Basil should be boiled very briefly before it is frozen so that it retains its green color once it is thawed. Basil can be placed in a bag or blended with other ingredients before freezing.
Basil leaves should be dipped in a pot of boiling water for 30 seconds, then drained. Rolling the drained basil in a clean kitchen towel helps to remove any excess moisture. The basil should then be portioned and placed into plastic bags. Portioning is important, as basil cannot be refrozen once it has thawed. Air should be pushed out of the bags before they are placed in the freezer.
Alternatively, a basil and olive oil puree can be frozen in ice cube trays and added to soups and sauces as necessary.