Oak barrel charring and toasting are two different processes that are used to prepare oak barrels for aging wine and spirits. Both processes serve to soften the tannins in the wood and to add flavour compounds to the liquid that will be aged in the barrel.
Charring is the process of burning the inside of the barrel with an open flame. This process creates a layer of charcoal on the inside of the barrel, which acts as a filter to remove harsh tannins and imparts flavours like smoky, toasted and vanilla notes. The level of charring can vary and is usually classified into levels such as light, medium and heavy char. A light char will result in a softer, more delicate flavour profile, while a heavy char will result in a bolder, more pronounced flavour profile. Charring is mainly used in the production of spirits like bourbon, scotch and whiskey.
Toasting, on the other hand, is the process of heating the inside of the barrel with a controlled flame. This process also softens the tannins in the wood and imparts flavours like vanilla, caramel, and spices. The level of toasting can vary and is usually classified into levels such as light, medium and heavy toast. A light toast will result in a softer, more delicate flavour profile, while a heavy toast will result in a bolder, more pronounced flavour profile. Toasting is mainly used in the production of wine, particularly red wine.
The main difference between the two processes is the level of charring and toasting and the type of final product that the oak barrel is used for. Charring is mainly used for spirits, while toasting is mainly used for wine.