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p r a c t i c a l w i n e r y & v i n e ya r d O c t O B e r 2 0 1 4 63 w i n e M A K i n G www.walterjelly.com 608.831.1405 whj wine print.indd 1 2/6/13 5:59:47 PM COLLINWOOD GRAPE CO. 15741 MANDALAY AVE., CLEVELAND, OHIO 44110 216 451 8697 or 216 598 0504 • collinwoodgrape@aol.com www.collinwoodgrape.com We supply quality grapes to the most discriminating wineries. We also supply fresh juices in pails, drums or 275 gal. totes. For the special "Vintners Reserve" we can offer the best grapes. Direct importer of winemaking equipment from Italy. PREMIUM CALIFORNIA GRAPES Specializing in North Coast-Napa, Sonoma, Lake, Mendocino & Sierra Foothills—El Dorado, Amador, Calaveras. WL 1000 900 800 700 600 500 400 300 200 100 0 3 Concentra on in µg/L Figure 1 : Evolu on of oak vola le concentration (µg/ L) in Merlot wine during months (m=month) LT MT MT+ Noise e Special 1 LT MT MT+ Noise e Special LT MT MT+ Noise e Special MT+ Noise e Special 12 12 9 6 3 3 1 12 9 6 3 1 12 9 6 3 1 12 9 6 3 1 12 9 6 1 12 9 6 3 3 1 12 9 6 3 1 12 9 6 3 1 12 9 6 3 1 12 9 6 1 LT MT 9 6 3 3 1 12 9 6 3 1 12 9 6 3 1 12 9 6 3 1 12 9 6 Concentra on in µg/L Concentra on in µg/L Concentra on in µg/L 450 400 350 300 250 200 150 100 50 0 350 300 250 200 150 100 50 0 160 140 120 100 80 60 40 20 0 Vanillin Cis -WL Trans -WL Guaiacol Méthyl -Guaiacol Eugenol+Isoeugenol Furfural Méthyl -Furfural 1 12 9 6 3 3 1 12 9 6 3 1 12 9 6 3 1 12 9 6 3 1 12 9 6 Figure 1. Evolution of oak volatile concentration (µg/L) in Merlot wine during 12 months (1, 3, 6, 9, 12 months). during the first nine or 12 months (Figure 1), and the concentration of 4-methyl- guaiacol was less important. An increase in eugenol content is observed during the maceration time for all wines. Wines with light toast (LT) staves presented the highest concen- trations after 12 months. Both lactones increased linearly in concentration in wine during the oak maturation period (Figure 1), the rate of extraction increasing further from six to nine months, meaning that once a portion of wood is wetted, dis- solution of lactones occurs rapidly. Among phenolic aldehydes, vanillin is considered to have the most important influence on wine aroma. Just as happens with furanic aldehydes, for short aging periods, vanillin accumulates in wine because at the beginning its extraction is high, due to the difference of concentra- tion between the wine and the wood. 2 The biggest concentration is found in the wine with Noisette staves (305.81 µg/L). Similarly to furanic compounds, the lon- ger MT toasting time increases vanillin content. Oak wood total ellagitannin concentration The total ellagitannin level, expressed as milligrams (mg) per liter of released ellagic acid of wine, revealed a large diversity of concentration from 6.31 to 26.07 mg of released ellagic acid per liter (L) of wine (Figure 2). Such differ- ences were expected since ellagitannins undergo thermolytic degradation during the toasting process. 4 Figure 2 shows that, for almost all wines, a maximum extraction of ellagi- tannins is obtained after two to three months. In all wines, after nine and 12 months of contact, the overall concentra- tion of ellagitannins decreased with time. After 12 months, a 10% –20% decrease was observed in ellagitannins levels for