Spaghetti is one of those things you learn how to make when you’re young . . . because it’s quick, easy, and you can eat leftovers for a week. But unless you know this simple trick, you’ve probably been doing it WRONG your whole life.
Instead of just straining the pasta when it’s done, you should be SAVING some of that water, and adding it to the sauce.
Here’s why . . .
You’ve probably noticed the pasta water gets really cloudy. But that doesn’t mean it’s “dirty” or bad. That cloudiness is just starch. And adding some of that starch to your sauce will THICKEN it because of something called emulsification.