Answer: pasteurizes

AnswerCrossword Clue
PASTEURIZESPrevents fermentation.
pasteurizesPASTEURIZE, to treat milk so as to kill germs
pasteurizesSubject (milk, wine, or other products) to a process of partial sterilization, esp. one involving heat treatment or irradiation, thus making the product safe for consumption and improving its keeping quality