What Cheese Is In Pesto?

Traditional basil pesto contains two cheeses, Parmigiano-Reggiano and Pecorino Sardo. However, many producers chase cost savings by using alternative cheeses.

Only pesto containing two specific cheeses is considered authentic

The official basil pesto recipe dictated by the organisers of the World Pesto Championships states that authentic pesto must contain both Parmigiano-Reggiano and Pecorino Sardo. They say the sauce can no longer be considered pesto if you use an alternative cheese.

Parmigiano-Reggiano and its role in pesto

Known as the "King of Cheeses," Parmigiano-Reggiano is a hard cheese made from cow's milk that is aged for a minimum of 2 years. It brings a profoundly savoury and nutty complexity to pesto, which balances the basil's freshness and the raw garlic's pungency.

Parmigiano-Reggiano is protected by law

Parmigiano-Reggiano has a protected designation of origin (PDO) status, which means it can only be produced in a specified area, using exact ingredients and following a specific production and ageing process. Even the cattle that provide the milk must be fed a particular diet. You can tell you have the real deal because the packaging will contain the PDO logo.

Is Parmigiano-Reggiano just a fancy name for parmesan?

The PDO status only applies within the EU, meaning that in the US and elsewhere, the generic term "parmesan" is commonly used to describe cheeses that mimic Parmigiano-Reggiano. Cheese connoisseurs can quickly tell the difference because parmesan is not aged for as long. For most people, however, parmesan is so close to the real deal that once it is added to pesto, it's almost impossible to tell the difference.

Modena in northern Italy is most famous for being the home of the Italian supercar, with Ferrari, Lamborghini, and Maserati all based there. It is also one of the few places (alongside Parma, Reggio Emilia, Modena, Mantua, and Bologna) where Parmigiano-Reggiano can legally be produced.

On a recent visit to Modena, we got to try some 8-year-old Parmigiano-Reggiano. This extended ageing process produces a complex cheese with many little white crystals that crunch when you bite into it. These crystals are of the amino acid tyrosine, and while they don't contribute much flavour, they provide the telltale crunch that the cheese has been well-aged.

Amino acids are also responsible for Parmigiano-Reggiano's high level of naturally occurring glutamates. These acids are the foundation of industrially produced monosodium glutamate (MSG), which is why this cheese is considered the world's most umami ingredient, second only to soy sauce.

Authentic pesto also contains Pecorino

Pecorino is a hard cheese made from sheep's milk. There are many different types of Pecorino (including Toscano, Siciliano and Filiano). Pecorino Romano is the one that you will most commonly find on the shelves of UK supermarkets. That's a shame because the official pesto recipe calls for Pecorino Sardo, which is much harder to track down.

Hailing from Sardinia, Pecorino Sardo is typically more assertive than parmesan. It has a vibrant and slightly tangy taste. It is bolder and saltier, with a sharper, earthier flavour profile. For this reason, it is most often used in slightly smaller quantities than Parmigiano-Reggiano when making pesto.

Other cheeses used in pesto-making

Aged cheeses are naturally expensive, so many pesto producers opt for alternatives. Grana Padano is the most popular substitute for Parmigiano-Reggiano and Pecorino, which is not to say it isn't a top-quality cheese. Instead, it has much less stringent regulations than the other two, making it significantly more affordable.

In some parts of Italy, locals add ricotta to their pesto. This gives the sauce a creamier and more luxurious feel, and while traditionalists won't be seen dead eating it, we must admit to rather liking it. Pesto giants Sacla and Filippo Berio have ricotta pestos in their sauce portfolio, and De Cecco produces a mascarpone pesto.

Traditional 'rules' regarding what is and isn't allowed in pesto are irrelevant when you're making it at home. A quick online search reveals many pesto recipes made with every kind of cheese imaginable.

Pesto beyond cheese

A brief look at the ingredient list on the label of a shop-bought pesto gives away lots of clues about behind-the-scenes cost savings. For example, you'll often find pine nuts replaced with cashews and olive oil replaced with sunflower oil. When you see "whey powder" on the ingredient list, you can be sure the producers are trying to replicate the creamy quality of cheese without using as much of the real thing.

Although vegan cheeses are now readily available, most vegan pesto producers tend to ditch the cheese entirely and substitute nutritional yeast, which naturally has a cheesy, savoury flavour.