How to Freeze Fresh Basil - 1. Carefully pull basil leaves off of stem one-by-one, and place in a colander. 2. Rinse the leaves thoroughly under cool water. 3. Spread out enough paper towels to dry basil leaves on. 4. Place all of the washed basil leaves on the paper towels and allow them to completely dry. 5. Carefully fill freezer bag with basil leaves and tightly close bag. Store basil in freezer and use whenever you need some basil.