What is the ruling on using vinegar mixed with alcohol in cooking or salads, and what is the ruling on sweets that contain animal fats?

If vinegar is mixed with an intoxicating alcohol that causes inebriation, it is not permissible to consume it, as it involves using impure intoxicants. However, if the alcohol completely transforms and loses its intoxicating property before mixing, there is no harm in consuming the mixture, though it is preferable to avoid it and use natural vinegar.

As for animal fats (like ghee and butter), if they are derived from a live, permissible-to-eat animal, they are lawful. But if they come from an impermissible-to-eat animal or a dead animal, they are not permissible for consumption, as they are impure.

Scholars have differed regarding the milk and rennet of a dead animal. Sheikh al-Islam Ibn Taymiyyah inclined towards their purity, citing that the Companions ate the cheese of the Magians. Salman al-Farisi also stated that what is lawful is what Allah has made lawful in His Book, and what is unlawful is what Allah has made unlawful in His Book, and what He has remained silent about is that which He has pardoned.

As for animal fat taken from an animal, it is not permissible unless it is taken from a ritually slaughtered, permissible-to-eat animal. Otherwise, it is not permissible to consume it or add it to food.