Brew Day: Hoar Frost Oktoberfest

As the calendar turns to August, I know Oktoberfest is right around the corner. As I mentioned in a previous post, I have two different Oktoberfest parties to brew for, as well as my own Novemberfest party. First on my to-do list was a Märzen, more commonly referred to in the U.S. as an Oktoberfest beer. (Seems appropriate, right?) So Saturday morning I decided to return to the very first lager I ever brewed, only this time it's an all-grain recipe and--for the first time in our relatively brief brewing career--a decoction.

We decided to do a simple, single decoction without a mashout. Fortunately Beersmith has a nice decoction calculator that tells you exactly how much to decoct. Per the calculator's instructions, I started out by mashing in the 24 lb. of grain with 36 qt. of water at 131°F with a target temp of 122°F. Since Beersmith always seems to underestimate the strike temp for my saccharification rests, I went with the Green Bay Rackers calculator, which recommended going three degrees above the Beersmith suggested temp of 128°F. Turns out I should've listened to Beersmith this time, as I ended up mashing in at 128°F instead of 122°F. No biggie, I'm assuming. After mashing in, I pulled 16 qt. of the mash (keeping it on the thick side) and decocted it for fifteen minutes. Since it took fifteen minutes to mash in, fifteen more to get the decoction to boil in the first place, and fifteen minutes to boil the decoction, the rest of the mash ended up having a 45 minute protein rest. The decoction itself didn't seem too difficult; there was a lot of stirring involve to prevent scorching and I had to add 1/4 tsp. acid blend to bring the pH below 5.7, but overall it was easier than I expected. I also added 1/8 tsp. acid blend to the remaining mash to drop its pH as well.

When I added the decoction back to the mash tun, I decided to listen to the Homebrew Digest advice which said don't add all the boiling mash back at once, as you'll probably overshoot your target temp of 155°F. Well, I found it was hard to mix the mash and get a consistent temperature reading at first, so I ended up doing a lot of stirring and adding, stirring and adding (all while the remaining decoction was cooling). Eventually, when I dumped everything in, I ended up between 150°F and 153°F instead of 155°F. Accordingly, I'm thinking the next time I'm just going to dump the whole thing in right away and trust Beersmith's calculation. Worst comes to worst, if I'm significantly high on my temp I'll mix it until it cools down.

Anyway, from mash-in to hitting my saccharification rest temp it only took me an hour, so I don't think my brew day was significantly longer than if I had simply done an infusion mash. After a 45-minute sacch rest, I recirculated for ten minutes and then sparged for 1:15. Due to a very full mash tun (which caused me to mash in a hair below my 1.5 qt./lb. intended ratio) and a slight problem pumping water to my hot liquor tank (a hose popped off) I lost enough sparge water to cost me roughly a gallon in collected wort. I boiled for 6o minutes (I hope that was enough to drive off all the DMS) with hop additions at 60, 45, 30 and 10 minutes. I also added Irish moss at 15 minutes.

The only significant issue I ran into was while cooling. I had some wiring issues with my pump (mainly because I'm an idiot an rely on electrical tape to keep wires together). This, plus issues with my pre-chiller (mainly because I'm an idiot and rely on duct tape to close holes in a copper immersion chiller) and 80°F+ temps meant it took roughly 45 minutes to chill the beer, and even then it was only around 75°F, far above my intended temperature. As a result, I may have shocked the decanted 1-gallon yeast starter onto which I racked. Nonetheless, 24 hours later fermentation had started.

Overall, it was a pretty great brewing day. My O.G. was a tad high (1062, as compared to my target O.G. of 1060) but my yield was also a tad low. The color looked great, and the cooled sample tasted quite smooth as far as the hops were concerned. I'm really curious to see how this turns out, particularly considering that 1.) it was my first decoction and 2.) I used all American malts (Rahr Pilsner and Briess Munich), save a pound of Belgian Caramunich (couldn't get my hands on Weyermann Caramunich, sadly). It was also a pretty efficient brew day, starting a little past 10am and finishing by 3:45pm including a longer than usual chilling time. If all goes well I just might have to decoct more often! Jawohl!