Issue link: http://winesandvines.uberflip.com/i/629061
60 WINES&VINES February 2016 WINEMAKING PRACTICAL WINERY & VINEYARD mained uninoculated for a control. At the completion of MLF, different color components were measured, and the wines were aged for nine months, throughout which time color was also assessed. Wine was also produced where the alco- holic and malolactic fermentations were car- ried out simultaneously with the addition of O. oeni VFO at the beginning of the alcoholic fermentation. Lower red color (measured as absorbance at 520 nanometers, or nm) was noted in wines that had undergone MLF com- pared to the control wine, which did not un- dergo MLF (see graphs on page 59). The reduced color persisted throughout aging, as after 270 days there was up to 20% lower red color measured in wines that had undergone MLF compared to the control. Wines that were produced by simultaneous MLF demonstrated the same decrease in color as wines that were inoculated for MLF post- alcoholic fermentation. The lower color in the MLF wines corre- sponded with decreased polymeric pigment and higher concentrations of the more unstable monomeric anthocyanins. Analysis of the wines also revealed that the majority of acet- aldehyde and pyruvic acid was degraded by O. oeni during MLF. Because of the potential role that acetaldehyde and pyruvic acid can play in the formation of color compounds, an addi- tional study was performed to understand the significance of their removal by O. oeni on red wine color development. 5 Pinot Noir wines were inoculated for MLF with O. oeni VFO. At the completion of MLF, acetaldehyde and pyruvic acid concentrations ACETALDEHYDE AND PYRUVIC ACID IMPACT ON COLOR Color at 520nm (left) and polymeric pigment (right) of Pinot Noir wine with restoration of acetaldehyde (A) and/or pyruvic acid (P) after malolactic fermentation at bottling (day zero) and 90 days after bottling. Day 0 Day 90 Storage time (days) Absorbance @ 520 nm 3.5 3.0 2.5 2.0 1.5 1.0 .5 0 n = Control n = Acetaldehyde n = Pyruvate n = A + P n = MLF Day 0 Day 90 Storage time (days) Absorbance @ 520 nm 1.6 1.4 1.2 1.0 .8 .6 .4 .2 0 The references for this article are available online at winesandvines.com Providing leading wine makers with stainless steel barrels of high quality, durability, and design. phone: 773.735.0700 • toll free: 800.441.8780 www.skolnikwine.com • email: sales@skolnik.com Lower red color (measured as absorbance at 520 nm) was noted in wines that had undergone MLF compared to the control wine, which did not undergo MLF.