Patent ID: 8679777

Claim:
A method of selecting a yeast strain that is resistant to a toxic medium, comprising the steps of: fermenting at least one yeast strain in a toxic selective medium and in a non-toxic selective medium, wherein the initial composition of the toxic selective medium is the initial composition of the non-toxic selective medium with addition of at least one non-ionized organic acid at a concentration that has a toxic effect on alcohol production by the yeast strain deposited on Sep. 4, 2008 at the CNCM under number I-4071, and wherein sugar is the limiting factor of the fermentation in the toxic selective medium and in the non-toxic selective medium; and selecting at least one yeast strain for which the amount of alcohol produced at time t max in the toxic selective medium is greater than or equal to 65% of the amount of alcohol produced at time t max by said strain in the non-toxic selective medium, wherein t max is the time after fermentation initiation when the maximum amount of alcohol is produced by the yeast strain in the non-toxic selective medium.