Barrel Like with other spirits, longer aging results in a more pronounced flavor. Traditional balsamic vinegar is aged in a series of wooden barrels. Since its invention in 1868, the pepper mash used to make Tabasco sauce is aged for three years in previously used oak whisky barrels. Beers are sometimes aged in barrels which were previously used for maturing wines or spirits. This is most common in darker beers such as stout, which is sometimes aged in oak barrels identical to those used for whisky. Whisky distiller Jameson notably purchases barrels used by Franciscan Well brewery for their Shandon Stout
Whisky in wood for a similar time. After a decade or two, additional aging in a barrel does not necessarily improve a whisky. While aging in wooden casks, especially American oak and French oak casks, whisky undergoes six processes that contribute to its final flavor: extraction, evaporation, oxidation, concentration, filtration, and colouration. Extraction in particular results in whisky acquiring a number of compounds, including aldehydes and acids such as vanillin, vanillic acid, and syringaldehyde. Distillers will sometimes age their whiskey in barrels previously used to age other spirits, such as rum or sherry, to impart particular flavours. Most whiskies are sold