Because I am severely allergic to pine nuts, I always make my own pesto using toasted pepitos, walnuts, almonds, or pecans. I have made it from Swiss Chard, Kale, etc. I usually freeze it in ice cube trays. I top the pesto with oil. I have kept it for 6-9 months. I avoid restaurants that serve pesto or any dish with pine nuts on the menu. It takes fewer than 3 pine nuts to throw me into anaphylaxis. If you have never experienced (and survived) anaphylaxis, once is enough.