Our Pesto is fresh and preservative free.  After purchase, it is recommended to be refrigerated within a reasonable amount of time to retain quality.  If you feel you can not consume within several weeks, we advise to freeze.  Pesto can last months frozen. As with any grocery item - "Fresh is Best" for color vibrancy and taste. Once opened, if the product is not fully used, it helps to add a layer of oil  (to seal, keep moist, and last longer)