PT - JOURNAL ARTICLE AU - Sophie C. Ward AU - Paul R. Petrie AU - Trent E. Johnson AU - Paul K. Boss AU - Susan E.P. Bastian TI - Unripe Berries and Petioles in <em>Vitis vinifera</em> cv. Cabernet Sauvignon Fermentations Impact Sensory and Chemical Profiles AID - 10.5344/ajev.2015.15016 DP - 2015 Aug 06 TA - American Journal of Enology and Viticulture PG - ajev.2015.15016 4099 - http://www.ajevonline.org/content/early/2015/08/04/ajev.2015.15016.short 4100 - http://www.ajevonline.org/content/early/2015/08/04/ajev.2015.15016.full AB - Petioles, rachis and leaves are all matter other than grape (MOG) and while originating from vines, they potentially contaminate primary ferments of red grape must. Fruit contaminated with high levels of MOG can be downgraded or rejected at the winery; however management options (including hand harvesting or fruit sorting) can be used to reduce MOG. Petioles are the most common form of MOG to be included in the must, yet little is known of their chemical composition and corresponding effect on the sensory and chemical properties of red wines. A descriptive analysis panel (N = 12) examined Cabernet Sauvignon wines with additions of 0.5% MOG (green berries or petioles) and above. This sensory analysis showed that the presence of 10% petioles in the must, had a perceived impact, increasing floral aromas and reducing bitterness relative to control, while wines made with petioles in the must were fuller bodied relative to wines made with green berries. These sensory results are related to increased terpene concentrations as petioles increase in concentration in the wines’ must. Methoxypyrazines can also be detrimental contaminants to Cabernet Sauvignon wines. The predominant methoxypyrazine in the wines, 3-isobutyl-2-methoxypyrazine, increased in concentration with larger additions of pre-veraison green berries made to the must. Sensory analyses showed wines made with an addition of 0.5% of green berries and above during fermentation were associated with increased perceived acidity, and leafy and vegetal green aromas relative to some wines made with petioles. The results of this study provide winemakers important information to better understand how grape harvesting choices may affect the perceived quality and chemical composition of their wines.