Maaseros 1:1-2

Maasros 1:1

The Sages set a general rule regarding tithes: anything that is food for people, that is guarded by its owners, and that grows from the ground must be tithed. Also, whatever is food at the beginning and food at the end must be tithed even if the owner keeps them planted in order to increase his output, whether he harvests them when they’re big or small. Whatever is not food at the beginning and only becomes food at the end need not be tithed until it is actually food.

Maasros 1:2

Figs become liable to tithes after they have been gathered and left for 24 hours (at which point they are ready to eat). Grapes become liable to tithes as soon as the seeds can be seen through the skin. Mulberries and all red fruits become liable to tithes when they turn red. Pomegranates become liable when they get soft, dates when they expand like dough, peaches when the veins become visible, and nuts when the edible part separates from the shell. Rabbi Yehuda says that nuts and almonds become liable when the paper-like skin forms.