Juicy and sweet, small, round, and, well, blue, blueberries are a hallmark of summer, finding their way into pies, cobblers, muffins, poundcake, and pancakes. Blueberries are rich in pectin; with a bit of gentle cooking, they'll thicken into a delicious compote to drizzle over ice cream. Wild blueberries are smaller in size, with a deeper, more intense flavor. They're hard to find fresh outside of New England, but they're widely available frozen.
1 pint fresh = about 2 cups
You can judge some fruit with your nose, but not blueberries. Use your eyes first: Blueberries should have a lovely silvery-white bloom over the dark blue. Look for pints free of small, purplish or greenish immature berries, a sign that they were picked before their peak. Then use the heft test: Berries should be plump and heavy. The sure-fire way of judging blueberries is to taste a few, because sweetness is variable even within the same pint. Wild blueberries—much harder to find outside of the Northeast—should be tiny and almost black.
Pick the berries over and discard any immature berries or berries past their prime. Remove any stems and rinse the berries briefly in a colander. For most recipes, frozen blueberries should not be thawed before adding to a batter. Mix blueberries into batters gently and quickly, using as few strokes as possible to avoid crushing the fruit and turning the batter a glaring lavender.
Before storing your berries, pick through them, discarding any squishy berries that may turn moldy and infect their healthy neighbors. Store the berries in the coldest part of the refrigerator, but not in a drawer, where it's too humid and don't wash them until you're ready to use them. Fresh picked, they can last up to two weeks in an airtight container, although they can lose moisture during the second week and shrink slightly. For baking, this can work in your favor, however, because the flavor becomes concentrated. To freeze blueberries, rinse them in a colander, dry thoroughly on paper towels, and then spread them on rimmed baking sheets in a single layer until frozen solid. Once frozen, they go into plastic storage bags.