Prior to storing wine, oak barrels are toasted – their insides lit on fire, to as to produce a moderate layer of charcoal – which helps draw out qualities of the oak, seal the wood, and provide a neutral butter between the wine and “raw” wood in the rest of the barrel.
Based on how long a barrel is toasted, different qualities will show through in the aging wines it holds.
A wine barrel toast of 10 to 15 minutes will add spice to a wine.
A wine barrel toast of 15 to 30 minutes will expose sweeter, sugary aromas from the wood, such as butter and vanilla.
A wine barrel toast of 30 to 45 minutes will show darker, earthier aromas such as smoke, tobacco, and coffee.
Depending on a winemaker’s desired results, barrels of different toasts will be used to age specific wines.