TY - JOUR T1 - Reduction of Malic Acid in Wine Using Natural and Genetically Enhanced Microorganisms JF - American Journal of Enology and Viticulture JO - Am J Enol Vitic. SP - 341 LP - 345 DO - 10.5344/ajev.2007.58.3.341 VL - 58 IS - 3 AU - Gary L. Main AU - Renee T. Threlfall AU - Justin R. Morris Y1 - 2007/09/01 UR - http://www.ajevonline.org/content/58/3/341.abstract N2 - Naturally selected yeast ICV-GRE and 71B, malolactic bacteria Lalvin 31, and genetically enhanced yeast ML01 were compared for biodeacidification of malic acid in production of Vignoles wines. ICV-GRE yeast consumed 18% of malic acid with no lactic acid production. Lalvin 31 added to the wine fermented with ICV-GRE converted the remainder of the malic acid to lactic acid and consumed some citric acid. The ICV-GRE + Lalvin 31 treatment produced less lactic acid compared with the ML01 treatment due to malic acid consumption by the ICV-GRE yeast and had the lowest titratable acidity. ML01 was effective at converting 5.7 g/L (100%) malic to lactic acid during the first 60 hr of fermentation. The 71B yeast consumed 1.9 g/L (33%) of the malic acid with no lactic acid production. Wine produced with ML01 had higher levels of total sulfur dioxide (SO2) than the other treatments. A secondary experiment found that the ML01 yeast produced 34.6 mg/L SO2, which was three times as much as produced by ML01 yeast could be of ICV-GRE and six times as much as 71B. The amount of lactic acid and SO2 concern to enologists depending on style of wine desired. ER -