2,887. What's Prohibited to a Nazir

Hilchos Nezirus 5:1

Three things are prohibited to a nazirite: being rendered ritually unclean from a corpse, shaving and ingesting grape products – both the fruit its the waste. Intoxicating drinks made from dates, figs, etc. are permitted to a nazir. The “beer” prohibited by the Torah is made from a wine mixture.

Hilchos Nezirus 5:2

“That which comes from the vine” means that a nazir is liable to the penalty of lashes if he eats an olive-sized portion of fruit – including fresh grapes, raisins or unripe grapes – or an olive-sized portion of waste, meaning the peels or seeds, etc. The same is true if he drinks a reviis of wine or ate an olive-sized portion of wine concentrate – which is considered fruit – or if he drinks a reviis of vinegar, which is like the waste. Grape leaves, the shoots of the vines, grape sap and the buds are permitted to a nazir because they’re neither the fruit nor its waste. Rather, they’re considered parts of the tree.