Drinks (Kitab Al-Ashribah)
Dawud :: Book 26 : Hadith 3686
Narrated Qays ibn an-Nu'man:
The Prophet (peace_be_upon_him) said: Do not drink from hollowed stumps, vessel smeared with pitch, pumpkins, and green jars, but drink from a skin which is tied with string. If the drink ferments, lighten it by infusing water. If you are helpless, then pour it away.