Look for Color Change: As the fruit ripens, its color changes from green to a light yellow-green or even brownish-green. A dark green color usually means it's under-ripe.
Softness: Gently press the fruit with your fingers. A ripe soursop will yield slightly under pressure, indicating it's soft and ready to eat.
Distinct Aroma: When ripe, soursop has a strong, sweet aroma. If it smells sour or off, it may be overripe.
Spines Loosen: The spines on the soursop’s skin will begin to soften and loosen when it's ripe. If they are still hard, the fruit is likely unripe.
Size: Ripe soursop tends to be larger, though size can vary by variety. Ensure it feels full and heavy for its size.
Avoid Overripe Fruit: A very dark, mushy fruit could be overly ripe, which may affect flavor and texture.
Check the Flesh: Inside, ripe soursop has white, fibrous flesh. It should not be too watery or dry.
Storage: Soursop ripens best at room temperature, so avoid refrigeration until it's fully ripe.