Chapter 6

Wine Fermentation

Barrel Fermented Wine

Barrel fermentation is the process of fermenting wine in oak barrels instead of large concrete vats or stainlesssteel tanks. This mode of fermentation is only used for those wines which have enough body and structure and are valued for their richness and complexity and is not suitable for young fruity wines for early drinking. Barrel fermentation is especially beneficial to white wines. Barrel fermentation is usually associated with white wine grapes like Chardonnay, but also on occasion with Sauvignon Blanc (e.g., Fume Blanc), and occasionally Chenin Blanc (Figure 6.9). Barrel fermentation of Chardonnay results in a very different flavor profile of the wine compared to tank fermentation.

Barrel Fermentation of Red Wines

Barrel fermentation of red wines is practiced too but requires a lot of work since one the barrel heads have to be removed to insert the must, berries, or clusters. There are essentially two ways to barrel ferment red wines. After removing one of the barrel heads fill the barrel and leave it in a vertical position. New barrels are preferred to impart more oak character to the wines. In this fashion, the barrel serves as a small open-top tank, and cap management is achieved with punch-downs (Figure 6.10).

Advantages and Disadvantages

Yeast viability is enhanced by aeration, enabling the yeast to reproduce more rapidly because it is in its aerobic phase. This gives a quick start to the fermentation and usually results in a higher alcohol in the finished wine. Wine fermented and matured in new oak incorporates less phenolic material than the same wine matured in equivalent barrels after fermentation.

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