Please join us at Intervitis Interfructa (Stuttgart, Germany) on 26 March 2010, at the following presentation from Eveline Bartowsky (Australian Wine Research Institute, Australia) on the topic of Influence of malolactic fermentation on the fruity characters of red wine – Bringing wine chemistry and sensory together.

The effects of malolactic fermentation (MLF) on wine aroma profile and chemical properties of Australian Cabernet Sauvignon wine over three vintages were explored by inoculation with up to seven different commercial malolactic starter culture preparations of Oenococcus oeni. The effects of initial wine pH on the sensory and chemical changes arising from the MLF treatments was investigated by adjustment of Cabernet Sauvignon wines to pH 3.3 or pH 3.7 prior to MLF induction. The time required for each malolactic culture to complete MLF varied from 12 – 80 days and was dependent on ML strain, Cabernet Sauvignon style (lighter to more complex) and wine alcohol concentration (13.5-15.5 % v/v alcohol). The sensory properties of the wines were investigated by descriptive sensory analysis, using a trained panel. In support of the sensory data, chemical properties of each wine were determined including phenolics and tannin composition, volatile aroma compounds, and organic acids. Significant sensory and compositional differences occurred as a result of the different MLF treatments, including differences in intensity of perceived fruit flavour. Strain dependent changes in the volatile aroma compounds, including the ester profile, were observed. Increases in total berry fruit esters correlates with increases in fruit related sensory attributes and perception. These trends were observed over the three vintages in Cabernet Sauvignon fruit sourced from the same vineyard. The influence of MLF on fruity wine characters has been extended to Merlot and Pinot Noir in the 2009 vintage.