What is the difference between Parmigiano Reggiano and Grana Padano?

Side by side on a board, they look like siblings. They are made in similar ways, both have that crumbly, crystalline texture, and both are grated over pasta from one end of Italy to the other. The differences are in the rules each consortium sets, and those rules show up in the flavour.

Where they come from

Parmigiano Reggiano can only be made in a small, defined area: according to the Parmigiano Reggiano consortium, the provinces of Parma, Reggio Emilia and Modena, plus Bologna west of the Reno river and Mantua south of the Po. Every step of production happens there.

Grana Padano covers a far bigger stretch of the Po valley. The Grana Padano consortium lists 32 provinces across Piedmont, Lombardy, Veneto, Emilia-Romagna and Trentino-South Tyrol.

How they are made

The main differences, as each consortium describes them:

• Ingredients. Parmigiano Reggiano is made only from milk, salt and rennet, with no additives or preservatives, per its consortium.
• The cows' feed. Silage is not allowed for Parmigiano Reggiano. Grana Padano permits it, and so may add lysozyme, an egg-derived protein, to prevent unwanted fermentation, according to the Grana Padano consortium. If you are cooking for someone who avoids egg, check the label.
• The milk. Both use partly skimmed milk, skimmed in slightly different ways, which the Grana Padano consortium explains on the same page.
• Ageing. Parmigiano Reggiano's minimum is twelve months, and the consortium says most of what is sold is aged 24 to 36 months. Grana Padano is inspected and branded from nine months, with a Riserva category for wheels aged over 20 months.

One more naming note: within the EU, "Parmesan" is treated as evoking Parmigiano Reggiano, which the consortium explains followed a 2008 European Court of Justice ruling. Outside Europe, "parmesan" on a label can mean something else entirely.

How they taste

Age changes everything, so compare like with like. In broad strokes:

• Young Grana Padano is mild, milky and slightly soft, with a gentle saltiness. It melts easily and doesn't dominate.
• Parmigiano Reggiano at around two years is drier and more crumbly, with more crystals, a nutty, savoury depth and a longer finish.
• Older wheels of either become sharper, more granular and more intense.

Neither is "better". They are different tools.

When the choice matters at the stove

Reach for Grana Padano when:

• You want a gentle cheese in a filling, like a ricotta stuffing for pasta or vegetables.
• It's going into a béchamel, a gratin, or a baked dish where it will melt into the background.
• You are grating generously over everyday pasta and want something mellow.

Reach for Parmigiano Reggiano when:

• The cheese is a main flavour, as in risotto finished with butter and cheese, or pasta with butter and cheese.
• You are serving it in chunks, with pears, a drop of balsamic, or as part of an aperitivo.
• You want a rind to simmer in a soup; both rinds work, but Parmigiano's is especially savoury (see Parmesan rinds).

Either is fine for most weeknight grating. Use what you have.

Pecorino is another question altogether, made from sheep's milk; Pecorino or Parmesan covers it.

Buying and storing

Look for the name stamped or dotted into the rind, and the age on the label. A piece cut from the wheel keeps better than pre-grated cheese and tastes fresher when grated just before eating. Wrap it in waxed paper or baking paper and then loosely in a bag, in the fridge. Cling film suffocates it and makes it sweat.