I always start a few sweet basil plants in Spring, and plant them out in the tomato and pepper bed. I start picking leaves as soon as possible to use fresh all summer long. But basil is one of the first things nipped once the nighttime temps drop even close to freezing. When that time comes (2-3 weeks yet? maybe?), I'll cut what ever is left and hang to dry. In the meantime, the plants are lush and I just cut a big bunch to make another batch of pesto to freeze for later.
I swish the basil through a couple sinkfuls of cold water, pile it back into the wire harvest basket, take it outside and swing it vigorously 'round and 'round overhead (the country version of a salad spinner), then bring it back in and dump it into the dish drainer to dry completely. Pick just the completely dry leaves from the stems, until you have a 2-cup measure packed tightly full. My recipe is adapted from one published by Ellen Ecker Ogden in her book From the Cook's Garden, where I got the idea to add a bit of lemon juice to the traditional recipe.
Basil Pesto (makes two ½-pint jars)
4 garlic cloves
2 cups tightly packed basil leaves
¼ cup pine nuts
¼ cup lemon juice
½ cup extra virgin olive oil (plus extra for topping off jar)
¼ cup freshly grated Parmesan cheese
Starting with just the garlic, then adding the rest, blend everything together in a blender (you can use a food processor - I don't have one - or if you want to really do it the traditional way, use a mortar & pestle to pound everything together), stopping frequently to mash everything down until it churns continuously in an homogeneous paste. Divide between two ½-pint jars, leaving ½" expansion room, smooth the tops, add enough oil to completely cover the pesto, add lids (can reuse clean old ones), and freeze. If you have any left over, make yourself a pesto and tomato sandwich!
All winter long, I thaw out a jar as needed - stirring glops into soups or pasta dishes, spreading on sandwiches or pizza, topping veggies or chicken. Keep a thawed jar refrigerated, and just make sure to re-smooth the top and add more oil to cover as needed. Made now, it will bring a welcome taste of summer brightness to those dark winter nights.