This is my favorite way of preserving basil for the winter. Follow these simple instructions and you have a basil log you can pull out of the freezer all winter. Simply slice what you need from the end of the log and place it back in the freezer.
Originally inspired by awaytogarden.com
Harvest Basil and wash in colander.
Pick off leaflets and pat dry (or spin in salad spinner, or if your basil was clean to begin with, don’t wash it at all!)
Put a lot of clean dry leaves in a freezer bag. Then compress the leaves in a log shape at the bottom of the bag.
Gradually squeeze the air out of the bag as you go, really compressing the basil. The log should be firm. Secure with rubber bands.
Label and Freeze.