The legends of how charred barrels came to be the industry standard are numerous. Some are plausible, some are downright ridiculous. But, one thing is certain, whiskey wouldn’t be the same without all the delicious flavors charred barrels impart on our beloved spirit.
But, what exactly does charring a barrel do? How exactly does it benefit the whiskey aging process?
And, now there’s a trend of barrel “toasting.” And, some larger distilleries like Rabbit Hole employ this to give their whiskey unique and desirable flavor notes.
Why Do We Char Barrels?
The reason why we began charring barrels is up in the air. One legend goes that Elijah Craig had a barn fire and rather than lose the cost of the barrels, he put the whiskey into the charred barrels and sent them to his customers anyways. Another goes that barrels were a precious commodity and distilleries saved money by purchasing used barrels and charring the inside to help burn out any residual flavor left behind. One of the most plausible stories is that charring was already used for sugar and distillers took note and utilized the technique for whiskey.
However it started, we now use it because of the chemical and flavor changes it facilitates in whiskey during aging.
Firstly, the wood is opened up by charring the barrels. The barrel expands with heat, and, the heat from the charring process opens the wood. This prepares the barrel to soak up all that delicious whiskey and begin filtering it as well as imparting its flavor into it.
The bourbon will absorb the chemicals from wood, giving it much of its flavor. The sugary caramelization from the barrel also gives some sweeter notes to the whiskey as the alcohol breaks down the charred layer.
Caramel, vanilla, toffee, and spice flavors are all be attributed to these chemical interactions. As the seasons change, the weather affects the passing of whiskey through the wood. When it gets hotter, the whiskey is soaked into the wood. When it gets colder, the whiskey is pushed back into the barrel bringing the wood flavor with it.
Okay, So What Is “Toasting” A Barrel?
Where many barrels are charred, some are toasted first.
Toasting a barrel is using dry-heat to essentially “roast” the barrel. This helps the heat penetrate deeper into the wood. It allows the wood to open even more so the whiskey can soak further into the barrel. It also allows the delicious flavors of the barrel to break down more easily in the alcohol passing in and out of the barrel.
Sometimes distilleries toast barrels before they’re charred. Other times they are simply toasted and used to finish the whiskey after the initial aging.
Some distilleries, like Rabbit Hole, have adopted this process to develop more complex and full flavors in their whiskey. Each step added to the production process adds additional cost. However, not cutting corners and taking every step possible to make a rich and flavorful whiskey is what’s put Rabbit Hole whiskey on the map. Whiskey is a crowded market, and distilleries like Rabbit Hole put incredible time and effort into making sure their whiskey is able to stand out in a crowd.
As the whiskey ages, the toasted barrel absorbs more of the whiskey and changes it at a molecular level. Whiskey slowly converts from a colorless, grain-forward, sometimes harsh spirit into the delicious, smooth, and complex whiskey that will eventually make its way into a Rabbit Hole bottle.
So, now you know.
When you pour a glass of Rabbit Hole whiskey, you know the extra care that went into that glass. You know the barrel was toasted to open it up to convert all that whiskey into something truly complex and delicious.
This is just another example of how Rabbit Hole separates itself from the pack. It prides itself in its intentionality with each step of the whiskey distilling process. Each of these steps compound, amplify throughout the aging process, and come together to create a truly unique whiskey.
If you want to read more about how Rabbit Hole distills its whiskey, you can read about their malting process by clicking here.
Greg Sinadinos started his spirits journey writing a whiskey periodical for Fine Tobacco NYC Magazine. He began answering review requests under a social media page he named “Whiskey Culture,” which quickly merged with Greg’s passion for connecting with others and his interest in history.
Today, Greg travels the country not just looking for great whiskey, but also exploring the history and individuals that the whiskey community is founded upon. He has authored “Whiskey History From Around The World” and is the host of “The Rickhouse” web series.