Halacha forbids drinking wine belonging to a gentile and even wine belonging to a Jew that was touched by a gentile. There is, however, a famous exception to this rule, namely, that "Yayin Mebushal" – wine that has been cooked – does not become forbidden if it is handled by a non-Jew. Once the wine has been heated, it remains permissible even if a non-Jew touches it.
There is an important debate among the Halachic authorities regarding the level of heat required for wine to be considered "Mebushal." Whereas some authorities maintained that it suffices for the wine to be hot enough to cause one’s finger to recoil on contact, others, including the Shach (Rav Shabtai Ha’kohen, 1622-1663), required heating the wine until it boils and begins to evaporate.
This debate directly affects the status the status of wine or grape juice that has undergone the process of pasteurization, which conventionally is done by bringing the liquid to a temperature of 85 degrees Centigrade (approximately 170 degrees Fahrenheit), but not to the boiling point. (It should also be noted that as the vats are generally covered during pasteurization, no wine evaporates during the process.) According to the Shach, this process does not suffice to render the wine or grape juice "Mebushal," and this is, indeed, the ruling of several authorities, including Hacham Bension Abba Shaul (Israel, 1923-1998), in his Or Le’sion (vol. 2, chapter 20, note 18). This was also the view of Rav Shlomo Zalman Auerbach (Israel, 1910-1995). Rav Moshe Feinstein (Russia-New York, 1895-1986), however, in his Iggerot Moshe (Y.D. 1:50), accepted the lenient position, that pasteurization suffices to render wine or grape juice "Mebushal."
Hacham Ovadia Yosef, in his work Yabia Omer (vol. 8, Y.D. 15), ruled that one may rely on the lenient view of Rav Moshe Feinstein, but it is nevertheless preferable to treat pasteurized wine or grape juice as not "Mebushal" unless it was brought to a boil. If such wine or grape juice was touched by a gentile, one may drink it, but preferably one should not allow a gentile to come in contact with such wine, in deference to the stringent ruling.
In light of the Hacham’s ruling, one cannot necessarily rely on a wine company’s label that says that the wine is "Mebushal." Before allowing a non-Jew to handle the wine, one should determine whether the wine was brought to a boil, or merely pasteurized. If it was just pasteurized, then the wine is still kosher, but one should try not to allow a non-Jew to touch the wine. As mentioned, however, if a non-Jew did touch such wine, it is nevertheless kosher.
Summary: Wine that was touched by a non-Jew may not be drunk, unless it is "Mebushal" – meaning, it was heated. According to some opinions, wine is considered "Mebushal" only if it is brought to a boil, and thus pasteurization does not suffice. It is preferable to follow this view, and thus one should not allow a non-Jew to touch his wine until he has verified that the wine had been brought to a boil.
