Munich Dunkel Take II

This week I'll be brewing up a Munich Dunkel.  This is one of my favorite styles of beer and will be my second attempt at making one (read about the first here).  This is a dark lager beer that makes use of Munich Malt and a decoction mash to get a sweet bready and toasty malt character.  They are really delicious.  I'll be kegging this beer.

For my previous version, I used a recipe that used Munich and then a number of specialty malts for complexity.  This time I'm going the simple route with a grain bill of Munich only.  I'll do a triple decoction mash.  Decoction, if you're unfamiliar with it, is a traditional process used to get better extraction from grains.  It originated from a time where grain were lower quality and wouldn't provide good extraction with a singe infusion.  It involves pulling a portion of the mash, boiling it, and then adding it back to the main mash to increase the overall temperature to put it in the ranges of the various enzymes.  In the process of boiling the gain and wort are darkened and (in theory) new, malty, flavors are created.  I'll be doing three boils for this beer.

For hops, I'll be using a traditional German variety - Tettnang.  It is a very mildly hopped beer style.  I'll go with just 2 oz of low Alpha Acid hops (at 1 hr and 30 min).

For yeast, I have a packet of Wyeast 2124 Bohemian Lager.  I'll make up a 1 Litre starter and ferment at 50 F.  I'll give it 3 weeks to ferment, 1 week at warmer temps for Diacetyl cleanup, and then 4 weeks of lagering

I'm going to shoot for a beer with somewhere between 5 and 6 percent ABV.

Recipe Details:

• Grain:
• 12 lb Munich
• 2 oz Acid Malt
• Hops:
• 1 oz Tettnang (Pellet, 3% AA) at 60 min
• 1 oz Tettnang (Pellet, 3% AA) at 30 min
• Yeast:
• Wyeast 2124 Bohemian Lager
• Water:
• 12 gal spring water
• 1 tsp CaCl
• 1 oz Irish moss at 15 min

Process Details:

• Batch Size:
• 6 gal (Target 6 gal)
• Mash:
• Triple Decoction:
• See details in brewing notes
• Boil:
• 60 min
• Fermentation Temp:
• 50 F for primary
• 65 F for Diacetyl Cleanup
• 32 for Lager
• Primary Duration:
• 4 weeks
• Secondary Duration:
• 4 weeks

Results:

• OG:
• 1.058 (Target 1.055)
• Efficiency:
• 76% (Target 72%)
• FG:
• 1.010 (Target 1.014)
• Apparent Attenuation:
• 82% (Target 74%)
• ABV:
• 6.3% (Target 5.4%)

Brewing Notes:

• 10/31/20 - Built a yeast starter using 1 L of water and 100 g of dry malt extract.  Set this up on a stir plate to propagate

• 11/1/20 - Brewday - 6 AM to 11:30 AM - Including setup and cleanup
• Heated 6.5 gal of spring water to 160 F
• Milled my grain.  Added CaCl to it
• Stirred in the grain and broke up any dough balls
• Let the mash sit for 15 min - temperature settled out at 140 F
• Moved 10 quarts of the mash (taking grain and leaving most liquid behind) to a separate pot.  Heated this up to the high 150s and let it sit for 15 min.  Then brought this to a boil for 10 min
• Added the decoction back to the mash tun.  The main mash had settled to 125.  Adding the decoction raised it to 160 F.  I added half a gal of 60 F water and that overshot me back down to 147 F.   Let this sit for 15 min at this temperature
• Pulled 5 quarts of mash and boiled this for 10 min
• Added the decoction back to the mash.  It had fallen to 143 F.  This raised it up to 156.  Let this rest for 15 min

• Heated 7  gal of spring water for the sparge to 180 F
• Pulled one final decoction (5 quarts) and boiled for 10 min while waiting for the strike water to finish.
• Added it back to the mash tun and let it sit for 10 min
• Batch sparged.  Started heating the kettle after collecting 3 gal.  Had it to a boil during the second batch sparge.  Collected 8 gal of wort
• Added my bittering hops
• Added 30 min hops
• Added Irish Moss with 15 min left
• Added wort chiller to sanitize with 5 min left
• Chilled down to about 70 F
• Drained into a bucket fermenter - the the wort fall a couple feet to aerate.  Collected about 5.4 gal of wart
• Measured the gravity as 1.064 which is 76% efficiency

• Topped it up to 6 gal which should bring the gravity down to about 1.058
• Pitched my yeast
• Moved the beer to the chest freezer to cool down to 50 F for fermentation 
• 11/2/20 - The fermenter was bubbling slowly by the next afternoon
• 11/8/20 - Still bubbling after a week
• 11/19/20 - Moved the beer out of the chest freezer to warm up and do a diacetyl cleanup
• 11/30/20 - Moved to the chest freezer set to 50 F initially.  Will lower this further later in the week
• 12/1/20 - Dropped the temperature to 40 F
• 12/24/20 - Transferred the beer into a purged keg.  Measured the gravity of the beer as 1.010.  Set it up to carb at 12 PSI.  The beer actually has a fair amount of natural carbonation as well which is interesting.  Ended up with 2 extra pints at the end which I'll drink today.  Saved the yeast cake in 2 jars for use in future beers.
• 3/31/21 - Tasting Notes - This has a very nice malt character to it.  I really like the Munich Dunkel style.  I also very much like the later yeast character and enjoy the interplay between the malt and yeast here.  This is a fairly strong beer at 6.2%.  This doesn't hurt it but does make it more difficult to choose this as a second pour.  I'd aim for a bit lower next time.