Fresh basil can drastically enhance the flavor of so many dishes, making it a common staple in most kitchens. While it can be difficult to use all your fresh basil before it reaches its expiration date, knowing how to properly preserve your basil will allow you to enjoy it at your leisure. If you are interested in learning about different techniques for preserving fresh basil and other fresh basil products, read the tips outlined below.
Freezing Basil
Unfortunately, you cannot simply place your fresh basil in the freezer because the enzymes that decompose fresh plant material can survive freezing temperatures, and thus will drastically reduce the freshness of your basil.
Fortunately, blanching your basil before placing it in the freezer allows you to kill the decomposing enzymes. To blanch fresh basil, bring a large pot of water to boil and prepare another bowl of ice water. Once the water is boiling, dip your basil into it until it wilts (this should only take a few seconds). As soon as the basil has wilted, quickly transfer it into the ice water, which eliminates the residual heat that would otherwise continue cooking the basil. Pat the blanched basilĀ  dry, strip the leaves from the stems, transfer them into a freezer bag, and place it in the freezer.

Freezing Pesto or Herbal Oil in Freezer Bags

Pour or spoon your oil or pesto into freezer bags, you should pour in just enough to cover the surface of the bag when it is horizontal. Place the bag flat (horizontally) in your freezer so that you can easily break off and defrost the amount you want.

Freezing Pesto or Herbal Oil in Freezer Containers

Alternatively, fill ice cube trays with your basil oil or pesto and then place the trays in the freezer. After they are frozen, 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.