Sahih
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 .
It was narrated that Sa'eed bin Al-Musayyab said:"When At-Tila' (thickened grape juice) has been cooked and reduced to one-third, then there is nothing wrong with it