Sunan an-Nasa'i #5723 · The Book of Drinks

Sunan an-Nasa'iIt was narrated that Sa'eed bin Al-Musayyab said
Sunan an-Nasa'i · Book 51 · The Book of Drinks
Sunan an-Nasa'i · كتاب 51 · كتاب الأشربة
"When At-Tila' (thickened grape juice) has been cooked and reduced to one-third, then there is nothing wrong with it
أَخْبَرَنَا أَحْمَدُ بْنُ خَالِدٍ، عَنْ مَعْنٍ، قَالَ حَدَّثَنَا مُعَاوِيَةُ بْنُ صَالِحٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، قَالَ إِذَا طُبِخَ الطِّلاَءُ عَلَى الثُّلُثِ فَلاَ بَأْسَ بِهِ ‏.‏
Reference : Sunan an-Nasa'i 5723In-book reference : Book 51, Hadith 185