Brewing With Coffee
Like many homebrewers, I start my day with a cup of coffee rather than a glass of beer. But the roasty, bitter, sweet and earthy flavors I like in coffee are also some of the same flavors I like in beer.
Though I can get some of the same coffee-like flavors from various specialty malts, nothing tastes quite like coffee itself. Using coffee in beer raises many of the same questions one would ask when experimenting with any unusual ingredient. Has anyone done this before? What styles of beer would work well with coffee? What varieties and roasts of coffee would work best? What form of coffee should be used in beer? When should the coffee be added during the brewing process? How much coffee should be used in a typical five-gallon (19-L) batch of homebrew? Will the oils responsible for some of the flavors and aroma of coffee ruin the foamy head on my beer? Let’s get right to the facts and see how we can make this marriage of morning and evening brews work.
To find out if coffee beers have been tried before, I looked into the worlds of both homebrewers and professionals. As it turns out, there are a number of homebrew recipes containing coffee, including several in past issues of BYO. There are also several commercial coffee beers in the U.S. and U.K., including Dogfish Head Craft Brewery’s Chicory Stout, Lakefront Brewery’s Fuel Café Stout, Mill Street Brewery’s Coffee Porter, Bluegrass Brewing’s Heine Brothers Coffee Stout, Thunderhead Brewing’s Espresso Stout, Meantime Brewing and Breakfast Stout from the Founders Brewing Company.
Based on those and other popular examples, it seems the styles that work best with coffee as an ingredient are all on the dark side. Porters and stouts, which already have dark colors and roasty flavors from malts and specialty grains, seem to benefit the most from the addition of coffee. This is not to say that other styles such as brown ale, strong ale, dunkel weizen, altbier, rauchbier, schwarzbier, bock, dark lagers, or others might make interesting candidates for experimentation with coffee as an ingredient.
With these beer styles in mind, what about the coffee itself? Before grabbing that can of Folger’s, let’s look at some different origins of coffee beans and different roasts that affect the flavor of the coffee we might add to our brew. There are two major varieties of coffee grown in the world known as robusta and arabica. A lot of coffee in a can on the supermarket shelf consists of robusta beans roasted to a light or medium degree of darkness. The whole beans you buy in the store or at a coffee shop are usually arabica beans.
Most commercial brewmasters who make a coffee beer say arabica are the beans of choice. A couple breweries even specified that they use coffee from Mexico (Oaxaca), Sumatra (Madheling) and Rwanda. Many (but not all) stay away from dark French or Italian roasts that may produce strong burnt or bitter flavors unless the variety of coffee is low in acidity as part of its flavor profile. Ashton Lewis, Master Brewer at Springfield Brewing said, “We specify that our Mudhouse Stout is made using Sumatra Madheling beans which have a wonderful earthy aroma with very low acidity; we roast our beans very dark and because the beans are low in acidity the result is very rich without the burnt flavors.” Other brewmasters said they prefer coffee roasted closer to the middle of the road that lends more mellowing, nutty flavors. They all felt that roasty or bitter flavors are better achieved and controlled using roasted barley or malt, or appropriate additions of hops.
The coffee I add to my homebrew is arabica I roast myself to the point where the inner oils just begin to appear on the surface of the bean (see accompanying sidebar on the basics of roasting your own coffee). Try arabica beans of various origins until you find one that suits the coffee beer you wish to brew.
At this point you may have a beer style and type of coffee in mind, so how should coffee be added to the brew? Of the brewmasters I spoke to, all said they add the coffee post-boil. Since they wanted coffee flavor and aroma rather than bitterness (which will occur if the coffee is actually boiled) they all preferred to add ground coffee right at the end of the boil or brewed coffee or espresso to the finished beer.
Knowing how to brew a good cup of coffee will definitely help you brew a better coffee beer. Ideally, the water used for brewing coffee should be between 195 °F and 200 °F (90 and 93 °C). For coarsely ground beans, the coffee should be extracted in about 7 minutes; for fine grinds, the extraction should occur in about 2 minutes. (Let your tastebuds be your guide when experimenting with different grinds.) At higher temperatures or longer extraction times, the coffee will be too bitter. At lower temperatures or shorter contact times, the coffee will be weak and insipid. Use two level tablespoons of medium grounds for each five to six ounce (~150–175 mL) cup of coffee you brew.
With these guidelines in mind, freshly ground coffee beans could be added to your wort after turning off the burner and letting the wort temperature drop to around 200 °F (93 °C). Allow the coffee to brew in the wort for a few minutes before quickly cooling the wort.
Alternatively, coffee could be brewed either as coffee or espresso and added to the beer sometime post-boil, preferably at packaging. I brew espresso and add it to my beer at kegging.
To brew espresso, use 0.23 ounces (6.5 g) of finely ground coffee packed firmly — with 20–40 lbs./9–18 kg of downward pressure — into the portafilter of an espresso machine for each one-ounce (30-mL) shot. The espresso machine should deliver water near 195 °F (90 °C) at 130 PSI (9 bar) to extract the espresso in about 25 to 30 seconds.
The next question is quantity. How much coffee to add to a batch of beer is a matter of taste, but there are some guidelines you can use as a starting point. For example, I brew ten 1.5 fluid ounce shots of espresso (for a total of 15 fl. oz./440 mL of espresso) and add them to a five-gallon (19 L) batch of porter or stout at kegging. Many homebrew recipes call for eight to 16 shots of espresso per 5.0-gallon (19-L) batch. I use ten shots as I prefer the coffee as a part of the profile rather than the dominant flavor.
Finally, there’s the question of how oils in coffee will affect beer foam. This does not seem to be a problem when coffee is used in styles of beer that typically produce strong foamy heads like porters or stouts. Using only enough coffee to achieve mellow flavors limits the amount of oil from coffee in the beer, especially in a roast that is not too dark and oily. Oils also float on top of the kegged beer, and since beer is drawn off the bottom, through the dip tube, they don’t do much to limit foam in your glass. I add ten shots of freshly brewed espresso at kegging to my espresso porter and it always has a very good, long-lasting head of foam.
A marriage of coffee and beer is not only possible, but can be a beautiful thing. For your first coffee beer pick a style on the dark side such as a porter or stout that lends itself to coffee flavors. I use a good quality arabica variety of coffee that is not roasted too dark, and keep the coffee as part of the flavor profile without dominating it. Experiment with adding ground coffee immediately after the boil or brewed espresso or coffee to the finished beer. Finally, use this information as a guide to begin experimenting with your own coffee beer and do what homebrewers do best, experiment to make better beer.
Heine Brothers Coffee Stout
(5 gallons/19 L, all-grain)
OG = 1.086 FG = 1.022
IBU = 27 SRM = 66 ABV = 8.4%
Ingredients
14 lbs. (6.4 kg) pale malt
28 oz. (0.79 kg) roasted barley (300 °L)
28 oz. (0.79 kg) flaked oats
12 oz. (340 g) chocolate malt
8.0 oz. (227 g) chocolate wheat malt
1.5 oz. (42 g) ground coffee (0 mins)
6.5 fl. oz. (192 mL) brewed coffee (add to finished beer)
9 AAU Fuggle hops (45 mins) (2 oz./57 g at 4.5% alpha acids)
ale yeast
Step by Step
Mash grains at 153 °F (67 °C) for 90 minutes. Collect seven gallons (27 L) of 1.063 wort. Boil two hours, adding hops during the last 45 minutes.
