Cheese clumping in pasta sauces like cacio e pepe is a common frustration, but experts have shared their secrets to achieving a smooth, creamy result. The key issue, according to Italian correspondent Rachel Roddy, is that cheese becomes too hot, causing the solids to lose fat and liquid and form blobs. The critical temperature difference between melted and coagulated is only a few degrees.
Tim Siadatan, co-owner of Trullo and Padella, recommends using hard, dry cheeses like parmesan, which are high in protein and less prone to melting. He advises grating the cheese finely and keeping it cool to prevent it from sweating and clumping beforehand. To control heat, some Roman chefs add grated ice to the pan, but Roddy prefers mixing cold water with cheese and pepper to a toothpaste consistency, then combining with hot pasta for a reliable emulsion.
Siadatan suggests adding cheese gradually over medium-low heat, a handful at a time, stirring constantly. He emphasises the need for liquid—such as water, butter, egg yolks, or cream—to create a velvety sauce. Mateo Zielonka, author of Pasta Pronto, grates cheese into a butter emulsion on low heat, or removes the pan from the heat entirely for dishes like fettuccine alfredo to avoid stringiness.
If clumping occurs, Roddy says it can sometimes be rescued by adding more cheese, cold water, and vigorous stirring. However, she also encourages embracing the mistake as a learning experience: seeing what happens when cheese is too hot helps perfect the technique.
