If kosher wine was mixed with forbidden wine, what is the status of the mixture?
The Halacha in this case depends on which kind of forbidden wine was mixed with the kosher wine. If the wine was "Yayin Nesech," meaning, wine that had actually been used in a pagan ritual service, then the entire mixture is forbidden and must be discarded. Even if only a minuscule amount of "Yayin Nesech" mixed with the kosher wine, the wine is forbidden, and one may not drink or derive any form of benefit whatsoever from the wine.
If, however, the wine was not used for a religious ritual, but was forbidden because it belonged to or was touched by a gentile, then the Halacha will depend on whether the non-Jew who owns or touched the wine is considered an idolater. Moslems believe in and worship a single Creator, and thus are not considered idolaters. Therefore, the status of wine owned or touched by a Moslem is less strict than that of wine owned or touched by other non-Jews. If wine owned or touched by a Moslem mixes with kosher wine, then we may apply the rule of "Bittul Be’shishim," which means that the wine is permissible if the forbidden wine constitutes 1/60th or less of the mixture. So long as the proportion of kosher wine to forbidden wine is at least 60:1, the wine is permissible for drinking and all other forms of benefit.
If the forbidden wine that mixed with the kosher wine was owned or touched by other non-Jews, who are considered idolaters, then the wine may not be drunk regardless of the proportion of the kosher wine. Even if only a small amount of forbidden wine mixed with the kosher wine, the wine is forbidden for drinking. One may, however, sell the mixture to a non-Jew, and then destroy the amount of money equal to the value of the forbidden wine in the mixture. For example, if the forbidden wine constituted 1/15th of the mixture, and the Jew received $15 for the wine, he must destroy $1 by burning it, throwing it into the ocean, or the like, so that no one derives benefit from the forbidden wine. The rest of the money, however, is permissible and may be used.
(Based on Ben Ish Hai, Parashat Balak, 12)
Summary: If even a small amount of non-Jewish wine mixed with kosher wine, the entire mixture is forbidden for drinking. One may, however, sell the mixture, and then destroy the portion of the money received that is equal to the value of the forbidden wine in the mixture. There are, however, two exceptions to this rule. If the non-Jewish wine in the mixture was forbidden because it was owned or touched by a Moslem, then the mixture is permissible for drinking, assuming the forbidden wine constitutes 1/60th or less of the mixture. Secondly, if the forbidden wine had been used in pagan worship, then the entire mixture is forbidden for any purpose, regardless of the proportion of kosher wine against the non-kosher wine.
