Peculiarities of flor strains adapted to Sardinian sherry-like wine ageing conditions

Saccharomyces cerevisiae flor yeasts, which are subjected to stressful conditions during wine ageing, exhibit a number of characteristics which distinguish them from non flor S. cerevisiae wine strains. In the present work, 22 flor and 14 non flor S. cerevisiae wine strains are compared, in order to elucidate other possible peculiarities of these yeasts. The results obtained demonstrate that in contrast to the homothallic nature of the non-flor strains, 77% of the flor strains exhibit two variants of a semi-homothallic life cycle. Moreover, the floc-forming ability is shown to be inversely correlated to spore viability and the utilisation of maltose and galactose. (c) 2005 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.