Make sure to check the carton or package for rotten, shriveled, or moldy berries when purchasing fruits such as strawberries, blueberries, and blackberries. Damage is easier to spot with these fruits because they are so small. Remember that if you can see one bad fruit from the outside, there are probably more on the inside. Berries should be firm and uniform in color. Berry juice coming out of the box is also not a good sign.