Blueberries Measurements and Conversions

Sort the berries first, picking out stems, leaves and any that are soft or split. Pour the rest into a dry measuring cup, tap it once on the counter so they settle into place, and level the top with your hand. Pressing blueberries down bursts the skins and turns part of the cup into juice.

A cup of round fruit is partly air, because the berries touch each other at only a few points. That is why a well-settled cup weighs a little more than one filled loosely, and why USDA's number is a guide for your cup rather than an exact weight.

Wash blueberries only if you can dry them well, since wet fruit carries extra water into the cup and then into the batter. Frozen berries stick together in clumps: break them apart and measure them frozen solid, because thawed berries soften and take up less room.

For muffins, pancakes and salads, a cup measure is plenty accurate. Jam is the exception, since its set depends on the balance of fruit and sugar, so weigh the fruit for it.

Clamshells labeled by weight convert to cups with USDA's figure for whole raw blueberries:

• 6 oz fills about 1.1 cups.
• 11 oz fills about 2.1 cups.
• 18 oz fills about 3.4 cups.
• 2 lb fills about 6.1 cups.

A 125 g punnet, as the small box is called in the UK, holds about 0.8 of a US cup.

The pint used on this site is the US liquid pint of 2 cups. NIST Handbook 44 also defines a US dry pint for dry goods, about 16 percent larger. A basket sold as a dry pint therefore holds roughly a third of a cup more fruit than a liquid pint.