There is difference of opinion among Hanafi and Shafi Fiqh schools regarding the vinegar. Since there is possibility of wine being not 100% converted to acetic acid and water
Ingredients such as whie wine vinegar and cider vinegar are permissible. The first being an alcoholic fermentation (which is Haram/Prohibited) and the seconf an oxidation of alcohol by aceto bacter, when it’s molecular structure is changed and it ceises to be an intoxicant. In vinegar the intoxicating factor is destroyed by the microbial process of oxidation hence it becomes permissible. Thus according to Hanafi jurists the use is permissible.
There are 2 opinions within the Shafi School. According to some Shafi jurists there is possibility of wine being not 100%
converted and not loosing its intoxicating factor during the process, thus it is prohibited. However some Shafi jurists do allow the use of wine vinegar as an ingredient as it is impossible to consume vinegar itself and become intoxicated.
DHCI follows the Hanafi opinion, Maliki opinion ,Shafi opion of some Shafi jurists and the opinion of many contemporary
Islamic Jurists of today.
Prophet Muhammad (peace and blessings be upon Him) has said: ‘Vinegar is comfort for man’ (Muslim)
Another well-known Hadith (saying of the Prophet Muhammad,peace and blessings be upon Him), transmitten by Al-Bahaiqi is: ‘
A household which has vinegar in it will never suffer from poverty’.
A contemporary scholar today, Sheikh Yusuf Al-Qardawi, who is considered to be an authority in the Middle East has allowed the use of wine vinegar in his book: ‘The Lawful and Prohibited in Islam’.
Sheikh Yusuf Al-Qardawi futher states that in the books of Maliki Fiqh is is stated that it is permissible to treat wine so that it becomes vineger.
Sheikh-ul-Islam Dr. Tahir-ul-Qadri, an authority on Islamic Fiqh, also holds the opinion that the use of wine vinegar if permissible.
While contributing to an article on Istihala: Change of State, Sheikh Dr. Jaafar Al-Quaderi gave an example where he said “Wine is Haram as long as it remains wine. However, if the same wine is turned into vinegar, it becomes halal. Hence the use of vinegar derived from wine is halal.”
In conclusion, vinegar has been consumed by Muslims for centuries, even during the time of Prophet Muhammad (peace and blessing be upon Him). The product itself, as manufactured by the industry and commercially available, is Halal