Pesto from the freezer brings a reprise of summer’s fresh basil goodness during the colder months. The classic pureed sauce traditionally combines fresh basil leaves, olive oil, pine nuts, garlic and aged cheese, and sometimes butter. Pesto freezes well for serving in soups or as an element of a composed sauce.
Omit the butter when you are freezing pesto. You can also choose to omit the cheese as a matter of personal preference -- the pesto will freeze acceptably if you include it. Stir the butter into the thawed pesto later, and add fresh cheese if omitted to brighten the flavor.
The easiest way to freeze pesto this is to spoon it into an oiled ice-cube tray. Press the surface of each pesto cube with a spoon to create a hollow into which you can add a thin layer of olive oil to preserve flavor and color. Cover the tray with several layers of plastic wrap and freeze the cubes until they are solid. Avoid transferring the cubes to freezer bags for long-term storage, as they maintain their color better in the plastic-wrapped tray.
If you want to freeze a larger amount of pesto for sauce, ladle the pesto into a 1/2-cup or 1-cup freezer container. Cover it with a protective layer of olive oil, seal the container tightly and place it in the freezer.