Time for a Schwarzbier

Time for a Schwarzbier. I've always liked the style and the better ones I've tried are nice drinking lagers. I planned to use the yeast cake from the Oktoberfest, so when that quieted down, I racked it and harvested the yeast. This is the third generation of the yeast and likely the last use of it.

This time, I took some guidance from Nic and made up a spreadsheet to track what I was doing. In retrospect, I think that I got a lot more useful information that using my old format. I still have the time-based notes and they are useful, but the extra detail is nice. That spreadsheet is available here.

There are two problems I picked up on while documenting in this new-and-improved way:

Volume calculations
Although I corrected for the volume difference between ambient, mash temp, and boiling, I seemed to have collected more from the first and second runnings that I actually got in the boil kettle. Because the sparge water is in the boil kettle, I need to put the first runnings into a bottling bucket, sparge, transfer the bottling bucket contents to the boil kettle, sparge again into the bottling bucket, then transfer that into the boil kettle. The bottling bucket isn't perfectly vertical, but I accounted for that. Somewhere in measuring the wort depths and calculating volumes, I introduced some errors.

Efficiency
I read through Brewkaiser's wiki and used his efficiency spreadsheet. While my calculated efficiency comes out areound 77%, the lauter and conversion efficiency numbers were off (well over 100%). I think that decoction threw that off and I just didn't understand the calculations before using the spreadsheet. I'll see what happens next time I brew since that likely won't be a decoction.

Finally, my 24" brewing thermometer was out-of-whack. For some reason, when I was ready to mash, it read about 20F below actual (as measured with my digital and mercury thermometers). I was able to recalibrate with ice water, hot tap water, and boiling water by using the adjusting screw on the back, but I'm surprised that I needed to. I lost about 45 minutes figuring that out and resolving it. From now on, I'll validate the reading before starting to mash. I'll also need to put a flat-headed screwdrived into the brewing toolkit.

Day 0 (25 Sep 2010)
0815 :: Preheat mash tun with 8 gal hot tap h2o.
0840 :: 4.55 gal h2o on full (T = 65F).
0847 :: Mash h2o @ 115F; want to mash in @ 160F.
0851 :: Mash h2o is 138F.
0853 :: Turned burner down to constant flame cf noisy flame - replace rusty burner?
0858 :: Mash h2o is 167F.
0900 :: Mash h2o tempin tun only 148, so reheat the mash h2o to 175F.
0913 :: Mash h2o @ 182F.
0930 :: The dial thermometer was off by about 20F! recalibrated against the digital instant-read at freezing, boiling, and hot-tap. back on process now.
0935 :: Mash h2o is too hot (obviously) so I'm air cooling.
0938 :: Mash h2o is 168F.
0951 :: Begin mash in.
0954 :: Completed mash in.
0956 :: Mash @ 152F.
1013 :: Drew off 2 gal; mash temp down to 149F; began boil @ 152F with non-sputtering flame.
1018 :: Decoction @ 166F.
1022 :: Decoction @ 181F; mash @ 149F.
1028 :: Decoction @ 206F; 60 minute boil will be done @ 1130.
1058 :: Decoction boiling nicely; mash @ 149F.
1124 :: Decoction boil continues; mash @ 148F.
1134 :: 1.5 gal decoction added back; mash to 161F.
1140 :: Sparge water on.
1156 :: Sparge water @ 106F (uh oh).
1200 :: Sparge water @ 121F.
1207 :: Sparge water @ 145F.
1215 :: Sparge water @ 172F --> pre-vorlauf.
1237 :: Heating to boil; 12 Brix.
1258 :: Boil (1.0 oz 6.4%AA German Hallertau in loose).
1343 :: Whirlfloc and IC in to sanitize.
1358 :: Flame off, chill, then whirlpool and 15' stand.
1400 :: 14.25 Brix.

Day 1
0900 :: Oxygenated for 90s @ 0.12 lpm and 0.06 lpm. The 0.06 lpm rate doesn't seem to work well - very few bubbles are visible. From now on, I'll up it to 0.12 lpm and extend it to 90s to account for loss via bubbles.
0915 :: Pitched 3/4 of the harvested yeast.

Day 2
0630 :: Lots of kraeusen and bubbling.

Day ? - 11 December
I kegged the Schwarz today. FG was 1.014, a bit high for a Schwarz, but inside the guidelines.

Oktoberfest

I've always liked Oktoberfests. I went to college in a predominantly German town that had Canada's largest Oktoberfest celebration. I've tried making one early on in my brewing career and it was poor. It lacked the mouthfeel that a good Oktoberfest has. Apparently, a decoction mash is really needed to get that and I tried two Oktoberfests using decoction. Unfortunately, not being able to directly heat my mash tun, these turned out poorly - I dumped them.

So, based on my good experience with lauter decoctions on my Schwarzbiers, I thought I'd try that for the Ofest. In a lauter decoction, you mash-in with at about 1.6 qts/lb, let the mash rest for 15 minutes, then pull off a lot of the liquid (leaving a thick oatmeal in the mash tun). You then boil this pulled fraction for 60 minutes, then add it back to the mash and let is sit for 30 minutes. After that, the process is as usual.

For yeast, I planned to use a portion of the yeast harvested from my Lawnmower Beer, but I used all of it. I know that may be too much yeast, but we'll see. The yeast from this Ofest will be the yeast that I use for my Schwarzbier.

Oktoberfest

6 gal into the primary (5.75 - 6.0 actual)

Brew date: 04 September 2010

Grist

• 9 lb 10 oz Vienna
• 1 lb 2 oz Dark Munich

Hops

• 0.625 oz German Hallertau (6.4% AA) @ 75 min

Yeast

• Saflager 34-70, harvested from the Lawnmower Beer.

Brewing Notes


Day 0
0645 :: 9 gal hot tap H2O into tun to preheat.
0705 :: 4.3 gal mash H2O heating.
0715 :: Grain temp is 72.3F so I want to mash in with 1.6 qts/lb @ 160F.
0716 :: Mash H2O is at 120F; flame was low so I turned it up.
0721 :: Mash H2O @ 150F; will stop @ 165F.
0722 :: Began draining tun preheat H2O.
0728 :: Mash H2O @ 178F ... oops.
0737 :: Mash H2O in tun; temp is 166F.
0746 :: Mash H2O in tun; temp is 161F.
0748 :: Mash in @ 160.3F; 3 minutes to put it all in and get it mixed up.
0751 :: Mash temp is 148F; stirred and @ 0753, temp was 151.5F.
0759 :: Mash temp is 151.5F.
0806 :: Began pulling off 2.08 gal for lauter decoction (the dunnmaische).
0810 :: Had to peek into mash tun to check grain, temp loss here.
0814 :: Mash temp @ 150.5F; lauter portion on to boil.
0820 :: Dunnmaische is boiling.
0820 :: Took a sample of the wort from the mash tun; cooled it; pH was between 5.0 and 5.3 (closer to 5.3) with the pH strips from www.sanitationtools.com.
0850 :: Mash temp is @ 150F.
0850 :: Currently cool and still, 48F.
0910 :: We seem to have boiled off 0.4 gal of the dunnmaische.
0920 :: Poured about 1.5 gal of dunnmaishce into the tun.
0922 :: Mash tun temp is 164F.
0935 :: Mash temp @ 165F.
1000 :: Mashout with 180F H2O.
1010 :: 4 gal first runnings, 4.5 gal second, 0.5 leftover.
1030 :: Currently @ 9 Brix (1.036).
1050 :: Boil.
1130 :: 0.625 oz 6.4% AA Hallertau hops in.
1200 :: Kettle seems to be at 7.25 gal.
1215 :: Whirlfloc and IC into kettle.
1230 :: Boil kettle volume @ 6.75, going another 15 min to get volume down and gravity up; currently 1.046 (11.5 Brix).
1245 :: Flame off.
1310 :: I decided to to a 15 min whirlpool to see if I can minimize trub; gravity going into kettle was 13.5 Brix (1.054).
1310 :: Looks like ~ 5.75-6.00 gal into primary.

Extra Notes:

1. I think I need to adjust my grain absorption number (0.136 gal/lb) downwards. Lately I've been seeing less absorption than what I was used to. This time, I had to do a longer boil to end up with 6.00 gal into fermenter.
2. Yeast harvesting is difficult. The yeast layer is very thin, so I tried to pull the trub off the bottom and then liquid off the top. Not sure how successful that was, but I got the harvested yeast + trub + beer down from ~1 gallon to ~0.5 gallon.
3. Clean sanitizing solution off refractometer before taking gravity reading - it dilutes a few Brix pts.

Day 1
0900 :: Oxygenated at 0.06 lpm and 0.12 lpm for 3 minutes. Normally I do just 0.06 lpm, but the bubbles weren't really evident so I cranked it up a bit.

Day 2
0800 :: Fermentation has taken off! Pitching all the yeast made a big difference in fermentation
lag time, hopefully not in the finished product.

Day 8
1800 :: Fermentation is now down to 1 bubble every 20-25 seconds.

Day 13
1815 :: Hydro sample shows the gravity at 1.014, smack-dab in the middle of the BJCP range (1.012-1.016).

Day ? - 11 December

I kegged the Schwarz today. FG was 1.013, right where I want it.