How is vinegar made according to Islamic law?

It is not permissible to transform wine into vinegar, due to the prohibition of the Prophet, peace and blessings be upon him, regarding it, and because wine is commanded to be poured out. It is not permissible to use vinegar if the wine was transformed into vinegar by an agent, according to the preponderant opinion. However, if the wine transformed into vinegar by itself without intervention, then the use of its vinegar is permissible.