Sahih Muslim Book 23, Hadith Number 4941.

Chapter : It is forbidden to prepare Nabidh is varnished jar, gourd, green pitcher, and hollow stumps.

Muharib b. Dithar reported: I heard Ibn ‘Umar say: Allah’s Messenger (may peace be upon him) forbade (the preparation of Nabidh) in a pitcher besmeared with pitch, in gourd, in varnished jar. He said, I heard it from him more than once.