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w i inneeGMAKIN GG w R O WIN S eason 1 Control Délestage A lcohol % (v / v ) TA (g/ L ) Tartaric A cid (g/ L ) Malic A cid (g/ L ) L actic A cid (g/ L ) pH Total Tannin (mg C E / L ) Total Phenol (A U 280 ) Total A nthocy anin (A U 20–A U SO 2) AU 420+ 520 AU 420/ 520 a S eason 2 Control Délestage S eason 3 Control Délestage 12.8aa 6.57a 2.21a trace 3.15a 3.60a 191.6a 12.7a 6.70a 1.97a trace 2.23a 3.66a 173.0b 11.5a 6.20a 3.06a trace 3.35a 3.65a 177a 11.7a 6.38a 3.41a trace 4.07a 3.66a 150b 13.1a 4.85a 1.50a trace 3.87a 3.87a 197.5a 13.1a 4.88a 1.74a trace 2.44a 3.91a 171.1b 59.8a NDb 58.3a ND 43.1a 3.89a 37.6b 3.04b 40.1a 2.37a 37.0b 2.21b 8.23a 0.793a 6.92b 0.780a 8.21a 0.794a 7.82a 0.789b 8.87a 0.575b 7.64a 0.585a D ifferent letters w ithin row s and y ears denote significant difference ( p ≤ 0.05) of treatment means; bN D = not determined; n = 3. 1.2 m) with a screen (2.39 mm diameter holes). Fermentations were conducted at an average liquid temperature of 27º C (range 26º to 33º C) and an average cap temperature of 30º C (range 28º to 34º C). Mechanical punching and délestage were conducted for seven days. Pressing was performed post-dryness (2.0 g/L reducing sugar), 22 days following the beginning of fermentation, with a 5,000-L tank press, by allowing free drainage for one hour, followed by pressing to one bar. Free-run and press-run wines were not combined. Chemical analysis General fruit, must and wine chemistries were conducted as described by B. Zoecklein et al.43 HPLC analysis was conducted 18 months post-fermentation on selected phenols in finished aged wines described by S. Price et al.19 Total tannins (catechin equivalents), and the percentage of color from mono meric pigments (MP), small polymeric pigments (SPP), and large polymeric pigments (LPP) was estimated using the procedures of Adams and Harbertson,1 and Harbertson et al.11 The concentration of total glycosides was estimated by the analysis of glycosyl-glucose in thawed samples as described by P.J. Williams et al.,41 and modified by R.S. Whiton and B.W. Zoecklein.40 Analysis of phenol-free glycosides was conducted as described by B. Zoecklein et al.44 Wine volatiles were analyzed using solid-phase micro-extraction and gas chromatography-mass spectrophotometry, as described by B. Zoecklein et al.43 using a model 5890 GC, model 5972 mass selective detector, and a Carbowax 65-μm fiber. Sensory analysis Discrimination testing was performed on pooled wine replicates of Merlot and Cabernet Sauvignon, using triangle difference comparison described by M. Meilgaard et al.17 The wines were evaluated six to eight months post-fermentation in the Virginia Tech wine sensory laboratory, under controlled conditions that included red lighting to help eliminate color bias. Panel membership required regular wine consumption (at least one glass per week) and attendance at two informational sessions where the methodology of evaluation was described. Evaluation was done based on olfactory (aroma) and retronasal aroma and mouthfeel (referred to as flavor). Evaluations of aroma and flavor occurred at different times. Descriptive analysis was performed nine months post-fermentation on nonpooled Cabernet Sauvignon wine treatment replicates, using 11 trained panelists as described by M. Meilgaard et al. 17 Panel members evaluated three replications of the two products (pigeage and délestage) six times. Panelists had one to 10 years experience in descriptive or consensus sensory analysis. A list of descriptors was developed from three pre-evaluation training sessions with standards used for training prepared as reported by B. Zoecklein et al.43 Merlot results The Merlot fruit averaged 21.5º Brix, 3.7 pH and 5.62 TA for the three years, typical Total phenols Table I : E ffect of manual cap punching (control) and délestage on M erlot wine chemistry for three seasons. 45 40 35 30 25 20 15 10 5 0 Cold soak Control Délestage 1 2 3 4 5 6 Fermentation/post-fermentation day Figure I. Effect of cold soak, fermentation, and post-fermentation on total phenols of control (cap punched) and délestageproduced Merlot wines in season 3; n = 3. of the region. Berries averaged 1.18 g, with 2.4 seeds, for the three years. In years two and three, Merlot fruit monomeric pigments (MP) resulted in an average of 70.5%, while small polymeric pigments (SPP) 19.7% and large polymeric pigments (LPP) 9.8% of the total color. By the end of délestage-treated fermentations, an average 25% of seeds had been removed each year. Fermentation rates were similar among treatments. Total phenols, estimated by the absorbance at 280 nm, increased linearly from crush until dejuicing for both délestage and control wines (Figure I). At day-six (dryness), control lots had a total phenol concentration slightly greater (7.7%) than the délestage (typical of this study). The percentage of color derived from the monomeric pigments was greater in the fruit than the wine, while the percentage of color from polymeric pigment forms showed the opposite trend. Merlot délestage and control wines showed slight differences in the percentage of color from the different pigment sources. Délestage wines produced over three years averaged 4.8% lower color derived from monomeric pigments, 1.4% higher from SPP and 4.5% higher color from LPP, compared to control wines (Figure II). Following fermentation, control and délestage-produced Merlot wines did not differ in alcohol percent (v/v), TA, tartaric, malic, and lactic acids, or pH (Table I). The total tannin concentration was greater in the control wines upon completion of fermentation each year. The total phenol estimations demonstrated a higher concentration in control wines in two of the three years. Total anthocyanins were higher in the control wines in the two years measured, while absorbance at 420 nm + 540 nm, and 420 nm/520 nm, did not demonstrate consistent patterns pr actica l win ery & vin eya r d JANUARY 20 14 47