Although cooking pasta might be like second nature for most home cooks, there are actually quite a few ways to mess it up. Some of which are misnomers held as conventional wisdom in many households. And that begs the question of whether or not it's necessary to oil your pasta water.
For a lot of us, learning how to cook pasta is one of the first skills an amateur cook might add to their arsenal. I mean, it’s easy enough right? You salt some water, boil it, and then cook your noodles. What’s so tricky about that? As it turns out, there are plenty of little tricks and turns along the way that can determine the failure or success of your pasta-cooking experience. Whether it’s related to salting the pasta water or rinsing the pasta after it cooks, it’s important to make sure that you’re avoiding common, and often seemingly harmless, mistakes. Why? Because you deserve the best bowl of spaghetti possible.
Which brings us to our next dilemma of what is right and wrong in the world of cooking pasta, and that is whether you should or should not add olive oil to your pasta water. While it might seem like an innocent splash of oil couldn’t do any harm, your pasta is way better off without it. Generally, people will drizzle a bit of olive oil into their pasta water in order to prevent the noodles from sticking together... but that's not the only thing it's going to keep from sticking. What happens is that a layer of oil will form at the top of your pasta water, so when you drain your noodles from the water, the layer of oil will then coat all of your noodles as they’re drained. Admittedly, this is isn't a huge issue if you plan to dress your noodles in nothing but olive oil anyway, but for something like a Bolognese or simple marinara, its kind of an issue. This coating of oil will only cause your pasta to become slick and slippery—in turn, making it very difficult for any sauce to cling to the pasta. And what good does that do you? None!
Really, all you need to do is give your pasta noodles a stir every so often as they cook to prevent major clumping. If the noodles seem a little sticky one you drain them, that's A-OK (ideal, actually); they'll loosen up from one another once they have some sauce to cling to. So the moral of the story—save your olive oil for something else (like building a rich and robust sauce), because it surely does not belong in your pasta water.