Eureka, this is another pilot brew project from 2010. I did a Irish Stout recipe in small-scale and used a share of it to make a Coffee Stout. Coffee is another passion of mine. Luckily for me, Switzerland has a great coffee tradition and a lot of local coffee roasters with many different kinds of coffees. So why not get beer and coffee together for once? I have to mention this is not a new idea. Several commercial breweries produce some fantastic coffee beers already. The recipe below is basically the same as the Irish Stout base recipe. Lets go through the recipe:
|Numbers:||Volume [L]||5 (1.3 gal)|
|Color||Around 105 EBC (measured 98)|
|Grains:||Pale malt (6.5 EBC)||0.675 kg|
|Caramunich 3 (150 EBC)||0.03 kg|
|Barley flakes||0.15 kg|
|Oatmeal flakes||0.06 kg|
|Roasted barley (1150 EBC)||0.085 kg|
|Acidified malt (4.5 EBC)||0.1 kg|
|Hops:||Target (11.5% AA)||4 g and boil for 90 min|
|East Kent Goldings (6.5% AA)||2.7 g and boil for 90 min|
|Yeast:||Wyeast’s||#1084 Irish Ale|
|Water:||Burgdorf||Mash: 3 L (0.8 gal), sparge: 5 L (1.3 gal) @78°C (172°F)|
|Rest:||Mash in @66°C (151°F), 90 min @45°C (151°F), 10 min @ 78°C (172°F)|
|Boil:||Total 90 min|
|Fermentation:||Primary||5 days @20°C (68°F) in plastic fermenter|
|Maturation:||Carbonation (CO2 vol)||2|
|Maturation time||4 weeks|
August 2010: Brew day. The procedure of the Irish Stout can be found here. At the end I bottled 0.8 L of the Irish Stout with 0.2 L of coffee (Espresso). I used 10 g of an Espresso coffee and let it steep for some time in 0.2 L of hot water (not boiling) and blended it with the beer after it cooled down. This gives a coffee to beer ratio of about 10 g for 1 L (or 1.3 oz to 1 gal). For the carbonation, I added 10% of unfermented wort to get to a carbonation level of approximately 2 vol. I then left the bottle carbonate for a week at ambient temperatures and let it mature for another three weeks.
October 2010, tasting of the coffee stout.
Aroma: Lots and lots of coffee character. Nothing else. The coffee kind of overpowers the humble Irish Stout base. Although the aroma is right up my alley, I would choose another coffee with more character next time.
Appearance: Black with a nice frothy tan-colored head. Could observe some drops of grease at the surface of the beer. The head vanishes rather quickly.
Flavor: Lots of coffee again. This beer is more bitter than the clean Irish Stout without the coffee. All the other flavors of the Irish Stout get displaced by the coffee flavor. Very similar to a cold coffee.
Mouthfeel: Medium body, lively carbonation, medium lasting sweet aftertaste. No bitter aftertaste.
Overall Impression: Too much coffee character! The coffee just displaces all the flavors and aromas of the Irish Stout base beer. Either decrease the amount of coffee, use a different variety or add it to a different kind of beer. A Russian Imperial Stout could work very well with some coffee. Although, my last Russian Imperial Stout had a lot of coffee character already without the addition of coffee. In addition, consider a technique to get rid of the oils from the coffee to prevent the greasy surface of the finished beer… It looks rather unpleasant.
Did some research in the meantime concerning coffee and beer. It seems there are several different approaches to get your coffee into the beer. One way is to steep the beans in the cooling wort, another one is to soak the beans in cold liquid, add the beans during the boil, yet another one is to add the beans into the secondary fermenter, add them five minutes before sparging… The list goes on. Not to mention several different sources about how much to add. As with many other techniques, there is no right or wrong one to do it as it seems.
I just had a coffee roasted over a coal fire with a very distinct smokiness. A smokiness I have never encountered in a beer before. Another experiment is on the horizon. I will try the cold steeping method and add the coffee to the bottling bucket and add some steeped beans to the secondary fermenter. Maybe filter the cold steeped coffee twice to get rid of the oils. I already see myself throwing some beans in the secondary fermenter and not worrying about the oils and a possibly destroyed head of the beer. Stay tuned!