Monday, March 28, 2016

What's the Best Way to Add Coffee Into Beer?

It's always fun to think about how many people have, in their combined efforts, produced a staggering number of variations on beer throughout history. Brewers will commonly remark that few things we make today are truly original ideas — that some historic brewer, somewhere along the way, has already tried just about everything. But there must be at least a few inventions unique to modern brewers. We throw some weird stuff into beer. Coffee, one of the more common and less weird things thrown into beer of late, is a pretty obvious and logical adjunct. Not only does it compliment flavors already present in certain beers, but most of us brewers drink just about as much coffee as we do beer. The notion of throwing coffee into a beer seems like something very particular to our modern sensibilities, but who knows? I've never heard anything indicating that coffee was ever used as a flavoring in beer before the 80's/90's, but while it certainly wasn't traditional, it's not impossible that someone tried it hundreds of years ago.

Now, of course, coffee beer is all the rage. (I could swear I recently saw some statistic about coffee beers being one of the largest categories of beer in competitions, but now that it would be useful, I can't find it). There's hardly a style of beer that we haven't tried adding coffee to. Dark beers hardly warrant mention, but I've also seen coffee sours and coffee saisons. Coffee IPAs are not totally uncommon, and at Kent Falls, we took that trend a step further and add coffee to our Brett IPA — which, as far as I know, is possibly the only beer of its kind. 

When we first started producing Waymaker (the aforementioned Brett IPA), we realized we were limited in what we could brew in those first few months by the esoteric yeast cultures I had chosen for our house strains. We wanted to get as much diversity as possible out of a few beers with similar foundations, and easy-to-add ingredients that could spin a new beer off from an existing base was a common sense way to accomplish that. Thus, Waymaker Brett IPA, with the addition of coffee, could become a second, distinct beer: Coffeemaker Brett IPA. Obviously, we were only going to pursue the concept if it worked. And in this case, it worked wonderfully. We partnered with Irving Farm Coffee Roasters — not only one of the best coffee roasters in the region, but one whose roasting facility happens to be a short (only 40 minutes, about as close as anything gets around here) drive from our farm. Together, we tested out a number of roasts and ratios until we had a combination of beer and coffee that we enjoyed for its complexities and uniqueness. 

Since we were doing only small runs of Coffeemaker to start out, figuring out how to actually add the coffee into the beer wasn't hard. The knowledgeable folks at Irving Farm recommended adding the coffee late in the process, and not using cold brew, which wouldn't extract the full range of flavors. We settled on using a 2x coffee concentrate liquid, which could be pumped into the brite tank under CO2 pressure minutes before packaging the resulting blend. No oxygen, just maximally fresh coffee. You could achieve the same effect on a homebrew scale by pouring 2x strength coffee (at an 11% ratio) directly into the keg. 

This method works great when you're splitting off a batch and only turning a small fraction of it into a coffee beer. (It also works great when you don't have to concern yourself with making 15-30 gallons of coffee yourself). We could have easily employed this method with 6 bbl, up to about 12 bbl volumes of beer. But then we started talking about brewing full-sized batches of Coffeemaker, on its own. Potentially up to 30, even 35 bbls. That's a hell of a lot more coffee. That's a volume of beer that would require potentially 80+ gallons of coffee. Can you imagine 80 gallons of coffee? That's an insane amount. That's almost four times what I drink during the average day. How do you make that much coffee? 

We spent about a month brainstorming methods for brewing 80 gallons of coffee. Irving Farm offered us an old giant coffee maker that could brew 6 gallons of coffee at a time, which is a lot when you're thinking of coffee in terms of just drinking it, but bizarrely undersized in terms of a beer that can suck up a bathtub's worth of the stuff. 

Then we took a trip out to San Diego for Modern Times' Festival of Funk. Modern Times established themselves early on as a leader in the coffee beer game by becoming the first brewery in the country to have an in-house roaster. After that, they started barrel-aging coffee beans, not only to sell to the public to drink (I've bought a few bags; they're trippy cool and tasty) but to add back to beer, and complete some kind of insane beer-barrel-coffee Ouroboros loop. Unsurprisingly, while hanging out at Modern Times, we gleaned a few useful methods from their extensive coffee-related shenanigans.

Many brewers add coffee beans directly into their beer, but we'd theorized that it would be best to avoid this method for a few reasons. First, we didn't want to add the coffee too early in the process, before fermentation. Fermentation transforms things, and both the Irving Farm folks and us Kent Falls folks felt that we would get the clearest, most stable coffee flavor the later in the process the coffee went in. Right into the brite immediately before packaging is about as late as you can get, but the volume of liquid then becomes the issue. So why not just add coffee beans into the brite tank or fermentor, in a bag, you may be thinking? Certainly, that could work, and is probably an alternate solution. But there's a degree of control you may have to give up with this approach, as the amount of contact time between the beans and the coffee are now dictated by the time it takes you to package the beer. Plus, we had been worried about the alcohol pulling undesirable flavor compounds out of the beans, especially with that extended contact time. And then there's the simple matter of scale, once more: when you're Modern Times size (much bigger than Kent Falls, and Kent Falls isn't even that small in the grand scheme of things), how many pounds of Stuff do you want to be shoving into your gigantic tanks? If you reach the point where you're brewing a 200+ bbl batch of coffee stout, say, do you really want to be dropping several hundred pounds of coffee beans into your tanks? What are you going to put all that coffee in? How are you going to keep it out of the packaged product? How are you going to fish it back out?

Modern Times had figured out a nice sort of hybrid approach. I've now adapted it here at Kent Falls, and utilized it for one of our most recent beers, a Coffee Milk Stout. This was indeed the first batch of coffee beer that was all what it was — a full-tank, full-volume batch, thus requiring quite a bit of coffee. (Ultimately, I did end up filling some bourbon barrels with the stout before adding the coffee, so the final ratio was a 23 bbl batch of beer that got about 23 lbs worth of Ethiopian Yirgacheffe coffee). Rather than adding the coffee beans into any of the tanks, I thoroughly cleaned one of our half-barrel yeast brinks, which have butterfly valves on the bottom and top for yeast collection. I poured the whole beans into the keg and set up a loop from the bottom of the fermentor (after clearing it of trub), into our cellar pump, into the coffee-keg, out of the top, then through a hose and back into the racking arm of the fermentor. On the out of the keg containing the coffee, I attached our hop filter, which is basically a torpedo-like tube with two inner stainless steel mesh filters, and which in this case would prevent any coffee beans from riding the beer wave out of their holding vessel. (A smaller type of mesh screen that fits inline would work as well, probably better, as this set-up made for an awkwardly vertical hose arrangement). With this loop, the beer gets pulled out of the tank, runs through the coffee, and returns to the tank, cycling a constant mixture of coffee-beer through the vessel(s). I let this cycle run for a little under a day. When the beer was ready to transfer into the brite tank, I simply reconfigured the hoses so that all the beer from the fermentor would pass through the coffee keg once more along the way.

You could replicate this approach on a homebrew scale quite easily, either with my trusty ol' dry-hop keg set-up, or using a simple bag to contain and filter the coffee before transferring. You wouldn't be running a cycle/loop, but the basic idea would be the same.

Either method — coffee liquid, or calculated contact time over whole beans — could be the easier for you depending on your set-up and scale, at least assuming you're a homebrewer or smaller-scale commercial brewer. Above 20 bbls or so, you probably have no choice but to add beans right into the beer. Result-wise, there are also pros and cons either way. I liked how "present" the coffee character remained, even over time, with the direct liquid injection method. The immediacy and purity of the coffee addition seemed to bring about the clearest, most stable coffee character. But with certain roasts, we also noticed that the coffee character would shift over time and develop an interesting note often described as "jalapeno." The flavor never disagreed with me, and I found it more of a subtle shading with a curious flavor association, but it did shift the profile away from pure coffee, even if the beer as a whole remained pretty vibrantly coffee-forward. With the loop method, based on my impressions so far, I think the result will be a smoother but mellower coffee flavor, and I'm curious to see how it holds up over time.

My favorite part of making coffee beers? With all the experimentation and blends and testing and friends made in the coffee industry, you somehow or another end up with a lot of coffee on hand. I remember the days, years ago, when I couldn't even drink coffee after 4 pm without dooming myself to lay awake in bed all night. Haha. Oh man. How young and much healthier I was back then.


  1. 1) Do you have any pictures of your coffee hyper loop? I have an idea of what it looks like in my mind but I'd be interested to see what it actually looks like.

    2) You're spot on about barrel aged coffee beans. Had some bourbon barrel-aged beans from a Denver roaster a couple years ago and they were intense and far different than any coffee I had before. Had to cut them w/ actual coffee beans.

  2. Pretty similar to what I do. I use the bag in keg method. The only difference is that I don't transfer the beer to a new keg. I pull the bag after its ready and then carbonate it. I've found I get better flavor by cold extracting and by using lighter roast. I think the lighter roast contributes less astringency and the cold extraction aids in long term stability.

  3. Interesting approach. I do worry however about a few things with this method, firstly the sheer force you are placing on the beer as it recirculates through a pump continuously for ~24 hours, I also wonder about picking up dissolved oxygen in this process. Have you tested DO in the beer before and after recirculating beer through the coffee? Lastly you said you have a concern about alcohol extracting undesirable compounds in the coffee, keeping your beer in contact with the coffee for 24 hours will still yield these issues, no?

    I too love coffee beer. I have put hundreds of hours working on and developing methods for adding coffee to beer. Each person finds ways that work best for them and their beer, and for us I have found that adding coarsely ground coffee into a fermenter after it has gone terminal, been chilled for 3-5 days and yeast has been entirely drained from the tank is best. I will add the coffee directly into the tank through a dry hop port and then hook up a pump and recirculate from the rack in arm through the bottom of the cone for 20-30 minutes. I then let the coffee cold brew at 32F for 3 days, and then filter the beer o the brite. I have noticed that brewing coarsely ground while the tank is on full chill helps eliminate some of those undesirable characteristics of alcohol extraction. No vegetal, peppery, tannic characters. We closely monitor DO levels throughout process too.

    Your approach sounds interesting and also sounds like you would have a better yield, that is one thing that sucks about adding to the tank directly; we see significant loss in volume due to coffee grounds. But we do the best we can with a DE filter. Thanks for sharing. I hope I get an opportunity to try some of your beers. Brett coffee IPA?!? Sounds so crazy it could work!

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  5. Nice article.
    I have brewed a coffee ipa recently and I have used coffee beans in the fermentor (about 60 gram for 10 liter for a1.5 days) it came out really good and I certently will do it again. I also get jalapinio aroma from my beer but I think it's because of the coffee roast I have used.

  6. Insightful post! I don't particularly enjoy the "jalapeno" flavor as I believe it detracts from the coffee and beer flavors. Have you noticed any patterns to which roasts tend to give this character and which ones don't? Thanks!

  7. With a brew length of only 5 gallons I'm inclined to simply add half a gallon of freshly brewed double strength coffee. My concern is: how much oxygen is there in freshly brewed coffee?

  8. This was the first beer I had of yours, loved it. Excited to see your stuff landing down here in the boroughs of NYC, as I've been reading your blog for years and glad to see you having success with this.


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