Issue link: http://winesandvines.uberflip.com/i/987926
June 2018 WINES&VINES 37 practice with a 40 grams per ton dose of Laffort HE Grand Cru enzyme; and a second treatment of standard practice with a 40 grams per ton dose of Laffort HE Grand Cru and a fermenta- tion tannin addition of 200 ppm Laffort Tanin VR Supra at the crusher and a 300 ppm dose of Laffort Tanin VR Color at 5 o to 7 o Brix deple- tion during fermentation. All other additions, conditions and treat- ments were kept as similar as possible. After primary fermentation in half-ton picking bins, the wines were pressed off and placed in neutral barrels for malolactic fermentation and aging. Samples were taken after primary fermentation, at six months post-fermentation and 12 months post-fermentation. After 12 months in neutral barrels, the wines were bottled under cork and placed in cellar conditions. Trial measurements were standard wine chemistry panels done at Fresno State, HPLC phenolic measurement done at ETS Laborato- ries in St. Helena, Calif., and CIE-LAB and A520 spectrophotometric analysis also done at ETS Laboratories. Sensory evaluation was done in a blind tasting at Fresno State with a 19-member untrained panel consisting of Fresno State winemaking students, faculty and staff and Laffort personnel. Previous studies of enological tannin ap- plication compared to oak chip use in fermen- tation have shown that lasting differentiation occurs after six months, with consistent char- acteristics developed at one year post-fermen- tation. The sampling times of six and 12 months were based upon previous results. The differences between control and treat- ments can be seen in Stabilization and Reten- tion of Color and Tannin, on page 36, where the 12-month time-point amount of color in the enzyme-tannin treatment is 41% greater than in the control and the amount of tannin is 56% greater. As in all red wine aging, color and tan- nin naturally decrease over time. The differ- ences between the six- and 12-month points are due to the reduced amount of color and tannin disappearance. The decrease in the enzyme- tannin treatment is significantly less than in the control and, along with the additional color and tannin extracted and stabilized early in fermen- tation, accounts for the improvement in these two important wine quality characteristics. Looking at some specifics, the basic wine chemistries between control and treatments were not differentiated. The A520 data tracked along with the CIE-LAB data, with the differ- ences reported in the color graph in Stabiliza- tion and Retention of Color and Tannin. The phenolics panel revealed significant differen- tiation, with the control wine analysis set as 100% for all parameters measured (see En- zyme-Tannin Application Effects on Red Wine Phenolics, above). The HE Grand Cru treat- ment shows good extraction of both tannins and anthocyanins, while the enzyme-tannin treatment has an increase in total tannin and catechin due to the 300 ppm addition of Laffort Tanin VR Color (a reactive catechin with ex- tremely low astringency characteristics), as well as a dramatic shift in the amount and distribution of monomeric and polymeric an- thocyanins. The enzyme-tannin treatment re- veals a large shift of monomeric anthocyanins into the pool of polymeric anthocyanins, a much more stable form of the colored com- pounds in red wines. While the chemistry of the trial wines is quite interesting, quantitative evaluations of wine can only get you so far. Sensory evaluation of the wines is critical to understanding the impact of the quality components and characteristics that a trial seeks to impact and measure. The sensory panel determined in a blind tasting that the enzyme-tannin treated wine was preferred by a very wide margin of 79%, compared to 16% for enzyme alone and 5% for the control. There were many other presentations of these trial wines beyond the Fresno State sensory panel, and in less formal settings, the 80% prefer- ence for the enzyme-tannin treated wine held up consistently (data not shown). Comments sug- gested that the color differentiation was so no- ticeable that the naked eye could detect the difference, and the depth of body and intensity of flavors were also noted as differentiating factors. Powerful tools for your winemaking toolbox This specific Merlot trial from the Central Coast may not create a paradigm in wine production, yet it does serve as an example where enologi- cal enzyme and tannin application can act to increase measurable and detectable quality parameters in a wine. The doors left to be opened include the impact these treatments can have on the most important quality parameters of other variet- ies, as well as dose response differentiation under various variety and vintage conditions. The possibility of altering standard winemak- ing practices such as length of cold soaks, post-fermentation macerations, process ap- plications and even yeast selection in response to integrating enzyme-tannin treatments into existing winemaking practices also brings the potential of additional impacts on specific wine quality characteristics. Peter Salamone, an independent consultant, received his Ph.D. from Washington State University and has spent 18 years in both the biotechnology and wine production industries. Shaun Richardson, Laffort USA general manager, has spent 25 years in the wine indus- try, receiving his undergraduate degree in Oenology from the University of Adelaide, and MBA in Wine Business from Sonoma State University. tannin monomeric anthocyanins polymeric anthocyanins quercetin glycosides PRACTICAL WINERY & VINEYARD WINEMAKING To see acknowledgments and references for this article, go to winesandvines.com and search under Magazine › Features › June 2018. Spider graph of phenolic measurables for control versus enzyme-only versus enzyme-tannin treated wines at 12 months post-fermentation. Note the increase in enzyme extractable quality components and the dramatic increase in polymeric anthocyanins versus monomeric anthocyanins in the enzyme-tannin treated wine. ENZYME-TANNIN APPLICATION EFFECTS ON RED WINE PHENOLICS 12 Month Trial Measurement 12 month samples control 12 month samples HEGC 12 month samples HEGC + VR tannins catechin