Brew day: Stout-A-Palooza

Having the capacity to brew ten gallons (as opposed to the standard 5-gallon batch) is great. The additional time and resources it takes to brew ten gallons instead of five is minimal, so for an extra hour and twenty dollars (rough estimate) you can end up with an extra keg of beer. The one problem is that, unless I'm brewing for a party or really like a beer, I'd prefer two different styles of beer out of a brew day. I have two kettles and two burners, and the ability to split the wort into two kettles naturally gives me a lot of variables to change between the two beers. 

My first experiment with split batches is what I'll dub the split-and-steep method. Back in the spring, I brewed ten gallons of light mild ale wort and then split the wort into two kettles. The one kettle I finished like normal but in the second keg I steeped some chocolate and Carafa malts for about a twenty minutes to make a dark mild ale.  The results were overall positive, though I suspect I might need to up the amount of steeped malts as compared to what I would normally use when added to the mash.

Two Saturdays ago, I decided to experiment with a more traditional method of split-batches: parti-gyle brewing. I'm no expert, so feel free to correct me in the comments if I get a detail wrong, but my understanding is that this was fairly common in the English brewing tradition, and was also practiced by Trappist brewers. The idea is pretty simple: when you first start collecting wort, it's more concentrated than at the end. So if you collect the first half of your wort (or first third, depending on how high-gravity you want your first beer to be) into a different kettle than the rest, you're left with a strong beer and a small beer. A handful of commercial brewers still practice this: Anchor brews its Small Beer from the second runnings of its Old Foghorn Barleywine, and here in Chicago, Revolution has brewed a parti-gyle version of their Eugene porter, calling the strong beer Hugene and the small beer Weegene. You can also add more specialty grains to the mash when you're done collecting the first runnings to change the character somewhat.

(On a side note, last Sunday I tried a third method that I'll call quasi-gyle; I hope to post about that soon.)

My inspiration for this parti-gyle brew day was an imperial stout competition put on by Goose Island. I've been meaning to brew another batch of my None More Buzzed coffee stout, and when I read about the impy stout competition I figured I could kill two birds with one stone. Eventually I decided to pass on the competition but the idea lingered. I've also been toying with the idea of brewing a mole stout, so I realized I could blend some of the strong beer with some of the small beer to get a third batch of beer. So that's what I did.

Yup, this is brewing in January in Chicago.

The plan was fairly straightforward: simple infusion mash at 148°F; recipe predicted an original gravity of 1069, and this calculator predicted original gravities of 1092 and 1046, respectively, for each gyle. I only ran into one issue: I suspected at some point that my digital probe thermometer was off. By the time I found an analog one, I discovered that my mash had been sitting at around 130°F for 45 minutes. D'oh! I immediately transferred the mash to a kettle and direct-heat raised it to 150°F. (The next week I discovered that the analog thermometer may have been slightly off as well, so God only knows what I actually mashed in at.) I then let it rest for about 45 minutes before recirculating and sparging, collecting roughly 5.5 gallons of each figuring on 4.5 gallons post-boil.

Don't know if the long unintentional protein rest had anything to do with it, but I ended up with really good efficiency. I ended up with 4.25 gallons of imperial stout at 1100 and 5.75 gallons of oatmeal stout at 1056 (not sure how I ended up with the volume differential; I thought I collected the same amount in each kettle). I diluted the impy stout with a half gallon of bottled water to drop it to 1089 (since I was shooting for 1092) and pitched one packet of Nottingham dry yeast in the regular stout and two packets in the impy stout.

The fermentation took off like gangbusters. In fact, as you can see on the right, it made one hell of a mess; I estimate I lost a whole half gallon from the impy stout due to blow-off. Leah racked the impy stout to another carboy and the oatmeal stout to a keg last Sunday. I just checked last Wednesday and after ten days the impy stout was down to 1024 and the regular oatmeal stout was down to 1015. 

Next up I'm going to collect one gallon of the impy stout and two gallons of the oatmeal stout into a keg which will become my Buenas Tardes Amigo mole stout. For that beer, I'm planning on steeping some vanilla beans, cacao nibs, cinnamon sticks and ancho and guajillo in tequila based on the ratios in this Mad Fermentationist post and adding that to the keg to taste. Next, I'll cold-steep whole coffee beans in the rest of the oatmeal stout to make my None More Buzzed coffee stout. Finally, I'm going to soak some vanilla beans in bourbon and add that to the impy stout, which I'm going to bottle condition, to make my Eби Путина vanilla Russian imperial stout (note on the name: according to my friend Shannon--or more specifically, her friend who's fluent in Russian--it's pronounced "Yebi Pootina" (first word-accent on "i", second word-accent on "oo")).

So yeah, I figure I'll get roughly three gallons of coffee stout, three gallons of mole stout and three gallons of vanilla imperial stout out of one brew day. Not bad, eh?

UPDATE (1/20): I currently have two concoctions steeping to add to the mole stout. One is a whole guajillo pepper and half of an ancho pepper (mostly de-seeded) steeping in three ounces of Lunazul reposado tequila. The second is 2 oz. of cacao nibs, two (old, somewhat dried out) vanilla beans and one and a half cinnamon sticks steeping in three ounces of the same tequila.