What is the ruling on using commercial vinegar labeled "alcohol vinegar" and homemade grape vinegar that spoils before turning into vinegar, and is expiation due from one who used it unknowingly of its prohibition?

The basic ruling for apple cider vinegar is permissibility, as long as it is not mixed with an intoxicant. If the vinegar contains alcohol or other intoxicants before their transformation and the intoxicating effect is removed, then it is forbidden. If wine transforms into vinegar by itself without intervention, it becomes pure and its use is permissible. However, if it is intentionally transformed into vinegar, it is not permissible and does not become pure according to the preponderant opinion. Based on this, vinegar that contains a percentage of alcohol is deemed impure unless it is proven that it transformed by itself. Its use in food and as an internal medicine for the body is forbidden. As for homemade vinegar, if it is not proven to have fermented to the point of becoming an intoxicant, then there is no harm in it, because the basic ruling for foods is permissibility unless it is known with certainty or strong probability that they contain harm, or that they have been mixed with an intoxicant or an impure substance.