There are several different methods in which coffee can be added to a beer. I’ve had great success with two different methods: adding cold pressed coffee at bottling/kegging and dry-hopping with whole coffee beans. It’s important to remember that not just any coffee bean will work with your beer. Trying the base beer to get an idea of what flavors and aromas it has, greatly helps in trying to find a coffee that will either complement it or add enough contrast without being lopsided. I am only going to touch on the methods I have tried. You could also try adding coffee during the boil or during the mash, among many other methods.
Dry Hopping with Whole Coffee Beans
For my first coffee beer I followed a clone recipe of Wake n Bake as explained by Terrapin’s Spike Buckowski on The Brewing Network. To make it even easier to clone, Terrapin sells the exact Jittery Joe’s blend that they use in the beer right on their website.
Beyond my normal sanitation practices, I didn’t do anything special to the beans. After primary fermentation was complete I sanitized a 5 gallon glass carboy and added 3 ounces of whole beans directly to the bottom of the carboy. I racked the beer on top of the beans, threw an airlock on top and let it sit for 3 days. I read from several sources to basically let the beer sit until it gets the flavor you want. Despite the short contact time, the beer had a huge coffee aroma and flavor after it was bottled and conditioned. I recently opened up the last bottle which was over a year old and to my surprise the beer still packed the coffee punch.
I didn’t encounter any issues with head retention due to the oils of the beans, despite various sources mentioning that this could happen. Overall I was very pleased with this method, although at a large scale brewery, this would be an expensive and non-feasible option. At the homebrew level it’s not really an issue.
It wasn’t until a month or so after I moved to Portland that I learned about the french press. This amazing device makes exceptional coffee, I may never go back to my drip machine!
The idea of cold-pressing the coffee involves grinding the beans and using a 4:1 ratio of water to ground coffee and instead of heating water up, you simply use cold water. It takes a bit longer to extract all of the essential oils from the ground coffee, so beforehand I sanatized my french press, added the ground coffee, added the water, stirred, and put some plastic wrap over top. I then placed the french press in my refrigerator for approximately 24 hours. Right before racking my oatmeal coffee stout into the keg I pressed the grounds and poured off the coffee into the keg, racking the beer on top of it.
The flavor from cold-pressed coffee is even stronger then using beans for dry-hopping. I used about 4 ounces of ground coffee in one batch and another 4 ounces of a different ground coffee in a 2nd batch, splitting the 5 gallons in two. The coffee flavor and aroma was very prevalent in the final product. If you don’t like your coffee strong, you may want to dial back the amount of ground coffee used when doing this method.