Why New, Charred Barrels?

By Chris Morris • Photo By Shutterstock & Headshot By Matt Johnson 

In a recent issue of the Voice, we discussed the reason why whiskey barrels are made from oak. Again, the answer was one of practicality, barrels made from oak hold liquids while those made from other woods do not. There always seems to be a practical reason for many of the historic rules, regulations and practices that govern the world of spirits and specifically those that are unique to the world of whiskey. 

If you recall in our exploration of international whiskey types that Scotch, Irish, Japanese, and other whiskey classifications simply require the use of oak barrels as part of their standards of identity. No specification about the condition of the oak barrel is stated. However, we know that Bourbon is specifically required to age in new, charred oak barrels. Why that difference? Again, the answer can be found in time and place. 

Let us start from the beginning. To make a barrel from slats of oak, which are called staves, first a tree must be felled. An oak tree contains a vast amount of water, just like the human body does. So, the next thing a stave mill must do is cut the trunk of the oak into rough staves and allow them to dry. 

Why? If a barrel was made from green wood eventually it would dry out, shrink and the barrel would no longer be able to hold liquid. Anyone who has tried to saw wet wood knows how hard it is to do so. The wood will grab the saw and the wood’s edges will fur. But when the wood has reached the desired degree of dryness, it can be machined into the shapes and sizes needed to craft a barrel. 

Next the Cooper (the barrel maker) will assemble the staves into the shape of the barrel on one end using a temporary hoop. The staves at that end of the barrel will be tightly fitted while the other will have its staves splayed outward like an open hand. To close that the splayed ends must be drawn together. Any attempt to do that at this point will result in the staves cracking and splitting. This is because the oak staves are very dry and straight. The solution to this problem answer can be found in the form of heat and moisture. 

I have visited a colonial era cooperage reenactment in Williamsburg, Virginia, and observed how barrels were made at the time of Kentucky’s settlement in the mid-1770’s. Coopers historically raised (built) a barrel around a small fire or a pot filled with hot coals to heat the wood. Periodically they would swab the barrel’s interior as it got hot with a wet mop. 

As the wood becomes moist and warm, it regains flexibility which allows the Cooper to pull the splayed staves at the open end of the barrel together so that another hoop can be affixed. Doing this over a fire or pot of coals occasionally resulted in the staves catching fire. The cooper would easily extinguish it with another application of the wet mop. Therefore, during the manufacturing process some barrels were inadvertently charred. 

In the early days of the development of Scotch and Irish whiskies, the raw spirit was stored in either ceramic containers or used oak barrels. Due to the fact that their market was the local population once a barrel was emptied it would be reused. Plus, the oak forests of Scotland and Ireland had long been exhausted – so new wood was very hard to come by. Therefore, Scotch, and Irish whiskey have a tradition of reusing barrels. 

In frontier Kentucky conditions were different. The state was blanketed with a vast hardwood forest teaming with oak trees, so wood was in plentiful supply. Kentucky’s early population was small and the whiskey it made had to be shipped via the river system to the markets on the East Coast for it to find buyers. Therefore, barrels left and never returned. So, the industry was forced to use new barrels. 

It was after the long journey to the East Coast that the benefit of aging in a new, sometimes charred barrel was discovered. The Filson Historical Society’s archives contain correspondence from customers on the East Coast to their suppliers in Kentucky. As early as the 1820’s these eastern merchants had recognized that the Bourbon shipped from Kentucky in barrels that had charred wood in them tasted better than that shipped in uncharred barrels. How did they determine this? The answer, while one of conjecture, must be a simple one. Say two barrels from the same distillery arrived at the customer’s place of business, a tavern in Savannah, after the long voyage. The Bourbon in one was lightly straw colored with a prominent raw wood flavor while the other held a darker, sweeter, more palatable liquid. Once the barrels were emptied the proprietor, out of curiosity, opened them to look inside and discovered that the better Bourbon came from a barrel that had charred wood in it. As a result of this discovery the customer requested that charred barrels be used in their next order. Slowly but surely this knowledge spread throughout the Kentucky Bourbon industry. At some point during the mid-1800’s (we may never know the exact date) Dr. James Christopher Crow, the Master Distiller at what is now the Woodford Reserve Distillery, became the industry champion for using new, charred barrels in the production of Bourbon. In 1935, this recommendation finally became law as the US standards of identity were approved by the federal government. Sometimes the best things in life occur by accident.