Turns Out, There’s a Reason Why You Can Add Olive Oil to Pasta Water

The Internet is full of articles and videos that recommend adding oil to the pasta cooking water to prevent it from sticking. It's one of those false myths passed down by grandmothers, according to which slippery oil would prevent the pasta from sticking. It's all false: adding oil to the water to prevent the pasta from sticking is useless. Oil and water have different densities, the former floats and therefore cannot "divide" the pasta. The advice is always to use plenty of water and a large pot so as to "dilute" the starch but we will surprise you: adding oil to the cooking water actually has a very specific "benefit".

The Oil is Used to Prevent the Foam From Forming

Oil prevents foam from forming, that annoying phenomenon that causes water to overflow the pot when you cook pasta with the lid on. Foam forms because the starch in the pasta creates a "plug" on the surface of the liquid that prevents all the steam from escaping. This builds up and so at a certain point the starch "plug" rises until the water comes out.

Why does oil prevent water from foaming? We asked Alberto Colella, a famous food blogger and esteemed chemist: "Most oils act as anti-foams, even in the laboratory we use them". Antifoam is a silicone-based compound used to reduce foam in water-based systems.

In practice we must imagine the oil divided into two "souls": one loves substances similar to water, the other hates them . "In the graphics – continues Colella – we can see the orange head that loves water and the tail that hates it. Like dissolves like: the heads join together to make the foam because there is an affinity with the air-liquid surface, the tails join together and the foamy structure disappears". The chemist also gives us another example linked to the home world: "The same concept can be applied to the chemical agents in detergents: they bind to dirt and remove stains in the same way as oil in water that prevents foam".

Adding oil to the water during cooking is therefore useless for everything except the foam. To avoid this inconvenience, a few small precautions are actually enough: always use plenty of salted water (1 liter for every 100 grams of pasta) and stir frequently during cooking. If you do these two things, you can also avoid adding oil.