When most people make pasta, they believe they should add two things to the water. First is salt, which helps season the pasta (but doesn’t make the water boil any faster, to debunk another pasta myth). The second is oil, supposedly to keep the pasta from sticking together as it boils.
Why You Should Never, Ever Add Oil to Your Pasta Water
Most veteran pasta makers add oil to their pasta water to prevent the noodles from sticking together, or to keep the water from boiling over. But their best intentions could backfire, Curiosity reports.
Here’s why: Thanks to the basic rules of science, oil doesn’t mix with the water. As a result, only a tiny bit of the oil, if any at all, will even make it onto the pasta as the water boils. It’s more likely that the oil can attach to the noodles after you drain them, instead, preventing sauce from sticking to the pasta.
Pasta sticks when the starch molecules within it absorb so much hot water that they burst. That makes a bunch of starch rush out and coat the outside of the pasta piecesfor a few minutes at the beginning of the cooking process. Eventually, though, it dissolves and washes away, leaving the pasta smooth again.
Fortunately, there’s an easy fix to this cooking conundrum. Experts recommend using a large pot and lots of water to give the pasta plenty of room to move around as it cooks. You can also stir the pasta as soon as you place it in the pot—and periodically for the rest of the cooking time—to prevent the noodles from sticking together. And to avoid sticky pasta after it is cooked, try adding the sauce while both are still hot, or using a bit of water to loosen the noodles before serving. Who knew such a simple dish could be so complex?