I haven’t written in a while so there’s some catching up to do.
The last post had to do with finishing fermenting the Belgian Golden Strong and reusing the yeast on a Belgian Dark Strong. That went over perfectly. I ended up just siphoning the Golden out of the fermenter so there was about 3/4 of a gallon of yeast/beer slurry at the bottom. Then I shook it around real good to mix it all.
I then brewed the belgian dark strong which I think went perfectly, though it’s hard to remember since it has been so long. When I was done brewing I poured a few cups of the yeast slurry from the previous batch right into my new beer. The fermentation took off within a few hours and finished beautifully. I fermented the belgian dark pretty cool, at 67 degrees or so. Belgian yeast can withstand much higher fermentation temperatures but I wanted this to be crisp and clean. Higher temps lead to an abundance of fruity characters in the beer.
2 weeks later I had a belgian dark strong. I was really looking forward to having it ready in time for Heather and Jon’s wedding. Well it was finished fermenting.. but not ready.
Both of my belgian strong ales have a problem. They seem to have a fantastic aroma and flavor, but there is a higher-alcohol bite that is WAY to strong. The golden I can understand because the recipe wasn’t exact and I went too heavy on the belgian candy sugar. The recipe for the dark was right on though. But I think I know why this happened and can easily adjust in the future. Here’s the deal.. it has to do with mash efficiency.
Mash Efficiency:
Beer is measured in points of gravity, or the amount of sugar suspended in a liquid. I don’t have my numbers in front of me but lets assume my belgian dark strong, before fermentation (ie. when I got done boiling) had a gravity of 1.080. Water is 1.000, so you can say this beer has 80 points of sugar more than water (which has none).
Now, where does this sugar come from? The grain mostly. Grain is loaded with starches. Luckily, grain also contains enzymes that, when brought to a specific temperature, begin to break big starches into smaller starches (sugars). Let’s say a particular type of grain has the potential to give X gravity points per pound. When I mash the grain (or apply hot water to it for an hour, mixing periodically) the enzymes should extract all that potential sugar into a nice sticky syrup that I use to make beer. The problem is, it never gets 100% of the sugar. What’s most common is you will get around 75% of the potential sugar out of the grain. That number, 75%, is your brewhouse efficiency and everyone’s is different. It depends on your brewing system, your procedure, the grain, how fine or course the grain is milled. I’m pretty sure on my system I can expect to get around 70% extraction rate.
Now here’s the problem. I have a recipe that relies on 95% of my sugar to come from grain, and 5% to come from actual sugar cubes. But that’s assuming I get 75% extraction from the grain. If I only get 70% extraction, I have less sugar from the grain than I thought. Now that may throw my percentages off and all of a sudden 90% of my sugar is from grain and 10% is from sugar cubes. The problem in that is sugar cubes are 100% fermentable, meaning yeast will completely consume that and shit it out as alcohol and CO2. Sugar from grain is not 100% fermentable. There are some sugars that are too large for yeast to eat, or they don’t like, and that leads to a residual sweetness in beer. It’s a sugar that you can taste, but yeast won’t eat into alcohol and CO2. So by having a low brewhouse efficiency, I’ve increased the percentage of sugar cubes, meaning I now have a beer that is just as alcoholic as it would be, but doesn’t have that sweet malty backbone to balance it out. It’s just overwhelmingly alcoholic. That’s my belgian golden and dark strong ales.
I can do two things now. I can let them age for a long time and hope over time things mellow out. Or I can brew a small amount of a sweeter beer and blend with these two. I’m opting for the former since I have some extra kegs. The dark and golden are sitting in a corner of my basement as we speak. They’re going to sit sealed up in kegs for at least 6 months before I try them again. Oh well…
Now the dunkelweizen… damn this brew pissed me off.
So I started off searching for recipes. It was very hard to find dunkelweizen recipes for some reason. Dunkelweizen’s are dark wheat beers. True you don’t see too many in the market but I’ve had a terrific one at a local german restaurant and really wanted to try my hand at it. So I eventually found on thebrewingnetwork.com’s forums a listener who posted his recipe for a dunkelroggenweizen, or a dark german rye and wheat beer. The recipe was very simple — some pilsner malt, wheat malt, a lil rye, and some dark grains for flavoring and color. I removed the rye from the recipe and replaced it with pilsner malt. Perfectly simple and understandable. Alex recently had great luck with a hefeweizen recipe that was very similar (minus the dark grains) so I was confident that the recipe was a good one.
So… I started by mashing the beer at 154 degrees for an hour and batch sparging and ended up with a brewhouse efficiency of like 34%. Yep that’s thirty four percent. Not 70% like I should have. So I basically extract only half the sugar I need from the grain. There are several things I could have done to resolve this. 1.) Bring the sugary water that I extracted up to about 160 degrees and pour it all back into my grain mash to try and extract more sugar. 2.) Do the same thing as 1, except take about 1/3 of the grain out and boil it first (called doing a decoction mash), then add it back in. This has the effect of warming up the grain, breaking some more starches down, and darkening the beer. Or 3.) Take what I have, 7 gallons of semi-sweet water and boil the living shit out of it until it’s a much more concentrated solution. I did 3 because I’m dumb and didn’t think of 1 and 2 at the time. In fact I had even planned on doing a decoction mash anyway and forgot.. grrrr. So I boiled my 7 gallons down to about 3.25 before it reached the proper sugar concentration (gravity points). This was a recipe for 5.5 gallons of beer, but I boiled off so much of the water I was at 3.25 instead.
The second problem was the yeast I bought. I picked up 2 vials of yeast for this batch. When I got home I realized they both expire in 11 days. Yeast has a 4 month shelf life and during that time their health drops out fast. 11 days before expiration leaves me with about 18% of the vial being actual healthy yeast. So I had 1/5 of the amount of yeast I actually needed. To compensate I had to make an entire gallon yeast starter (actually two half gallons, one vial of yeast into each).
So after the brew was done I now had 3.25 gallons of beer, and 1 gallon worth of yeast to dump into it. If I were smart, I would have said to myself “well shit, since I have only 3.25 gallons of beer, not 5.5, I should only put 1/2 of the yeast in there and save the other half gallon for something else.. like brew a second batch of this tomorrow to try and fix the mistakes”. But no, again I wasn’t thinking so I dumped the entire gallon of yeast in there. So now 1/4 of my beer is yeast. Needless to say the fermentation took off in like 3 hours. I woke up the next day to find the beer bubbling over the aluminum foil airlock I had made and onto the floor. This sucker is active! I plan on taking a test of it Saturday to see if it’s done. I can’t imagine it’s going to taste very good at all.
So to compensate for the shitty judgment on my part I set out, with inspiration from Alex who is doing the same, to come up with a brewing spreadsheet that will meet my needs. I want something that will help me formulate recipes, adjust them when I need to, help me determine my water amounts and temperatures, etc. And I’m almost there actually.. it’s coming along well though I’ve literally put like 24 hours into working on it. I’ve had to relearn algebra to do it which has been fun. With a little coaxing and sanity checking from Chris Clark, I/we were able to take this formula for determining how much boiling water you need to bring your grain from one temperature to another: Wa = (T2 - T1)(0.2Ga + Wm) / (Tw - T2), and convert it the opposite way to tell you if you had grain at one temp and added a certain amount of boiling water, how hot would it make your grain: T2 = (T1(.2Ga) + T1Wm + WaTw) / (.2Ga+Wm+Wa). I have to say, I never gave .2 shits about algebra in school and promptly forgot all the rules and I’m kicking myself now. I really really needed to convert that formula and it took a lot of research in wikipedia, purplemath.com (a good site for algebra tutorials), and some help from Chris for me to remember how to do it. Now I can do it in my sleep and already converted it again to Tw = ((T2 - T1)(0.2Ga + Wm) + WaT2) / Wa to tell me how hot to make my water if I want to add a certain amount to grain at one temperature to bring it to a higher very specific temperature. And it works perfectly! Yay.
OK enough for now, time for work…