Phenolic Extraction Curves for White Wine Aged in French and American Oak Barrels

Barrels made by the same cooperage firm from French and American wood were put into a study to measure total and non-flavonoid phenolics extraction over time. This experiment was conducted over three fill and empty cycles of the barrel, using white wine. The residence time in the barrels was short, 12 and 16 weeks for the first and second fills, respectively; while the third fill barrels9 aging time was six months. The differences between the French and American woods are dramatic on the first fill, but become less dramatic each fill thereafter. The data, when graphed, show a power curve for the first and second fill barrels indicating diffusion kinetics, but by the third fill, the plot is linear, indicating hydrolysis kinetics. The tasting data show that in spite of the analytical similarities after the first fill, tasters could distinguish between French and American wood even through the third fill.