وَعَنْ أَنَسٍ
أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ سُئِلَ عَنِ الْخَمْرِ يُتَّخَذُ خَلًّا؟ فَقَالَ: «لَا»
Anas told that the Prophet (sallallahu alayhi wa sallam) was asked about wine which was turned into vinegar* and forbade it. Muslim transmitted it. * This is said to have been done by putting onions or salt in it, or by placing it in the sun.