There is a well-known and very relevant halachic principle, that wine which has been cooked, known as yayin mevushal, is not subject to the prohibition of stam yenam, and is not prohibited by the touch of a non-Jew. The gemara (Avoda Zara 30a) relates the following story.
Shmuel and Ablet (a gentile scholar) were sitting together, and others brought cooked wine before them. Ablet withdrew his hand to avoid rendering the wine prohibited to Shmuel. Seeing this, Shmuel told Ablet that the Sages said: Cooked wine is not subject to the prohibition of stam yenam (and therefore you need not withdraw your hand on my account).
The Shulhan Aruch (Yoreh De’ah 123:3) rules in accordance with this gemara.
Why should cooked wine be any different not be subject to this prohibition? The Rosh (2:13) explains that in the past, wine was generally not cooked, and therefore it is considered to be "milta delo shachiah," an uncommon scenario. The rabbis only made decrees for cases which are common, not for cases which are considered to be unusual.
Some Aharonim, including R. Shlomo Zalman Auerbach (Minhat Shlomo 1:25), and R. Yosef Shalom Elyashiv (Netivot Hakshrut, Ellul 5752 pg. 13), question whether this leniency is still applicable, as cooked wine is very common today. R. Ovadia Yosef (Yabia Omer, Yoreh Deah 8:15), however, explains, that since at the time of the prohibition cooked wine was not prevalent, it is not included in the prohibition.
What is considered to be "cooked"? Maran (Shulhan Aruch, Yoreh Deah 123:3) writes that it is considered to be cooked from when it is "heated over the fire." The Shach (7), however, adds that the fire causes some of the wine to evaporate (nitma’et mimidato). The Vilna Gaon (7) cites a passage from the Talmud (Shabbt 40b) which implies that "heated" refers to the temperature of "yad soledet bo," the temperature at which a person’s hand recoils due to the heat of the liquid. This temperature is much lower than a liquid’s boiling point (212 degrees Fahrenheit).
Based upon this reasoning, R. Ovadia Yosef explains that if the wine reaches the temperature of yad soledet bo, which he understands as 176 degrees Fahrenheit, the wine is considered to be mevushal. Since all cooked wines are pasteurized, which is performed at an even higher temperature, pasteurization renders wine to be mevushal.
It is worth noting that Hacham Ben Zion (Or Lezion volume 2:20 [he’arot]) rules that since pasteurization occurs in pipes, and there is no evaporation, according to the Shach, this would not be considered to be mevushal. R. Ovadia Yosef disagrees and insists that the Shach relates to the temperature, and not to whether the wine actually evaporates.
In practice, it is customary to view pasteurized wine as mevushal, although R. Ovadia Yosef still writes that one who is strict and does not view pasteurized wine as mevushal is praiseworthy.