Spots are always hard and never turn into a soft rot. Primary leaf and fruit infection occurs very early in the season as soon as the first green tissue is present. The fungus responsible for bitter rot can infect the fruit anytime after petal fall. The disease is severest as fruit reaches maturity. Small, brown, circular areas develop anywhere on the fruit surface.
Spots later become sunken, forming a saucer-shaped depression.
Under wet weather conditions, pink fruiting bodies of the fungus develop in the center of the rotten area. Two types of rot occur on the fruit. One type appears to rot the fruit from the inside outward. The entire apple becomes soft but retains its shape and takes on a light brown color. When dropped, the rotten fruit falls completely apart.