RT Journal Article
SR Electronic
T1 Effects of Cap and Overall Fermentation Temperature on Phenolic Extraction in Cabernet Sauvignon Fermentations
JF American Journal of Enology and Viticulture
JO Am. J. Enol. Vitic.
FD American Society for Enology and Viticulture
SP ajev.2015.14129
DO 10.5344/ajev.2015.14129
A1 Larry Lerno
A1 Max Reichwage
A1 Ravi Ponangi
A1 Leanne Hearne
A1 David E. Block
A1 Anita Oberholster
YR 2015
UL http://www.ajevonline.org/content/early/2015/06/12/ajev.2015.14129.abstract
AB The phenolic content of red wine is responsible for the color, mouthfeel, and aging potential of the wine. While many fermentation parameters and winemaking techniques have been shown to affect phenolic extraction it is generally agreed that one of the prime factors is fermentation temperature; however, temperature is not uniform during the course of the fermentation, with thermal gradients forming between the cap and the liquid portion. To determine the effects of temperature on phenolic extraction research scale (120 L) Cabernet Sauvignon fermentations were performed in which the cap and must were either maintained at the same temperature or a constant thermal gradient was maintained between the two during the period of active fermentation. All fermentations were sampled twice daily and phenolic content was determined by reverse-phase HPLC for monomeric phenolics and UV-VIS spectroscopy for total anthocyanins and condensed tannins. These experiments showed that cap and must temperature have noticeable effects on phenolic extraction based on where the phenolics originated. For skin phenolics temperature affected primarily the rate of extraction but not the final concentration, with increasing temperatures favoring faster extraction. For seed phenolics increases in fermentation temperature increased both the rate of extraction and also the final concentration. Comparison of the extraction data for the two sets of fermentations showed that must temperature, rather than cap temperature, appears to be more important in driving extraction.