Bowl of fresh pasta al pesto topped with parmesan and toasted pine nuts Pesto alla Genovese is deceptively simple — basil, pine nuts, garlic, parmesan, olive oil — and yet most home versions come out dull green, bitter, or oily instead of the bright, glossy sauce you get in Liguria. The difference isn't the ingredients. It's the order and the temperature. Why Homemade Pesto Usually Goes Wrong The two most common mistakes: blending the basil too long (it bruises and turns bitt