Malolaktische Fermentation in Weinen mit hohen Alkoholgehalt

Malolactic fermentation in wine is characterised by the conversion of malic acid to lactic acid and subsequent changes in aroma and taste profiles. Oenococcus oeni is the species of lactic acid bacteria most frequently associated with malolactic fermentation and used as starter culture to initiate malolactic fermentation. Many strains of this species are well adapted to survive and grow in wine, although wine poses a harsh environment for bacterial growth. Especially the ethanol content in wine disrupts membrane structures of bacteria and affects membran-associated processes, including those involved in malolactic activity. Thus malolactic fermentation is often difficult to be achieved in wine containing ethanol exceeding 15% (v/v). Within this project the malolactic fermentation is evaluated in a high-alcohol wine. Hence, wine is inoculated directly with starter cultures as well as with acclimated starter cultures. The fermentation will be monitored by cultural methods and determination of malic acid degradation and lactic acid production.