Al-Kāfi - Volume 6 > Al-Tila’ (The One-Third Juice (grape juice) that has Remained after the Evaporation of the other Two-Thirds)
Hadith #3

أَبُو عَلِيٍّ الْأَشْعَرِيُّ عَنْ مُحَمَّدِ بْنِ عَبْدِ الْجَبَّارِ عَنْ مَنْصُورِ بْنِ حَازِمٍ عَنِ ابْنِ أَبِي يَعْفُورٍ عَنْ أَبِي عَبْدِ اللَّهِ ( عليه السلام ) قَالَ إِذَا زَادَ الطِّلَاءُ عَلَى الثُّلُثِ فَهُوَ حَرَامٌ .

3. Abu Ali al-Ash‘ariy has narrated from Muhammad ibn ‘Abd al-Jabbar from Mansur ibn Hazim from ibn abu Ya‘fur who has said the following: “Abu ‘Abd Allah, ‘Alayhi al-Salam, has said, ‘If al-Tila ’ (the remaining boiled juice) is more than one-third it is unlawful for use.’”