Sahih Muslim Book 23, Hadith Number 4960.
Chapter : Every intoxicant is Khamr and every Khamr is forbidden.
Abu Burda reported on the authority of his grandfather that Allah’s Messenger (may peace be upon him) sent him and Mu’adh b. Jabal to Yemen and said to them: Give good tidings to the (people) and make things easy (for them), teach (them), and do not repel (them); and I think he also said: Cooperate cheerfully with each other. When he (the Holy Prophet) turned his back, Abu Musa returned to him and said: Allah’s Messenger, they (the people of Yemen) have a drink which is (made) from honey and which is prepared by cooking it until it coagulates, and Mizr is prepared from barley, whereupon Allah’s Messenger (may peace be upon him) said: Every intoxicant that detains you from prayer is forbidden.