A true Italian grandmother or a skilled home chef from Rome would never need a scientific recipe for Cacio and pepe, relying instead on instinct and years of experience. For everyone else, this guide offers a practical way to master the dish.
Phase behavior of Cacio and Pepe sauce [PDF], a scientific paper in which a team of pasta-loving physicists investigate the factors that contribute to successful (ie, non-separating) Cacio e Pepe sauce, and conclude by presenting a scientifically-optimized recipe to enable “consistently flawless execution of this classic dish.”
The concentration of starch plays a crucial role in keeping the sauce creamy and smooth, without clumps or separation. If the starch content is less than 1% of the cheese weight, the sauce is prone to separating into unpleasant system-sized clumps corresponding to the “mozzarella phase” in Figures 1 and 2. On the other hand, exceeding 4% starch results in a sauce that becomes stiff and unappetizing as it cools. […] The pasta water alone does not contain enough starch to stabilize the sauce effectively. As we already discussed, one could use pasta water “risottata”, i.e. boiled down to concentrate the starch, but the process offers little control over the final starch amount. A more precise and reliable method is to dissolve 4 grams of powdered starch (such as potato or corn starch) in 40 grams of water. …
