Like all food and drink, for something to be kosher it has to be made of only kosher ingredients. Wine, made from grapes, might seem an unlikely candidate for concern about kosher ingredients, but thanks to a history of use in pagan ritual, wine has its own set of rules.

Meaning

Mevushal means “boiled,” and once wine has this status it cannot be used for idolatrous purposes. This is important because wine that has been used for idolatry cannot be considered kosher and used for Jewish ritual practices.