Choose berries that are firm and indigo blue with a silvery frost. Do not wash until ready to use and store in a moisture-proof container in the refrigerator for up to five days.
To preserve blueberries, stem them if needed, rinse in a colander and freeze in airtight containers or bags. Many recipes call for two cups of berries, so measuring and freezing two-cup portions is convenient.
Thawed frozen berries can be pureed, strained and blended with honey or lemon juice to make a fruit sauce for desserts.