QUESTION: I have seen bottles of grape juice that are labeled “Non-Mevushal”. How can that be? Isn’t all grape juice pasteurized?

ANSWER: While it is true that all grape juice is pasteurized, however to be considered “mevushal”, it is not enough just to be heated, but it must be cooked to the point that the wine is “nismayet” (lessened). There are differing opinions as to how hot this must be. To achieve pasteurization which will kill the yeast and keep the juice from fermenting, it is enough that the grape juice be heated to about 150oF. However, to accomplish “mevushal” Rav Moshe Feinstein zt”l (Igros Moshe YD 2:52 & EH 4:108) writes that it must be heated to 175oF. The OU requires that the juice be cooked even hotter than 175oF to ensure that the temperature of 175oF is met. Grape juice or wine that is labeled non-mevushal does not mean that it has not been cooked at all, it just means that it did not meet this higher temperature requirement.

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The Gerald & Karin Feldhamer OU Kosher Halacha Yomis is dedicated to the memory of Rav Yisroel Belsky, zt"l, who served as halachic consultant for OU Kosher for more than 28 years; many of the responses in Halacha Yomis are based on the rulings of Rabbi Belsky. Subscribe to the Halacha Yomis daily email here.