How Brewers Are Using Coffee Beans to Make Beer

What happens when your favorite craft brewery decides to make beer… but uses coffee beans as the secret aging agent? In San Diego, brewers are skipping the obvious route of simply adding brewed coffee to beer. Instead, they’re taking unroasted coffee beans and storing them inside barrels that once held bourbon or other spirits — transforming the beans themselves into flavor sponges before a single drop of beer is brewed.

Yes, some breweries age raw green coffee beans in wooden barrels — including those previously used for bourbon — to infuse the beans with wood tannins and alcohol aromas before brewing. This technique is now central to a growing wave of coffee beers that taste more like barrel-aged spirits than a standard cup of joe.

The Coffee-Beer Trend Is Going Barrel First

Coffee beer isn’t new. Breweries around the world have long experimented with blending coffee and beer — using everything from pale ale to stouts, and even rare beans like Kopi Luwak (civet coffee) for ultra-premium batches. But a new method has emerged: treating the coffee beans themselves as the aging medium.

How Barrels Transform Green Coffee Before Brewing

Instead of adding brewed coffee to finished beer, some forward-thinking brewers — notably ModernTimes Brewery and AleSmith in San Diego — are aging green (unroasted) coffee beans directly inside wooden barrels. These barrels might previously have held bourbon or other spirits. As the beans rest, they absorb compounds from the wood and any residual alcohol, picking up intense oak, vanilla, and smoky notes. That flavored coffee is then used in the brew, creating a beer that tastes like it was aged in a barrel itself.

Why Brewers Are Roasting Their Own Coffee for Beer

ModernTimes founder Jacob McKean, a self-described coffee lover and home roaster turned professional, takes the process a step further. His team roasts their own coffee beans in a commercial coffee roaster installed inside their brewery. They pair these beans with their own in-house brewed black beer. McKean didn’t set out to blend coffee and brewing — but after experimenting at home, he began investigating how coffee roasting techniques could complement beer fermentation. The result? A line of coffee beers that are now distributed nationally.

McKean explained that while he never planned to become a coffee roaster, studying third-wave coffee methods helped him understand how to translate roasting profiles and flavor development into the beer world. His approach includes selecting specific coffee varieties and roast levels to match the beer style and barrel history. Every batch uses self-roasted beans and self-brewed base beer to maintain full control over flavor integration.

What Is Barrel-Aging and Why Does It Matter?

Barrel-aging typically refers to storing fermented liquids (like whiskey or wine) inside wooden barrels to impart wood tannins, oxidative notes, and residual spirits. In this new coffee-beer method, the same principle applies — but to green coffee beans. Because green coffee is highly absorbent, it sucks up the volatile compounds in the wood and any leftover alcohol. This creates beans with deep caramel, vanilla, smoky, or even boozy aromas. When these beans are later used to brew coffee-infused beer, the resulting drink carries the complexity of a barrel-aged spirit.

Frequently Asked Questions

How are coffee beans used to make beer?

Brewers either add brewed coffee to beer or — in a newer method — age raw green coffee beans in barrels (often previously used for bourbon) to absorb wood and alcohol flavors. The flavored beans are then used to brew beer, resulting in coffee-forward drinks with rich barrel notes.

What types of beer are mixed with coffee?

Various beer styles are used, from stouts and porters to pale ales and black beers. Some brewers experiment with barrel-aged beers, combining dark roast profiles with bourbon or oak characteristics.

Do brewers actually roast their own coffee for beer?

Yes, some do — like ModernTimes Brewery, which roasts its own beans on a commercial roaster installed at the brewery and pairs them with their own house-brewed black beer for full flavor control.

What is the role of barrels in coffee beer production?

Barrels previously used for spirits like bourbon store green coffee beans, allowing them to absorb wood tannins, vanilla, smokiness, and residual alcohol. This pre-infuses the beans with complex flavors before brewing.

Can you taste the bourbon or barrel in the final coffee beer?

Absolutely. The coffee beans absorb compounds from the barrel, so when they’re brewed into beer, the resulting drink often has pronounced oak, vanilla, and spirit-like notes similar to barrel-aged whiskey.

Recommended FrontStreet Beans for Coffee Beer Experiments

For coffee enthusiasts and brewers experimenting with beer infusions, FrontStreet Coffee’s Brazil Queen Manor (Yellow Bourbon) offers balanced acidity with creamy, peanutty, and chocolatey tones, ideal for mimicking bourbon sweetness. The Rwanda Red Bourbon brings vibrant citrus and floral notes, perfect for bright, acidic coffee beers. Both beans are expertly roasted — the Brazilian at medium depth, the Rwandan lighter — showcasing how roast level shapes flavor. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.