Monday, March 18, 2013

Brew day: Altostratus Franconian Dunkel and High Pressure Honey Bock

Okay, finally catching up on my brew days... When I last took chisel to stone tablet, I was writing about my partigyle brew day where I ended up with three stouts. Before that, I had done a split batch where I steeped grains in the one kettle to yield both a light beer and a dark beer out of the same mash. While the brew day is now over two months old (Jan. 13th is when we brewed), today I'm going to look at a third approach for getting multiple beers out of one brew day: what I call quasigyle.

So, partigyle is where you collect the first and second runnings into two kettles, giving yourself a big beer (in my case an imperial stout) and a small beer (an oatmeal stout). Here I was thinking of getting both a Dunkel and a Bock out of a single mash, but the difference in gravity isn't as great as a partigyle. So my thought was to do what I've decided to call a quasigyle: collect the first gallon separately, then collect the rest as normal. Then once you have the gravity measured for both, you can decide how to split them up so that you hit your desired gravities. In my case, my initial recipe had a predicted gravity of 1056 and I was planning on a Dunkel around 1052 and a Bock around 1061. I was also planning on adding a pound and a half of honey to the secondary to bump it up to 1069.

So how did it work out? Pretty well, overall. I did a double decoction, and... okay, so not everything went well. I figured out at the end of the day that my probe thermometer may have been off by as much as ten degrees, so to be honest I'm not sure what temperatures my decoction was at at any given time, but the idea was to mash in at 131°F, decoct to 158°F (allowing the decoction to rest at 148°F) and then decoct again to 168°F for mash-out. Who knows what really happened.

That being said, my quasigyle idea seemed to be a winner. My first gallon was at 1080. Due to poor record-keeping combined with my inability to get the right amount into each kettle, I'm not sure exactly how much wort I ended up with in each kettle. What I do know is that I collected roughly 11 gallons of wort overall, and the kettle that started with five gallons of the wort plus the gallon of first runnings (my honey Bock kettle) had a mixed pre-boil gravity of 1060. Doing some back-of-the-envelope calculations, I would estimate that my other kettle (the Dunkel)--and thus my total runnings after the first gallon, was at 1056 pre-boil. Since I was a little low on my volume for the Dunkel for some reason, I actually diluted with more water during the boil to keep it right around 1056. The Bock ended up at 1064. I chilled to around 60°F, let it chill further overnight, and aerated and pitched the next morning around 45°F. I let it rise to around 52°F.

I added the honey to the Bock after primary fermentation was done. The Bock is still lagering; the Dunkel is on tap. Unfortunately, I'm thinking that the thermometer malfunction messed up my mash and the Dunkel ended up somewhat underattenuated (final gravity around 1020), though the aggressive hopping plus the higher-than-expected starting gravity actually made it turn out like a pretty decent Bockbier. I hope to keg the Honey Bock soon.

So there you have it... my quasigyle method. I'm actually thinking of employing it again sometime in the next month when I want to brew both a Maibock and a Helles from a single mash, with 20% rye for kicks. Hopefully that works out just as well--though with new, functioning thermometers.