in Malolactic Fermentation of Wines: A Chemical and Sensory Study. Abstractappra/ed; ^ . _ ^-,r —,.

The purposeful induction of malolactic fermentation (MLF) in wines such as Pinot Noir and Chardonnay is an established commercial wine making practice in Oregon. This induction is not always successful, especially with white wines, such as Chardonnay. A study was initiated to examine the compatibility of yeasts commonly used in Oregon winemaking with various strains of malolactic bacteria. In preliminary and pilot plant scale experiments, the yeast strain found to be most conducive to malolactic fermentation by lactic acid bacteria was Montrachet (Red Star). The malolactic bacterial strains that were best able to complete malolactic fermentation in various wines, fermented by different yeast strains, were the two Oregon commercial strains, ER1A and Ey2d, and the Pinot Noir juice isolate, DAPN85A. Sensory analysis of aroma by difference from control test was done on Chardonnay wine fermented by 4 different yeast strains and 3 different malolactic bacterial strains. In all cases, there was an overall significant difference in malolactic fermented wine aroma when compared to control wines. Organic acid analyses by high pressure liquid chromatography (HPLC) and analyses o