1) Blackening 2) Chemical process 
Charring is a chemical process of incomplete combustion of certain solids when subjected to high heat. The resulting residue matter is called char. By the action of heat, charring removes hydrogen and oxygen from the solid, so that the remaining char is composed primarily of carbon. Polymers like thermoset or most solid organic compounds like wood...
• (p. pr. & vb. n.) of Char
As part of the cask making process the insides of the new American barrels are exposed to flames. This chars the inside of the barrel and adds to the flavour of the whisky as sweet sediment is released from the wood.
The act of firing the interior of an oak cask. This technique is of key importance in the production of bourbon and a charred barrel imparts a sweetness to the spirit as well as vanilla.
English designation (charring) for extreme toasting of barrique barrels. The wood is exposed to fire or heat for a very long time, so that the surface turns black. Such barrels are usually only used for spirits such as cognac, rum whisky and others. See under Toasting.
Blasting the inside of a barrel with fire to create char.
The inside surfaces of new barrels are exposed to flames as part of the barrel-making process. This charring affects the flavour and colour of the spirit aged in the barrel. Old barrels are sometimes re-charred to prolong their useful life.
The process of charring the inside of barrels. The contact of the flame opens fissures that help with the aging process. It does not colour the whisky.
Firing and extinguishing of casks with a bright flame and water to produce a layer of charcoal.
The act of burning the inside of an oak cask. American whiskey must be matured in charred oak casks. In Scotland, charring is used as a way of re-generating an old cask.