Fresh basil is one of the tastiest and most useful herbs, but it doesn't keep its color and flavor well when dried. Fortunately, there are other, better ways to preserve it, including freezing.
However, if you stick a bunch of fresh basil into the freezer, it will be discolored and mushy when it thaws. This is because the enzymes that decompose fresh plant material can survive freezing temperatures and work on the food even while it is in the freezer. The solution is to blanch the basil before freezing as blanching kills off those decomposing enzymes.
To blanch fresh basil:
- Bring a large pot of water to a boil. Have a big bowl of ice water ready.
- Once the water is boiling, dip your bunch of basil into it just until the basil wilts. This shouldn't take more than a few seconds. You don't want to cook out the flavor of the basil, just kill off those decomposing enzymes.
- As soon as the basil has wilted, immediately transfer it to the ice water. This eliminates the residual heat that would otherwise continue cooking the basil.
Freezing Blanched Basil Leaves
Pat the blanched basil dry. Strip the leaves from the stems and transfer to freezer bags and freeze. Tip: spread the leaves thinly in the bags and store flat. This will enable you to break off just what you need when you want to use some—but not all—of a bag of frozen herbs.
Watch Now: The Best Ways to Preserve Basil
Freezing Basil Oil or Pesto
After you've blanched, chilled, and patted your basil dry, strip the leaves from the stems. Put them in a blender or food processor and puree, adding enough extra-virgin olive oil to make a smooth, somewhat liquid paste. Or simply use the blanched leaves to make your favorite pesto recipe before freezing.
Pour or spoon your basil oil or pesto into freezer bags. Put in just enough to cover the surface of the bag when it is flat on the counter. Place in the freezer this way (horizontal). What you'll end up with is a pesto "pancake" from which you can break off just what you need.
If you'd rather have pre-measured portions, use small containers—or better yet, an ice cube tray. Add the oil or pesto, cover, and freeze, then pop out the cubes and transfer them to freezer containers (or freezer bags). Each cube will be approximately 1 tablespoon of basil oil or pesto.