“Wine vinegar is lawful whether it became vinegar naturally or was processed into vinegar due to his statement (peace and blessings of Allah be upon him), ‘The best of condiments is vinegar’ unrestrictedly.”
[Al-Ikhtiyar, Chapter of Drinks]
Wine vinegar is permitted unrestrictedly in the Hanafi School and according to the strongest opinion in the Maliki School. However, processed wine vinegar is not permitted in the Shafi’i and Hanbali Schools.
Answered by Shaykh Bilal Brown