We know barrel char is a key factor in determining spirit flavor for beer, wine, bourbon and spirits that are aged in barrels. The difference between lighter and darker char levels can cause a huge difference in flavor.

Lighter char levels tend to show more fruit esters and spice notes. The barrel surface is burnt black and showing minimal split in the wood.

Darker char levels will extract more vanilla flavors and color into the spirit. The barrel surface is burnt black and shows a cross hatch pattern with crocodile skin cracking throughout.

Here are some basic points about barrel char levels:

• There are technically 7 levels of charring that can be applied to barrels intended for use in aging spirits. However, No.6 and No.7 levels are rarely used and will usually leave drinks tasting like liquid smoke.
• Char levels are determined by the amount of time flame is applied to the interior of the barrel. Timing determines how much crackling will happen to the interior surface, as well as the amount of sugar and other compounds will be released.
• No.1 Char is 15 seconds.
• No.2 is 30 seconds.
• No.3 (more common) is 35 seconds.
• No.4 Char is 55 seconds. The No.4 Char is also known as the “alligator char,” since after that duration of charring, the interior of the oak wood staves has the rough, shiny texture of alligator skin.
• Char layers tend to be between 1/8 to 1/4” thick.