1.Impact of different malolactic fermentation inoculation scenarios on Riesling wine aroma.
Knoll C1, Fritsch S, Schnell S, Grossmann M, Krieger-Weber S, du Toit M, Rauhut D. World J Microbiol Biotechnol. 2012 Mar;28(3):1143-53. doi: 10.1007/s11274-011-0917-x. Epub 2011 Oct 29.
During malolactic fermentation (MLF), lactic acid bacteria influence wine aroma and flavour by the production of volatile metabolites and the modification of aroma compounds derived from grapes and yeasts. The present study investigated the impact of different MLF inoculation strategies with two different Oenococcus oeni strains on cool climate Riesling wines and the volatile wine aroma profile. Four different timings were chosen for inoculation with bacteria to conduct MLF in a Riesling must/wine with a high acidity (pH 2.9-3.1). Treatments with simultaneous inoculation showed a reduced total fermentation time (alcoholic and malolactic) compared to the sequential inoculations. No negative impact of simultaneous alcoholic and malolactic fermentation on fermentation success and on the final wine volatile aroma composition was observed. Compared to sequential inoculation, wines with co-inoculation tended to have higher concentrations of ethyl and acetate esters, including acetic acid phenylethylester, acetic acid 3-methylbutylester, butyric acid ethylester, lactic acid ethylester and succinic acid diethylester.