What is the ruling on the juice of grapes if it is boiled by itself or by heat?

Religious Authority: 
Ali al-Sistanti
Fatwa Question or Essay Title: 
What is the ruling on the juice of grapes if it is boiled by itself or by heat?

The juice of grapes is forbidden if it boils by itself or by fire or by the sun. If it does not become alcohol, its prohibition is gone. If it becomes alcohol, its prohibition can only be removed after it becomes vinegar. If grapes cook themselves and if it is known that their contents have been boiled, drinking the liquid is absolutely forbidden; otherwise it is not forbidden, just as what is called "grape juice" is not forbidden, even if it has been boiled, unless it becomes an intoxicant. Then it becomes forbidden until it turns to vinegar.

ما حکم عصیر الزبیب اذا غلی بنفسه او بالنار؟ يحرم عصير الزبيب اذا غلى بنفسه أو بالنار أو بالشمس فان لم يصر بذلك مسكراً تزول حرمته بذهاب ثلثيه ، وأما إذا صار مسكراً فلا تزول حرمته الا بالتخليل. واذا طبخ العنب نفسه فان حصل العلم بغليان ما في جوفه من الماء حرم على الأحوط والا لم يحرم ، كما لا يحرم ما يسمى بالعصير الزبيبي وان غلى الا ان يصير مسكراً فيحرم عندئذٍ ولا تزول حرمته الا بالتخليل.