As a site dedicated to beer and coffee, what better subject to discuss than how to add a little jolt of caffeine to your next homebrew. While there are many different methods to add coffee or coffee flavors to beer, here are my recommendations for your next brew day.
Ground vs. Liquid
While you may be tempted to add the coffee as a bean or even ground, trust me from experience that adding ground coffee to a beer ends in a nearly impossible to strain mess in your beer, similar to trying to make coffee without a filter. I would not recommend it.
My recommendations for adding coffee are to use espresso or cold brew. Normal warm-brewed coffee can be added, but in my opinion it tends to add an astringency and bitterness that is not pleasant. Espresso and cold brew tend to create a smoother coffee flavor, assuming that both the espresso and cold brew are properly extracted (i.e. not over or under extracted). The additional added benefit of adding liquid coffee is that you can taste what you are adding to determine if it’s overly bitter or sour.
How Much Coffee to Add
This is going to be very dependent on the beer style and how much coffee flavor that you are looking for, but for a typical coffee stout I would start with the equivalent of one coffee drink equivalent per 1 gallon of beer. For espresso this is one shot, and for cold brew this is 1 cup. For a strong cold brew concentrate, I would halve this or even divide by a third as a starting point.
The key, more than the ratio, is that adding the liquid coffee allows you to taste the beer (even un-carbonated) as you are adding it. That brings up the next question of when to add the coffee.
When to Add the Coffee
While some brewers are proponents of adding the coffee during the boil, I don’t suggest this as there is a high likelihood of developing bitter off-flavors from over extraction of the coffee. Considering that the fermentation process has little effect on the coffee, I would suggest adding it either at secondary, or for those who forego secondary, during bottling.
What Type of Coffee to Use?
For a typical “coffee” flavor, I would use a medium roast Central or South American. This will give you a nice balanced cup without excessive bitterness or acidity, which could be unpleasant in a beer. I would avoid African coffees or extremely light roasts due to the high acidity. For those that are familiar with home roasting, Full City would be the sweet spot roast level.
What Type of Beer to Brew?
The obvious choice for beer is a stout, but there are other styles that work great with coffee, including:
- Brown Ale
- Belgian Tripel
- Belgian Quadruppel
- Cream Ales
- Strong Ales
I’ve even had a Kolsch with coffee, which worked surprisingly well, so feel free to experiment! The nice thing about adding at bottling time is that you can always experiment with a few bottles instead of the whole batch. I would suggest taking a 5 gallon stout recipe and experimenting with a variety of additions, including coffee, chocolate, vanilla, raspberries in the same brew to understand the impact of the secondary additions (or bottling additions).
Please feel free to comment with any recipes or suggestions that you may have. Happy Brewing!