My introduction to barrel-aged coffee came through a blog post from Modern Times Beer. In case you haven't had the chance to educate yourself on the process, here it is simplified: Unroasted coffee beans are placed in used bourbon/whiskey barrels, in which the highly-absorptive "green" beans soak up an array of flavors and aromas provided by the barrel. The beans are then subsequently roasted enclosing those unique qualities imparted by the barrel. Just reading about the process and results immediately made me want to start experimenting.

I've brewed with non-barrel-aged coffee across multiple styles (usually stouts, porters, and cream ales) employing different methods of "dry-beaning" or titrating cold brew directly into the keg–all with variable results. With that in consideration, I wanted to take careful steps to create a satisfactory product that could be replicated in future practice.

Before brewing, I wanted to understand the raw materials at hand. After ordering a few 6-oz bags of barrel-aged beans from Spent Planet Fermentation, I made a 6 oz batch of cold brew coffee. I utilized a toddy method, in which the coarsely-grounded beans soaked in 32 ounces of room temperature water. However, I only allowed the soak to last approximately 8 hours. From previous experience, a 6-12 hour soak with coarsely-grounded beans extracts the beans' pleasant flavors and aromas while staving off the harsh tannins one can get with too much contact time. Furthermore, I opted to bypass dry-beaning. As per my experience, the direct exposure of beans within an alcoholic solution (as opposed to water alone) draws out more robust, yet pleasant aroma and flavor molecules, excessive tannins are concurrently drawn into the solution regardless of contact time.

The cold brew qualities alone were exceptional. Aromas jumped out of the glass even when it was chilled to normal beer pouring temperatures! Notes of mocha were softly lifted by a distinct spirit-derived character. Barrel and bean tannins were present but welcoming, void of any roughness. Additionally, a faint vanilla and coconut flavor added a touch of sweetness. Even over the next few days, a small pour of cold brew yielded whiskey notes that remained intact and supportive of the coffee's nuanced characteristics. Bear with me, but it wasn't the type of eye-opening beverage you'd crave on a summer morning. The qualities obtained from the barrel cause the coffee to deviate from your typical sunrise stimulant and give it more of an afternoon "pick me up" attribute– an attribute that makes it destined for beer.

And into beer it shall go.

RECIPE SPECS:

Batch Size: 5 Gallons

SRM: (estimated per BeerSmith) 45

IBU: (estimated per BeerSmith) 57

Anticipated OG: 1.080

Anticipated FG: 1.023

Anticipated ABV: 7.4%

Actual OG: 1.079

Actual FG: 1.025

Actual ABV: 7.1%

Grain:

Maris Otter: 69%, Munich: 15%, Chocolate Wheat: 8%, Brown Malt: 3%. C-40: 2%, C-120: 2%, Carafa III: 1%

Hops:

Magnum (13.3%) at 60 minutes

Yeast:

Denny's Favorite (Wyeast 1450) - 2 L starter made 2 days prior to brewing.

Water Profile: 100% Ozarka Natural Spring Water treated with Gypsum 4g, CaCl2 10 g, NaHCO3 8g for a calculated pH of 5.6.

Chloride/Sulfate Ratio: 2.27

Mash/Sparge Schedule:

Dough-In @ 104ºF (20 minutes)

Protein Rest @ 122ºF (10 minutes)

Saccharification Rest @ 154ºF (60 minutes) with Mash pH taken at 20 minutes (pH = 5.59)

Mash-Out @ 168ºF (Drained to BK when temp reached) and drained into Boil Kettle

Notes:

Recipe was brewed on an electric recirculation system. No sparge was utilized.

90 minute boil performed appropriately.

Cooled to 60ºF

Whirlpool performed for 15 minutes and subsequently rested for 15 minutes to separate wort from trub, then collected into fermentor.

64ºF yeast pitched into 63ºF wort

Fermentation started at 63ºF. On day 3, a gradual rise to 69ºF was performed over 24 hours and maintained until day 13.

After no activity was noted in the bubbler and gravity remained stable over 2 days, beer was cold-crashed to 46ºF and remained at this temperature for 2 days prior to kegging.

During the cold-crash, cold brew coffee was made with 12 ounces of coarsely-ground barrel-aged beans. I soaked the beans in 64 ounces of water using a toddy, allowing a contact time of approximately 8 hours. Thereafter, I drained the cold brew from the spent grounds and allowed the liquid to rest for 24 hours so the flavors could meld.

The following day, I pulled 12 ounces of the beer from the conical and separated them into 3 vessels, each containing 4 ounces of beer. I then titrated different amount of cold brew (in milliliters) into the samples to gauge the amount of coffee needed to place into the keg. After careful deliberation, I settled on 5ml/4oz of beer ( equating to approximately 26 ounces per 5 gallons).

26 ounces of cold brew were poured into a freshly-sanitized keg, the keg was then purged with CO2, and beer was then racked onto the coffee.

The keg was then cold-crashed for 24 hours at 38ºF.

The following day, I force carbonated the beer to 1.8 psi and then placed the beer on my nitrogen tap.

Results & Discussion:

Aroma: Assertive cacao and java notes up front, almost as if coffee grounds were sitting in the glass. A subtle maltiness nudges through but is almost eclipsed by the cold brew.

Appearance: Ink. When poured, the nitrogen displays an array of chestnut bubbles that settle into a tawny, tightly-packed head.

Flavor: Unique, to say the least. The oak and spirit-derived flavors display themselves in a more subtle way than true barrel-aged beers. Mocha and baker's chocolate are bold but not heavy-handed. A delicate vanilla sweetness is faint but welcomed. Tannins, whether they orginiated from the barrel or bean, abate the beer's sweetness without assaulting the tongue.

Mouthfeel: Big and velvety. The nitrogen softens any rough edges giving the beer a pleasing texture.

Future Changes:

I feel pretty good about this one.

Carbonation Issues: The next go-around, I'd like to brew it with a small amount of lactose and place the beer on 2.3 volumes of CO2 alone. This may assist in softening the mouthfeel, mimicking the silkiness provided by the nitrogen.

Mineral Changes: For this beer, I opted to keep Chloride/Sulate ratio much higher, to accentuate the malt-derived flavors. Although only a bit of the Maris Otter malty character pushed through, I feel that the ratio contributed a roundness to the mouthfeel. Additionally, the mash pH was kept on the high side of optimal, to temper any acidity imparted by the coffee.

Grist Bill: I was fairly happy with the grain. Usually, my porters and stouts contain about 13-14% roasted malt. However, I dropped it to approximately 12% to make room for the roasted notes imparted by the coffee. I also scaled back my crystal malts a tad bit due to an expected residual sweetness from a higher-than-normal mash temperature

Yeast: It may be the last time I use Denny's Favorite in a dark beer. I continue to see fickle results with attenuation. Although this beer is enjoyable, it finished out a couple points higher than expected.