TY - JOUR T1 - The Extraction of Volatile Compounds From French and American Oak Barrels in Chardonnay During Three Successive Vintages JF - American Journal of Enology and Viticulture JO - Am J Enol Vitic. SP - 163 LP - 172 DO - 10.5344/ajev.1996.47.2.163 VL - 47 IS - 2 AU - John P. Towey AU - Andrew L. Waterhouse Y1 - 1996/01/01 UR - http://www.ajevonline.org/content/47/2/163.abstract N2 - Fifteen barrel lots — 7 American, 6 French and 2 Hungarian — each containing 10 barrels, were used for the fermentation and sur lies aging (7 months) of Chardonnay wines in three consecutive vintages (1992, 1993, and 1994). Barrel samples were taken periodically throughout the aging process and after filtration and bottling each year. Each wine sample was extracted with dichloromethane and concentrated under nitrogen gas before analysis by capillary gas chromatography. Twenty-five compounds were identified including, 10 compounds generally recognized in the literature as being oak-related. It was found that the extraction of each oak-related compound from the barrels into the wine followed a curve unique to that compound and that extraction rates were lower in the one-year-old barrels than in the new barrels. These curves reflected an exponential approach to a limit, suggesting that extraction is diffusion-controlled. Extraction rates were slower in year 2 than in year 1. In comparing data from the two successive vintages, concentrations of most oak-related compounds, especially those related to toasting, decreased significantly in the second year. However, levels of ß-methyl-γ-octalactone, particularly the cis isomer (the more important isomer in sensory terms), were significantly higher in the wines aged in the one-year-old barrels. However, in the two-year-old barrels (year 3 of the experiment), ß-methyl-γ-octalactone, concentrations decreased to levels lower than those found in year 1. ER -