The Gold Standard for Pesto

If you plan to use the pesto within the next 7-10 days, the refrigerator (fridge) is sufficient, but the number one enemy is oxygen.

Glass jar: Transfer the pesto to a small glass jar (filling it as much as possible). Oil layer: Smooth the surface with a spoon and pour a thin layer of olive oil over the top until it is completely covered. This creates a physical barrier that prevents the air from oxidizing the basil. Maintenance: Each time a spoonful is removed, smooth the surface again and add a splash of extra oil to "close" the seal.