If you've ever attempted making cacio e pepe at home and ended up with pasta coated in gritty cheese bits instead of a luscious sauce, know that you are not alone. Thats why I ran to the kitchen after reading that adding a smidge of corn starch (about of a teaspoon per serving) ensures a creamy, emulsified sauce every time. Im happy to report that this tip is completely legit. And it requires barely any extra work!Cacio e pepe, the much beloved, deceptively simple pasta dish featuring pecorino romano cheese and black pepper, is easy to makeon paper. Just stir grated cheese into some pasta and a bit of the starchy pasta water you used when boiling it, add some pepper, and behold your creamy, cheesy dinner. But this simple procedure can produce mixed resultssometimes youll have perfect sauce, and other times, you'll wind up with a tragic bowl of noodles and cheese clumps surfing in water. Heartbreaking. It turns out this inconsistency has bothered a number of hungry food scientists too, and theyve figured out that a bit of added cornstarch is the best foolproof hack to avoid it. So I decided to give it a whirl.What science tells us about cacio e pepeThe reason you can achieve a silky pasta sauce from nothing but aged cheese and pasta water is because of the starch that leaches into that very water. Unfortunately, this process is incredibly inconsistent, and will vary with your water to pasta ratio when boiling the noodlesand even then it's usually around 1% when 2% to 3% starch is needed to stabilize the sauce.They suggest making a small amount of cornstarch slurry, cooking it into a gel, and building your sauce with this starchy foundation to ensure you always have a consistent amount to make the sauce work. The cornstarch gel cooks into a translucent gel. Credit: Allie Chanthorn Reinmann Before running the test, I feared the sauce might end up too cornstarch-heavy, like a white gravy instead of a cheese sauce, but I was actually rather pleased with the results. The small amount of gel blends right into the other ingredients and cornstarch carries no flavor of its own, so its presence is completely undetectable. The finished sauce is smooth and tastes fiercely of pecorino, as it should. Most importantly, no cheese curds developed. The cornstarch boosted sauce is tighter and silkier. Credit: Allie Chanthorn Reinmann Cacio e pepe without the cornstarch gel can remain stubbornly watery, or worse, the cheese proteins curdle. Credit: Allie Chanthorn Reinmann The directions are a little vague in the Popular Science article above, and theres a step where they add the cheese and gelatinized starch to a blender. For me, the tiny amount of ingredients involved does not warrant a blender clean-up (thats more trouble than its worth), so heres what I did instead.Foolproof Cacio e Pepe RecipeIngredients: teaspoon cornstarch1 tablespoon water1 ounce Pecorino Romano cheese, finely grated2 ounces spaghettiCracked black pepper1. To make the starch booster, combine the cornstarch and water in a small bowl. Stir them together until completely combined and add it to a medium-sized pan. Heat the pan over medium-low heat and stir with a rubber spatula until it gels. This happens quickly, it only takes about a minute. Let it cool while you boil the pasta.2. Cook the pasta in boiling salty water according to the package directions.3. Add the grated cheese to the starch gel and mix them together a bit. Add the hot, freshly boiled pasta to the pan with a tablespoon or so of the cloudy pasta water and stir everything around over medium-low heat. The ingredients will combine to make a creamy sauce. Add more pasta water if you like a looser consistency. Garnish with plenty of black pepper and enjoy immediately.