The use of oak plays a significant role in winemaking and can have a profound effect on the resulting wine, affecting the color, flavor, tannin profile and texture of the wine. Wines can be barrel fermented in oak or they can be placed in oak after fermentation for a period of aging or maturation. Wine that is matured in oak receives more of the oak flavors and properties than wine that is fermented in oak.
Different batches of wine can be mixed before bottling in order to achieve the desired taste. The winemaker can correct perceived inadequacies by mixing wines from different grapes and batches that were produced under different conditions. These adjustments can be as simple as adjusting acid or tannin levels, to as complex as blending different varieties or vintages to achieve a consistent taste.