سنن النسائي

It was narrated from Ibn Al-Dailami that his father said: "We said: 'O Messenger of Allah, we have grapevines; what should we do with them?' He said: 'Make raisins.' We said: 'What should we do with the raisins?' He said: 'Soak them in the morning and drink them in the evening, and soak them in the evening and drink them in the morning.' I said: 'Can we leave it until it gets stronger?' He said: 'Do not put it in clay vessels, rather put it in skins, for if it stays there for a long time, it will turn into vinegar.'"