Sunan an-Nasai Book 51, Hadith 5746

أَخْبَرَنَا سُوَيْدٌ، قَالَ أَنْبَأَنَا عَبْدُ اللَّهِ، عَنْ شُعْبَةَ، عَنْ قَتَادَةَ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، قَالَ إِنَّمَا سُمِّيَتِ الْخَمْرُ لأَنَّهَا تُرِكَتْ حَتَّى مَضَى صَفْوُهَا وَبَقِيَ كَدَرُهَا ‏.‏ وَكَانَ يَكْرَهُ كُلَّ شَىْءٍ يُنْبَذُ عَلَى عَكَرٍ ‏.‏

It was narrated that Sa'eed bin Al-Musayyab said:"Khamr is so called because it is left until the good parts are gone and the dregs remain." And he disliked everything that was made by using dregs (by adding new materials to the dregs)