The earliest mention I know of about charring barrels to age whiskey is at the Filson Historical Society in the Corliss-Respess Family Papers. It dates from July of 1826 and tells John Corliss that if he will burn or char the inside of the barrel it will improve the whiskey. Charred barrels are a relatively new concept for aging whiskey.
Barrels date back to the early medieval days and are often referred to as the medieval forklift. They made moving goods easier as they could be rolled instead of being carried from place to place. The most expensive barrels made were those made to hold liquids often called “Milk Barrels”. These tightly made barrels were usually made of oak and often charred when used to store water for sea voyages and such. It was determined early on that charred barrels kept the water fresher, longer. As wine production increased so did the use of barrels for aging wine. When Brandy was first produced it was often stored in used wine barrels. This led to the idea of aging Brandy in charred barrels.
In the early part of the 19th century Americans started to age whiskey in barrels to imitate aged brandy. These barrels were 48 gallons in size and were bound by 8 metal or wooden hoops. These barrels were made by hand and the charring of the inside was done by heating the wood over a fire of wood chips made from oak, a by-product of making the staves. The heads were branded with the name of the distiller by heating a metal brand in the fire. The barrels were stored in warehouses stacked on top of each other with the use of rails to roll the barrels.
Barrels were often re-used when possible but the fact is that when a distiller sold barrels to a customer many miles away, the distiller was not going to get the empty barrels back. To make more whiskey they had to purchase more barrels. Some of them could have been used and refurbished barrels but the majority of them were newly made. The result was that the majority of the whiskey was put into brand new barrels. The barrel was the primary package for the sale of whiskey by the distiller so the whiskey was placed into the barrel at a potable strength that ranged from 90-105 proof.
There was no official barrel entry proof. Two years was considered to be mature enough to be called “Straight Whiskey”. The Bottled-in-Bond Act of 1897 made a 4 years old product the most common age for bottled spirits. In 1879 Frederick Stitzel patented a system of racks for storing barrels in the warehouses. These “Patent Warehouses” made it easier to find barrels and move them and increased the air flow around the barrels preventing musty whiskey.
The repeal of Prohibition changed a few things for aging whiskey. The barrel entry proof was made to be no higher than 110 proof. The barrels were required to be brand new charred oak if you wanted to call the spirit “Straight”.
During the Second World War the barrel size was increased to 53 gallons and the hoop number was reduced to 6 hoops in order to save wood and metal for the war effort. The size of 53 gallons was determined because that was as large as they could make the barrels and still have them fit into the barrel racks in the warehouses.
The most recent change in the barrel comes from distilleries is placing the bung hole in the head of the barrel. This change is the result of palletizing barrels for storage. Not many distillers are doing this and its future use will depend upon the effect it has on the aging whiskey. These changes could simply be a failed experiment ten years from now.
The barrel, an old technology, is an important part of giving Bourbon its trademark characteristics. There will never be a fine Bourbon made without barrels.
Photos Courtesy of Maggie Kimberl