What kind of barrels is wine aged in?
Oak (wine)
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Oak is used in winemaking to vary the color, flavor, tannin profile and texture of wine. It can be introduced in the form of a barrel during the fermentation or aging periods, or as free-floating chips or staves added to wine fermented in a vessel like stainless steel. Oak barrels can impart other qualities to wine through evaporation and low level exposure to oxygen.[1]