In fact,higher temperatures and an increasing must sugar content,causes,in some years,an unacceptable alcohol content from the point of view of quality and health.even a technological point of view the new challenges are urgent,and a series of problems that were limited to certain types of wine fermentation,such as that of german eiswine or lialian passito,concerning the interaction between the yeast,usually saccharomyces cerevisiae,with a must particularly rich in sugar,have become relevant wven in fermentation of common wines.