In the year 1821 Bourbon is first offered for sale in a newspaper in Kentucky. Now what makes Bourbon different from the other whiskeys being distilled at that time is the fact it is aged in charred barrels to add flavor and color to the whiskey. When aging whiskey for a period of time you need a place to store the barrels during the maturation process. Thus was born the whiskey aging warehouse.

These first distilleries were small operations by today’s standards. The distillers were mostly farmer distillers who only distilled part time. Even distillers such as Evan Williams had other interests. For Williams his big business, the one that survived his death, was a brick kiln. He made the bricks for many of the historic homes in Louisville such as Oxmoor and the Farnsley-Kaufman house. These small distilleries probably simply rolled the barrels into the nearby barn or shed. They probably were not there too long as they would sell the barrels to grocers who take passion and store the barrels in their warehouses with their other goods. If enough barrels were gathered in one place they would be stored much like is done in many Scottish warehouses with rails laid upon the top of the first row of barrels and a second layer stored on top. Maybe even a third layer if needed.

Now this storage method has many problems. Additional pressure on the barrels can lead to leaks. It is hard to get barrels on the bottom row (which also tends to be the older whiskey as new barrels end up on top of older barrels as they come into the warehouse). This could be important if leaks do occur and the barrel needs to be fixed. It also limits the air circulation and in Kentucky’s hot and humid summers could lead to musty or moldy tasting whiskey. The environment in the “warehouse” could also affect the whiskey in a negative manner. There may be livestock stored in the same barn at a farm distillery and those smells and flavors could get into the whiskey. A grocery might be storing the whiskey next to barrels of salted fish or pork or pickles and those odors could also get into the whiskey.

As distilleries grew in size they started to build warehouses dedicated to the aging whiskey. Until the 1870s these were simply wooden barn or sheds built for that purpose. Some distilleries went to the trouble and expense of building stone or brick warehouses. However these warehouses were simply dedicated building with storage still on the floor with barrels stacked on top of barrels. As the industrial evolution proceeded forward in the 1800s steam heat could be added to the warehouse but it was an expensive process and most distillers opted for letting nature tack its course.

In 1879 Frederick Stitzel changed the way warehouses were built when he developed the system of barrel racks used at most distilleries today. These “Patent Warehouses” as they are listed on the Sanborn Insurance Maps of the day, had many advantages for aging whiskey. The first is that there was increased air circulation leading to less moldy or musty whiskey barrels. The barrels are under less stress as there no longer other barrels stacked on top of them. It is easier to get to the barrel in case of a leak and should a barrel need to be removed for repair or to be gauged by the government guager, there were fewer barrels to move and therefore fewer labor costs. You could also increase storage by building multi-floored buildings since the rack system was independent of the outer shell of the building. Multistoried buildings caused heat variation in the aging process, which was unknown in the warehouses up to this point of time. The variation could be as much as 60 degrees between the bottom and top floors on a hot summer day.

From 1880 through the 20th century, warehouses would look pretty much the same. They were built multi-storied with barrel racks. They could either be primarily wooden structures clad with sheet metal skins, or they could be brick or stone structures. Many were heated but that usually meant they were also brick or stone buildings. Some distilleries wanted a more uniform aging process and built single story warehouses. Seagram and George Dickel are two examples of this style of warehouse. As Bourbon began to grow in the early 21st century new warehouses were needed. The traditional rack style warehouses were expensive to build and it requires teams of workers to move the barrels into and out of the warehouse, so many companies decided to cut the number of employees needed and save the building expenses of rack and multistoried buildings by palletizing the barrels.

Palletizing barrels leads to many of the problems found with the original storage methods such as barrels stored on top of barrels makes it harder to get to barrels to prevent leaks or to remove individual barrels for any reason. It also has less air flow naturally so distillers usually have a system of fans blowing air through the warehouse to prevent musty whiskey. In addition to these problem there are others. A barrel is not meant to be stacked on end. The pressure is forcing the staves outward, increasing the chance of leaks. It also means one complete head of the barrel is lost for its contribution to the flavor. The head is thinner than the staves and usually not heavily charred so it contributes more vanilla flavors as the whiskey ages. It also changes the chemistry in that instead of having two heads that are partially in a dry state you have one that is constantly dry and the other constantly wet. The dry end also has the problem in that it dries the head completely meaning that when you do turn the barrel on its side for any reason, it will leak through the head.

Finally there is not the heat variation found in the multistoried rack houses with the single story buildings built to palletize barrels.  The big advantages is the lesser cost of building a warehouse and the fact that a single person in the forklift and replace a team of workers moving barrels. Does this storage method change the flavor of the whiskey? That is hard to say because much of the whiskey palletized is still married with whiskey from traditional warehouses so it is hard for the consumer to know exactly what the changes in flavor are with palletized whiskey. It is interesting that since palletized warehouses became more common you have seen less amber color and more straw colored whiskey in the bottle.

The final option that I have seen used by Ted Huber at Starlight Distillery in Indiana and by the Nelson brothers at Nelson’s Green Brier Distillery in Nashville are to use racks that hold two barrels at a time that are designed to be moved by a forklift and to also be staked upon other barrels to create a rack house functionality without the expense. The advantages are that it does increase air circulation around the barrels, it leaves the barrels on their side where they are structurally strongest, and it still allows a single person with a forklift to move inventory. For Ted Huber, the latter is what convinced him to go to this method over the traditional rack warehouse. Too many workers were being injured moving the barrels by hand. The disadvantages are the fact that it means moving a lot of barrels sometimes to get to single barrels on the bottom of a stack and there is still greater pressure on the barrels that could increase the chance of a leak.

The warehouses for aging Bourbon have evolved over the years. There will probably be many other changes experimented with in the future, but I am confident that the methods that make the best whiskey will be the methods that ultimately become the most common.


Photos Courtesy of Maggie Kimberl and Michael Veach