Pesto Pasta

Why This Pesto Pasta Works

As the spaghetti boils in salted water, the strands soak up the seasoned water and swell. By the time it is drained, the pasta is soft but still has a little bite, and its surface is a bit rough, which lets the pesto cling instead of sliding off.

Inside the food processor, the basil, parmesan, pine nuts, and garlic are chopped into tiny pieces. As the blades spin and the olive oil is poured in, the oil slips into all those little gaps. The cheese and nuts thicken the oil so it doesn’t just run off the pasta later. It turns into a loose, green paste that can coat every noodle.

Once the warm pasta is tossed with the pesto, the heat from the spaghetti loosens the olive oil even more, so the sauce spreads and covers everything. The cherry tomatoes go in at the end, staying fresh and a little firm. Their juice mixes with the oily pesto on the pasta, so each bite has a smooth, slick coating instead of a dry or clumpy one.

Mistakes To Avoid

Letting the pasta sit too long after draining makes it clump and dry on the surface. Once it cools and sticks together, the pesto can’t slide between the strands, so some bites end up coated in thick paste while the middle of the clumps stays almost plain.

Adding hot pasta straight from the pot into a tiny amount of pesto can cause the cheese in the sauce to seize into little lumps. Instead of a smooth coating, the pesto turns grainy and patchy, and the oil separates and pools at the bottom of the bowl.

Running the food processor too long after the oil goes in can overwork the basil and nuts. The mixture warms up, the basil darkens, and the pesto turns heavy and almost pasty instead of loose and glossy.

Tossing the cherry tomatoes too hard or too early breaks them down. Their juice leaks out, thins the pesto, and the pasta ends up sitting in a watery green puddle with bits of tomato skin floating around.