To make 3 cups of juice, select 12-15 very ripe pomegranates. Roll them while pressing firmly, one at a time, on the kitchen counter to soften the pulp and release juice into the fruit's interior. Next, hold each pomegranate over a bowl, puncture it with a small, sharp knife, and squeeze to extract all the juice. Strain, reserving any seeds for another use. The juice can be frozen in a plastic container for later.