Researchers Have the Perfect Cacio e Pepe Recipe Down to a Science—Literally
Cooking the famous, creamy pasta sauce is as delicious as it is frustrating, because the cheese tends to clump when exposed to heat. That’s why Italian scientists created a new technique that’s “simple yet precise”
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The best Italian pasta sauces are often the simplest, with cacio e pepe (pecorino cheese and black pepper) being one of the most familiar—and, arguably, one of the most delicious. But simple shouldn’t be confused with easy. The recipe traditionally calls for mixing in a little bit of pasta water to make the sauce creamy—a deceivingly complex maneuver, since the pecorino often forms clumps because of the water’s heat.
From now on, however, all you frustrated cooks out there can rest easy, because a team of expat Italian researchers has gotten the recipe down to a science—literally. The foolproof ingredient? Extra starch.
“A true Italian grandmother or a skilled home chef from Rome would never need a scientific recipe for cacio e pepe, relying instead on instinct and years of experience,” the researchers write in a study detailing their work, published Tuesday in the journal Physics of Fluids. “For everyone else, this guide offers a practical way to master the dish.”
Starch enables cheese and water—two ingredients that would otherwise not mix—to blend together, keeping the sauce creamy, smooth and free of clumps. The water’s high temperature, however, changes the cheese’s proteins in a way that makes them stick to each other.
In sufficient quantities, “the starch [also] mitigates this effect by binding to the cheese proteins, reducing their direct interactions and, consequently, their aggregation,” explains Daniel Busiello, a co-author of the study and a researcher at the Max Planck Institute for the Physics of Complex Systems, to BBC Science Focus’ Hatty Willmoth.
For the naturally released starch in the pasta water to be sufficient, the researchers suggest letting the water cool before mixing in the cheese, then slowly heating the sauce up again. But they offer a shortcut for those looking for a quicker recipe.
“At higher starch concentrations, temperature becomes less of a concern, as the sauce remains smooth even with less precise heat control,” Busiello tells the Guardian’s Nicola Davis. “Our recommended scientific approach uses a starch-to-cheese ratio between 2 percent and 3 percent by weight, allowing home cooks to reliably create a smooth sauce without worrying too much about temperature.”
To prepare a cacio e pepe meal for two people—with around 11 ounces of pasta and 7 ounces of cheese—the team’s “scientific recipe” calls for 0.18 ounces of starch. It’s important to note that the starch should be added to water that’s separate from the pasta water. The researchers suggest measuring precise amounts of powdered starch such as potato or corn starch, according to a statement.
As such, 0.18 ounces of starch should be mixed into 1.8 ounces of water and heated until the mixture thickens into a gel. The researchers then recommend adding another 3.5 ounces of water into the starch gel to cool the mixture before blending in the cheese. Finally, add the black pepper.
In the meantime, you should have cooked the pasta in different, salted water (until it’s al dente, of course). After draining it, let the pasta sit for up to a minute to cool down before mixing it with the sauce. According to the paper, this approach “offers a simple yet precise way to consistently achieve a perfect cacio e pepe.”
While this method might cause some old-style Italian chefs to raise some eyebrows, Nathan Myhrvold, who was not involved in the research and co-wrote the famous cookbook Modernist Cuisine, told the New York Times’ Alexander Nazaryan that “what these guys did was a very impressive amount of work,” when the paper had been published as a preprint in January. However, he adds that starch can impact the flavor of cheese, and thus, adding the anticoagulant sodium citrate might provide a better option.
Nevertheless, “we tested our method with more than two kilograms of pasta,” Busiello tells BBC Science Focus, “and all the guests enjoyed it!”
