Unlike some herbs that naturally thrive in cooler environments, basil doesn't do well in cold conditions, so keep it out of the fridge. Instead, store basil at room temperature.
When storing a bunch of fresh basil stems, treat the herb as you would a bouquet of flowers. If stemmed, the ends should be trimmed slightly then put in a glass jar with water.
To maximize freshness, loosely place a plastic bag over the basil. When left at room temperature and out of direct sunlight, basil should last for about a week or two.
If you're storing loose basil that has the stem removed, put it in a plastic bag and gently wrap it closed to avoid bruising, which can speed up discoloration and wilting.