Which type of vinegar did the Prophet, peace and blessings be upon him, mean in his saying: "The best of condiments or the best of foods is vinegar"?

The text of the Hadith is: "Vinegar is an excellent condiment," narrated by Muslim. What is meant by it is vinegar that was not made from wine. The preponderant opinion among scholars is the prohibition of purposefully fermenting wine into vinegar, and that it does not become pure if it is purposefully fermented. However, if it transforms into vinegar on its own, the preponderant opinion is that it is pure.