permitted a man, for his own use, to turn whatever wine he has into vinegar, however it came into his possession, and to consume it. Nevertheless, the preferable course is not to do so, but to hasten to pour it away, as the Companions—may Allah be pleased with them—did in the hadith narrated by Anas. Thus, there are three views on the permissibility of turning wine into vinegar: first, that it is impermissible in all cases; second, that it is permissible in all cases, though disliked; and third, that a distinction is made between deliberately keeping wine and having juice turn into wine without intending to produce it.
As for the permissibility of consuming it once it has been turned into vinegar, according to those who do not permit this process under any circumstances, there are three views: permission, prohibition, and a distinction between turning deliberately kept wine into vinegar and doing so with wine that formed without any intention to produce it. This last view is Sahnūn’s, while the first two are attributed to Mālik.
One of the Baghdadi scholars, namely ʿAbd al-Wahhāb, explained the prohibition on consuming wine deliberately turned into vinegar, according to al-Shāfiʿī’s school, on the grounds that it remains impure. This explanation is unsound: if it remained impure when deliberately turned into vinegar, it would have even more reason to remain so when it turned into vinegar on its own. Unless, by saying that it remains impure, he means that it retains the legal ruling of impurity concerning the prohibition on consuming it, even though its impurity has disappeared. This would have a valid basis: he would be treating the removal of the qualities of wine through deliberately turning it into vinegar like the removal of impurity from a garment by washing it with a liquid other than water. Wine deliberately turned into vinegar would then be pure, such that if any of it subsequently fell into water or onto a garment, it would not render either impure. Likewise, an impure garment washed with a liquid other than water until the impurity has disappeared would be pure, such that immersing it in pure water would not render the water impure. Yet the legal ruling of the wine’s impurity would remain attached to the vinegar, prohibiting its consumption, just as the legal ruling of a garment’s impurity remains attached to it after washing with a liquid other than water, prohibiting prayer in it. All this is clear, and all praise is due to Allah.
If someone asks, “If wine is impure, how does it become pure when it turns into vinegar on its own according to Mālik, when he holds that things rendered impure can only be cleansed of impurities with pure water?” the answer is that the distinction is as follows: impurities are substances that exist in their own right and are capable of persisting. When they mix with pure substances, they can only be removed from them, according to Mālik, with water, because Allah, Mighty and Majestic, says:
“And We send down from the sky purifying water” [al-Furqān: 48],
and tahūr (purifying)