When fruit does not jelly it is usually because it is over ripe.
Grapes must be fresh and not over ripe or they will not "jell" nicely.
Ripe fruit may be eaten during hot weather with great benefit, only it must be ripe and not over ripe.
In carrying the bananas on shore the over ripe ones would drop off.
Thus it came about that the harvest was ripe, and over ripe, awaiting ...