The fruits vary in shape, heart-shaped, spherical, oblong or irregular. The size ranges from 7 centimetres (2.8 in) to 12 centimetres (4.7 in), depending on the cultivar. When ripe, the fruit is brown or yellowish, with red highlights and a varying degree of reticulation, depending again on the variety. The flesh varies from juicy and very aromatic to hard with a repulsive taste. The flavor is sweet and pleasant, akin to the taste of 'traditional' custard.
The custard apple is native to the New World, but has been found on the island of Timor in Indonesia as early as 1000 C.E.
Custard apple may also be the name of some similar fruits produced by related trees? Ramphal Custard-apple - India