Look for evenly colored leaves without signs of wilting. Keep basil in the refrigerator, wrapped in a damp (not wet) paper towel, then in a plastic bag. It will last even longer if you store a bunch of basil in glass of water, stems down. Place a plastic bag over the leaves and refrigerate the entire thing, changing the water every couple of days.

If you have more basil than you can use, try freezing the leftovers. The color will darken, but the flavor is still superior to dry. You can also preserve fresh basil by layering cleaned leaves with coarse salt and storing in an airtight container. Another great way to use an abundance of basil is to make pesto, which can be frozen in small amounts and used to flavor meats, pastas, pizzas and any number of other dishes.