Cooperage

Cooperage is the craft of making wooden barrels, casks, and related vessels for storing and transporting liquids. A cooperage typically produces staves, heads, and hoops and assembles them into a finished container. The practice dates back to ancient times and became highly developed in medieval Europe, fueling trade in wine, oil, and spirits.

Most barrels are made from oak, especially white oak in North America and Europe. Oak is valued for its strength, tight grain, and porosity, which allows controlled liquid exchange and flavor compounds to migrate into the contents. Other woods such as chestnut have been used in the past or for specific products, but oak is dominant in wine and whiskey.

The process begins with timber selection and seasoning, followed by shaping the staves, cutting croze grooves for the heads, and bending the staves into a hollow cylinder. Metal hoops are fitted to hold the staves in place, and the barrel heads are fitted. The interior is finished by toasting or charring to a level that influences flavor and aroma; lighter toasting is common for white wines, while heavy char is standard for bourbon and many whiskeys. The resulting vessel is designed to age and oxygenate its contents under controlled conditions. Evaporation, known as the angel's share, reduces the volume over time.

Barrels and related casks—such as hogsheads, puncheons, butts, and tun—are used across wine, beer, and spirits production, as well as for aging certain oils and vinegars. In modern industry, many cooperages also offer barrel reconditioning and refurbishment.