Tradition: Before industrialization popularized the use of metal fermenters and tanks, beer was aged in barrels. This tradition was preserved and lives today among Belgian brewers of Lambic and sour ales. Through the centuries, they use and re-used barrels (mostly oak) to ferment and age their beers, masterfully blending batches from different barrels and years to achieve their ideal result.
Taste: The three most common types of oak used by brewers are American, French and Hungarian, each with its own balance of flavor and complexity. Oak is full of flavorful and aromatic compounds that can add depth and complexity to beers. Flavor components may include caramel, clove, vanilla, coconut, cinnamon, and toast.