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February 2016 WINES&VINES 61 PRACTICAL WINERY & VINEYARD WINEMAKING were measured in these wines as well as a control wine that did not undergo MLF. Acet- aldehyde or pyruvic acid was then added back to the MLF wines so as to equal the concentra- tion measured in the control wine. Color was assessed at zero and 90 days aging. While addition of pyruvic acid did not significantly impact color, addition of acetal- dehyde reduced the amount of color difference between the control wine and MLF wines (see graphs on page 60). This was also reflected in the amount of polymeric pigment and mono- meric anthocyanins in these wines. Wines where acetaldehyde had been added back had significantly higher polymeric con- tent than MLF wines that had no addition. For example: After 90 days of aging, MLF wine with no addition had approximately 41% less polymeric pigment than the control wine, while the acetaldehyde addition treatment only had an 18% reduction. Delaying MLF to improve color One strategy that winemakers adopt to im- prove Pinot Noir color is to delay MLF. Anec- dotally, winemakers have reported that long or delayed MLF tends to produce wines with greater color. This observation was investi- gated by delaying MLF for up to six months. 5 Although delaying MLF did not have a signifi- cant impact on color loss at 520 nm (see graphs above), it did impact the formation of poly- meric pigments. As MLF was delayed for longer periods of time, the polymeric pigment content and mo- nomeric anthocyanin concentration of wines that underwent MLF became more similar to those of the control. In fact, when MLF was delayed for 200 days, the polymeric pigment DELAYED MALOLACTIC FERMENTATION AND WINE COLOR Day 0 Day 100 Day 200 Day 28 Day 14 Absorbance @ 520 nm 3.5 3.0 2.5 2.0 1.5 1.0 .5 0 Day 0 Day 100 Day 200 Day 28 Day 14 Absorbance @ 520 nm 1.4 1.2 1.0 .8 .6 .4 .2 0 Day 0 Day 100 Day 200 Day 28 Day 14 Monomeric anthocyanins (mg/L M-3-G eqs.) 70 60 50 40 30 20 10 0 n = Control n = MLF Color at 520nm (left), polymeric pigment (middle), and monomeric anthocyanins concentration (right) of Pinot Noir wines that underwent malolactic fermentation delayed for set period of time.