A most excellent brew day experience! – Covenantal Coffee Ale

Exterior shot of Alaskan Brewing Co., taken by Yours Truly back in July, 2008

I’ve mentioned several times on this blog that I’ve been working on a recipe for a coffee-infused brown ale. It’s a dream I’ve had for 4 or so years now; ever since I had a coffee brown ale in Juneau, Alaska at the Alaskan Brewing Company back in July of 2008. They have a tap at their brewhouse that is dedicated to experimental or employee-originated brews. Brews found on this tap will likely never make it into the wild, and the coffee brown I had there was one of those. I thought it sad that they would never release it, as it was easily the best coffee beer I’d ever had. I determined then that I would develop a recipe that was at least a close approximation of that coffee brown, and I am finally getting to the point where I can begin brewing this recipe. This last brew day was a fantastic experience, and I’d love to share it with you, my congregation.

I mentioned before that I am implementing several changes in my home brewery, which I have taken to calling Amadan Brews. “Amadan” means “fool” in Scottish Gaelic, and it’s the first Gaelic word I ever learned. These changes are in response to several brews that did not meet target numbers in terms of the amount of fermentable sugars I’m getting from my grain. Essentially not getting a decent amount of extraction efficiency from the grain means I’m wasting money (and grain). I sought advice about remedying the situation, and I think I’ve found several solutions that work for me. Rather than create a narrative as to how my brew day went, I’ll describe each piece of equipment and how it contributed to the overall effectiveness of my home brewery. I love this new stuff, and am looking forward to how this beer is going to taste!

Refractometer – There are 2 ways most homebrewers measure the amount of sugar they’re getting in their beer. The one most people start with is the hydrometer. This measures the amount of sugars in suspension by comparing the buoyancy of a fixed weight to how buoyant that same weight is in regular water. This is called specific gravity. Water is a 1, and pre-fermented beer is higher than that. I was shooting for 1.059, and ended up at 1.062. The way you check gravity with a hydrometer is to take a sample of liquid, cool the liquid to as close to 60 degrees as possible, measure the temperature, float the hydrometer in it, spin to dislodge any bubbles, take a reading, compensate for any temperature above or below 60 degrees, and there’s your gravity. Yeah…it’s annoying and frustrating. Add to that the fact that my samples always seemed to have bubbles on top of them, obscuring my read of the hydrometer, and you have a situation where I’m equally as likely to toss the hydrometer at something hard in frustration as I am to actually take a gravity read. I needed to do something about this if I was to get a handle on my efficiency issues.

The something that I did was to spend the $40 on a refractometer. A refractometer, much like its name would imply, reads the amount of sugars dissolved in water by measuring the refraction of light passing through a thin layer of liquid and a prism. It takes its measurement in brix, which is the amount of sucrose dissolved in water, but plenty of tools are available to convert this value to specific gravity. I use the Brewzor brewing calculator tool available for Android devices, but there are plenty of sites that will do the same calculations on a PC or smartphone. The only “gotcha” with the refractometer is that it does not read alcohol. So you have to perform a different calculation if you’re measuring final gravity, but honestly, it’s a tiny gotcha. The gains made from being able to do QUICK measurements easily outpace the inconvenience of having to do a quick calculation. What’s more, there are slightly more expensive models of the refractometer that have a dual scale, brix and specific gravity. The basic operation of a refractometer is very, very simple. Take the included eyedropper, and pull up a little bit of your wort. Shake it to get the bubbles to the top of the dropper, and drop 2 drops on the refractometer prism. My refractometer has an automatic temperature compensation so that the ambient temperature won’t affect the reading much, and the 2 drops of liquid I pull from my wort will immediately adjust to the temperature of the prism. No waiting, and no need to pull more of a sample than the 2 drops. You couldn’t ask for a better way to read gravity.

How I used it: With the refractometer, I was able to take quick readings when I was doing my yeast starter. I misread the instructions, and I didn’t use enough water, so the resulting starter wort was something like 1.12, when it should have been 1.05. I took a quick read while the wort was cooling, quickly boiled water in the electric kettle, and started adding it bit by bit, taking gravity readings after each addition. I probably took 4 or 5 readings within a few minutes, which worked PERFECTLY. I highly recommend the refractometer instead of the PITA hydrometer.


The Rebel Grain Mill

Grain Crusher– A strong contender for the “Biggest Cause To A.E.’s Efficiency Issues” trophy was the crush on my grain. I talked about the mill in a different post, so I’ll keep this mostly short, but basically, I was buying my grain from a homebrew shop, and was having them crush it for me. They used their in-store mill, and since I’d always bought my grain from them, I really had no reason to doubt their crush. However, when I got 52% extraction from my last batch, I started to wonder about it. You see, the barley used by homebrewers must be crushed so the enzymes which convert starch to fermentable sugar can have at the starches locked within. A poor crush means less starch will be accessible to the enzymes, if the crush is too coarse. A crush that is too fine can lead to stuck lauters, where we can’t get the liquid out of the grain bed because of too much fine particulate matter clogging up whatever false bottom is used.


The Rebel Mill on a 5 gallon bucket. Preparing to grind the grain into the bucket. The base fits the bucket perfectly!

So when I had targeted the crush as a potential problem, I had to decide how to take care of it. Having someone else crush my grain was one possibility. Buying a mill and crushing my own was another, and the solution I decided to go with. The mill pictured in this post is a monster of a mill, designed by homebrewers to provide the best crush possible, and it does a stellar job. It’s mostly stainless, with the side plates being made of aircraft grade aluminum, and the rollers being made from tool steel. The base is made from precisely milled wood, and is designed to fit perfectly on a 5 gallon bucket, while the rollers are designed to hook right up to a drill for easy access to power. The drill I used was underpowered and the RPM’s were way too high, but it worked.


The awesome crush I got off the Rebel Mill. I couldn't be more pleased.

How I Used It: The beauty of crushing your own grain means you can buy your grain in bulk, which is precisely what I did. A 50-lb bag of grain cost me $35, while buying the same amount of grain piecemeal would have cost me a total of $70. The savings is immediate. Getting a good crush means I can use less grain for each batch, saving me there, and it also means I can have a good handle on the efficiency I can expect from my home brewery. 75% is what I estimated, which is a darn sight better than my 52%, so I am better able to plan my recipes. A fantastic way to get a 10%-20% increase in efficiency, and I HIGHLY recommend the Rebel Brewer mill if you’re in the market. Rebel Brewer


My home-built 3-tier brewing system.

False Bottom and Rotating Sparge Arm – The final piece of the extraction efficiency puzzle was my sparging technique. Sparge is a funny old word used in brewing and it basically means “rinse”. It’s more than that, of course, but whenever possible, let’s keep it simple. Once you have mashed to convert the starches in the grain into fermentable sugars, it is now time to rinse those precious sugars into your boil kettle. There are a couple ways to do this, but the most effective at increasing efficiency is “fly sparging” or “continuous sparging”, which is when you slowly, and continuously rinse the grain from top to bottom. Pictured is my home-built, jerry-rigged 3-tier system. At the top right is my hot liquor tank which provides the hot water for the sparge, the middle is the mash tun with my new rotating sparge arm, and the bottom-left is the boil tank which is where the sparge water drains.


The rotating sparge arm turning and rising my grain with hot water.

The sparge arm is simply a contraption which provides a nice, gentle sprinkling across the grain. It’s a small, perforated metal tube, connected to a length of tubing, which rotates when water is put through it. The sparge arm is connected to my hot liquor tun, which is what provides the hot water. This provides an even distribution of water across the top of the grain, which helps to provide an even rinse of the grain throughout the grain bed. The false bottom is a domed screen which attaches to the spigot of my mash tun and helps keep the grain from going into the boil kettle, but also provides an even distribution of drainage across the entire bottom of the mash tun. Some people wrote that the “rotating” sparge arm ceased its rotation after awhile, but I really didn’t have a problem with it. We’ll see how it works after I clean it, etc. but I was really pleased with how well it rotated. I was able to get the arm a couple inches from the top of the grain bed, and the equipment worked exactly as advertised!


The false bottom of my mash tun, connected to the external spigot.

How I used it: This one is simpler to explain. I used to use a process called batch sparging, where the sparge water is put into the mash tun, let sit for 15 minutes, and then drained off. It’s a less labor intensive process, and many brewers get great efficiency from this method. With my efficiency being as low as it was, I needed every bit of help with my process, so I decided to move to fly sparging. Commercial breweries, who are more concerned about efficiency than homebrewers all fly sparge. This is because a couple points low on their scale can translate into hundreds of pounds of extra grain. My thought was that by changing my process, I would be able to extract the sugars better using the same process they use. I didn’t find it all that much more cumbersome, so I will likely continue to do it.

So there you have it. A summary of the new equipment and how it helped to increase my extraction efficiency. As always, we had a blast, and I am looking forward to doing it again. The brewing process may seem a little labor intensive. I’ve been asked a couple times, “You know you can just buy this stuff in stores, right?” Yeah, there’s plenty of stuff you can buy in stores. There is something about pulling a glass of beer from the tap in your refrigerator and knowing that it’s YOUR beer. Not much really compares to that, you know? When you give it to someone and they are impressed that you made it, that’s a good feeling. It’s hard to beat. And as I’ve said before, if you start brewing, it’ll add more to your ability to appreciate quality beer than anything else you can do. For that reason alone, it’s worth it to me.

2 thoughts on “A most excellent brew day experience! – Covenantal Coffee Ale

  1. Pretty spiffy 3-tier system. Where did you get the kegs for them, and did you convert them yourself or did you have somebody else do it? Also, for the mash tun, any specific reason for the round drink cooler over the square cooler, or really just whatever you can get your hands on? I do figure it is easier to fit a false bottom in a round cooler, and it probably saves spaces (horizontally at least).

    • The first keg was one I purchased from the chi company online, and Mark Oliver (father of brewmaster Don Oliver from Dust Bowl Brewing Co.) fabricated it into my keggle. The second one I bought from a dude on Craigslist earlier this year.

      As for the round cooler, I like them better because the smaller the area of the circle, the deeper your grain bed. When making session beers, you’re using significantly less grain, and the shallower the grain bed can mean not as good of a sparge, so I have heard. I don’t know if it means less filtering through the grain bed, so a cloudier lauter, or more bed compaction resulting in a greater likelihood of a stuck lauter, or even that it’s harder to get a good fly sparge if you can’t easily distribute the sparge water over the whole bed?

      In any event, I’ve always used cylindrical, and it’s always worked for me. 🙂

      Thanks for the comment!

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