Purity: Ruling on Reduction and Bubbling of Grape Juice Without Fermentation

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 197

If two-thirds of grape juice reduces without bubbling, in the event that the remainder bubbles and is commonly called ‘grape juice’ and not ‘grape syrup’, then based on obligatory precaution, it is unlawful to drink.

-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)