How do physicists make the perfect cheesy pasta sauce?

Phase behavior of Cacio e Pepe sauce

A team of Italian physicists worked out how to make cacio e pepe pasta sauce without it going lumpy.

Bartolucci, G., Busiello, D. M., Ciarchi, M., Corticelli, A., Di Terlizzi, I., Olmeda, F., et al. · Physics of Fluids, 2025

Ig Nobel 2025

Cacio e pepe is just pasta, cheese, pepper and starchy water, yet the cheese loves to clump into stringy lumps. These physicists mapped exactly when and why that happens.

Too little starch or too much heat sends the sauce into what they cheerfully call the “Mozzarella Phase”. Their fix: dissolve a little extra starch in the water and mix gently, a recipe with error bars.

the verdict

The only phase diagram anyone has ever wanted to eat.