Ah, the warm, sweet, oaky smell of bourbon whiskey. If you’re a lover of craft/specialty coffees, chances are good that you also appreciate craft beer and/or craft spirits. That’s certainly the case for me, which is why as a specialty coffee roaster I’ve been an avid collaborator with craft brewers and distillers in my business. The most popular product of mine from these collaborations is what I call The Stumbling Monkey, a bourbon+beer barrel-aged Colombian coffee that I produce twice a year in the spring and fall.
How Is Barrel-Aged Coffee Made?
As you might guess, it all starts with the right barrel. For the Spring 2018 release of Stumbling Monkey, we used a bourbon barrel from Cedar Ridge Distillery in nearby Swisher, Iowa, which Lion Bridge then used to age a Russian imperial stout. This is the first time I’ve been able to use an “All Iowa” barrel, and both companies were excited and supportive to see a third local maker keep creating goodness with the barrel.
My aging process for the un-roasted coffee beans is 4-6 weeks. I load 150lbs (1 whole grain sack) of the beans into the open barrel, re-seal it, set it on its side, and then every other day or so I roll it around my shop floor to help evenly distribute the moisture absorption through the coffee beans. The beans act like dense little sponges, and absorb much of the moisture in the barrel’s interior and extracting moisture from the oak. With so much moisture absorbed from the barrel, this essentially “cashes out” the barrel and prevents any subsequent uses (at least for aging more coffee beans).
When unloaded from the barrel, the beans are ready for roasting. Their moisture content has changed significantly in the 4-6 weeks, which does dramatically impact the roasting process, but I’ve developed a roast profile that successfully accounts for this change.
Just As Important: How Is Barrel-Aged Coffee Named?
The first time I produced it, I came up with the name “The Stumbling Monkey” based on the names of the previous uses for the barrel. Originally housing a Wild Turkey bourbon, the oak barrel was then purchased by Lion Bridge Brewing Co. in Cedar Rapids, Iowa, an hour from my roastery. Lion Bridge then aged a fall seasonal brown ale and named it “Gobble Wobble.” Thanksgiving…turkey…booze… Get it?! 🙂 – So when the barrel was emptied of beer, I purchased it to age green/un-roasted coffee beans and continued the “inebriated animal” metaphor. The name has been almost as popular as the coffee itself.
What Does Barrel-Aged Coffee Taste Like?
So what’s this stuff actually taste like? Well, it’s what I like to call “a complex mouth journey.” There are different aromas and tastes that present themselves at different points of the grinding, brewing, drinking, and finishing process.
The whole beans and dry grounds give off a strong sweet vanilla and caramel aroma that is a touch boozy. If you’re brewing as pour-over and can smell the wet grounds as the hot water is extracting the oils, you start to pick up on the oak barrel characteristics in the aromatics, along with (still) the booziness. In the cup itself, you taste a balance of chocolate, oak, and vanilla. In the finish, the wood lingers and a slight note of the bourbon becomes apparent. In terms of the roast color spectrum, this is what I call a “Medium-Dark” roast, which tends to highlight the chocolate and oak flavors, and received the widest support from my early taste testers.
This coffee also makes for an amazingcold brew experience! With a 12-hour cold brew extraction, you’re left with a boozy cold coffee concentrate that lends itself well to milk/cream and sugar…or Bailey’s Irish Cream! 🙂
Is There Only One Correct Way To Barrel-Age Coffee?
Some may be thinking: Why bourbon, then beer, before coffee? My first ever barrel-aging project was a single-use bourbon barrel, and the booziness was sointense that it gave the coffee a very hard edge. My second batch introduced beer in between the bourbon and coffee, and my own taste tests along with feedback from repeat tasters indicated that the beer mellowed out and sweetened the overall flavor experience while still maintaining the oak and boozy characteristics.
That being said: No, there isn’t one single “best” way to make barrel-aged coffee.
All in all, The Stumbling Monkey is an interesting beast from both a production and consumption perspective. It’s a fun project that always gets people excited, so it’s one that I look forward to as a roaster. I hope you enjoy the mouth journey as much as I enjoyed the production journey!
About The Author: Brian Gumm is owner and head roaster at Ross Street Roasting Co. in Toledo, Iowa. Ross Street roasts delicious seasonal single-origin coffees, year-round staples, and unique one-offs like you’ll learn about in this article.