Abu Dawud Book 20, Hadith Number 3701.
Chapter : Drink made from raisins or dates nabidh.
Narated By Ad-Daylami : We came to the Prophet (PBUH) and said to him: Apostle of Allah, you know who we are, from where we are and to whom we have come. He said: To Allah and His Apostle. We said: Apostle of Allah, we have grapes; what should we do with them? He said: Make them raisins. We then asked: What should we do with raisins? He replied: Steep them in the morning and drink in the evening, and steep them in the evening and drink in the morning. Steep them in skin vessels and do not steep them in earthen jar, for it is delayed in pressing, it becomes vinegar.