater and have to pick one.

Pecorino Romano vs Parmesan at a glance

This Pecorino Romano vs Parmesan table sets the two PDO cheeses side by side, with USDA's numbers for one ounce.

Why Pecorino Romano and Parmesan taste different

Pecorino Romano and Parmesan taste different for three reasons: the milk, the rennet and the salt.

USDA lists sheep's milk at 7.0 grams of fat and 6.0 grams of protein per 100 grams, about double whole cow's milk at 3.3 and 3.2, so twice the fat and protein go into the vat before the cheesemaker does anything (the sheep vs goat vs cow guide covers the milks). The rennet differs too. Pecorino Romano is set with lamb rennet paste, which carries a fat-splitting enzyme; in a study of a goat cheese, the paste raised short-chain fatty acids and gave a slightly more piquant taste. Parmigiano-Reggiano allows only calf rennet and is soaked in saturated brine, while Pecorino Romano is salted dry, in brine or both, and can be sold after 5 or 8 months.

The two rulebooks put the result in words. Pecorino Romano's is aromatic and mildly pungent as a table cheese and pungent and intense when well aged; Parmigiano-Reggiano's is fragrant and delicate, flavorful without being strong.

Pecorino vs Parmesan salt

Pecorino vs Parmesan salt is easy to measure: USDA's Romano row has 406 mg of sodium per ounce against 333 mg for hard Parmesan, about 22 percent more.

The Italian PDO can run higher still. A 2024 study of 103 Sardinian Pecorino Romano samples puts typical salt at 3 to 7 percent, and the EU rules set a salt cap only for the new Riserva type, at 4 percent. USDA's hard Parmesan works out to about 3 percent salt (1,175 mg of sodium per 100 grams, converted). Calories are nearly identical, 110 and 111 an ounce, while Parmesan has more protein (10.1 grams to 9.0) and calcium (336 mg to 302).

When to use Pecorino Romano and when to use Parmesan

Use Pecorino Romano when you want salt and bite to be the flavor, and Parmesan when you want savory depth that stays in the background.

Rome's four classics, cacio e pepe, gricia, amatriciana and carbonara, are built on Pecorino, because the cheese is half the seasoning. Risotto, cream sauces, soups, meatballs and baked pasta are Parmesan's territory, and the risotto guide shows how it finishes a pot. For a board, shave a young Parmigiano-Reggiano or slice a 5-month Pecorino Romano with pears and honey. A half-and-half blend is a common compromise when a recipe wants Pecorino's bite with Parmesan's roundness.

How to tell Pecorino Romano from Parmesan at the cheese counter

To tell Pecorino Romano from Parmesan at the cheese counter, look at the wheel shape and the rind.

A Pecorino Romano wheel is a tall cylinder, 10 to 14 inches across and 10 to 16 inches high, with a thin ivory rind that may be coated black or brown and a stamped diamond holding a sheep's head. A Parmigiano-Reggiano wheel is squatter, 14 to 17 inches across and 8 to 10 inches high, with dotted lettering around its straw-colored side. Cut open, Pecorino Romano's paste runs from white to straw and may show a few small holes, while Parmigiano-Reggiano's is light straw and finely grained.

Pecorino Romano and Parmesan substitutes

The best way to swap Pecorino Romano and Parmesan is to adjust the amount and the salt, because the cheeses are not equal in strength.

These amounts are starting points, not rules. The substitute finder lists swaps for both.

What most Pecorino Romano vs Parmesan advice gets wrong

Most Pecorino Romano vs Parmesan advice compares the names, and two details make that misleading.

Pecorino is not always the stronger cheese

Pecorino is not always the stronger cheese, because age matters as much as milk. A 5-month table Pecorino Romano is only mildly pungent, while Parmigiano-Reggiano of 27 months or more is described by its consortium as pronounced, with spice and nuts, so compare wedges of similar age.

Cow against sheep is not guaranteed in the US

Cow against sheep is not guaranteed in the US, because the federal standard for Romano allows cow's, sheep's or goat's milk, with at least 38 percent milkfat in the solids and 5 months of curing. The standard for Parmesan is cow's milk only, 10 months, at least 32 percent milkfat. Read the label for sheep's milk, and see what Parmesan means in the US for the rest.

Questions about Pecorino Romano vs Parmesan

These questions about Pecorino Romano vs Parmesan come up most at the stove.

What is the difference between Pecorino Romano and Parmesan?

The difference between Pecorino Romano and Parmesan is the milk and the intensity: Pecorino is sheep's milk, saltier and sharper, while Parmesan is cow's milk, nuttier and rounder.

Can you substitute Parmesan for Pecorino Romano?

You can substitute Parmesan for Pecorino Romano at the same weight, adding a pinch of salt and pepper, but the result will be milder and less tangy.

Can you substitute Pecorino Romano for Parmesan?

You can substitute Pecorino Romano for Parmesan by using about three-quarters as much and cutting the other salt in the dish.

Which has less sodium, Parmesan or Pecorino Romano?

Parmesan has less sodium: USDA lists 333 mg an ounce for hard Parmesan and 406 mg for Romano.

Is Pecorino Romano or Parmesan better for carbonara?

Pecorino Romano is the traditional cheese for carbonara, and a blend of the two is a common way to soften its edge.

Is Pecorino Romano or Parmesan lactose free?

Pecorino Romano and Parmesan are both close to lactose free: a 2020 review lists Parmigiano-Reggiano and Pecorino Romano at under 0.01 gram of lactose per 100 grams, though both still contain milk protein.

Pecorino Romano or Parmesan: what to buy

Buy both in small wedges: a Pecorino Romano with the sheep's-head mark for the Roman pastas and a Parmigiano-Reggiano of about 24 months for everything else. Taste a sliver of each plain, then you will know which one a recipe needs.