Munich Dunkel

I've been planning on brewing this beer for the last two years.  I have really enjoyed the two Lagers I've brewed so far (Dark Lager and Munich Helles).  They both turned out to be smooth, clean, and easy drinking beers.  There is an elegance to these styles that makes for a really nice drinking experience.  They are simple and malty but they also have a depth of flavor that stands on it's own.  These characteristics make the extra work of brewing a lager worth while.

I'm going to try brewing up a Munich Dunkel.  I'm going to up the ante on this beer by trying a decoction mash.  I am going to use a recipe from a YouTube demonstration on decoction mash by "BrewingTV" (video is here and the recipe is here).  Decoction mashing is traditionally used by German brewers to get good extraction from their grain.  It involves a stepped mash where a part of the mash is pulled off the main mash, boiled, and then added back to the main mash to bring up the temperature.  The boiling darkens the beer and (reputedly) produces unique malty flavor compounds.  There is a lot of controversy about whether decoction is worth the effort as you can probably duplicate a lot of these flavor compounds in a simple single temperature mash through the use of specialty grains.  I would like to find out myself.

Based on the video, I plan on following the following decoction process:

1. Protein Rest:  Dough in with the goal of hitting a starting temp of 122 F (Rest for 10 min)
• Will shoot for 2 quart of water per pound of grain  
2. Decoction 1:  Pull 10 quarts of the thick mash to a separate pot, heat to 158 F for a Sacch Rest (Rest for 15 min), and then boil for 10 min
3. Sacch Rest 1:  Add the decoction back to the main mash to bring it to 148 F (Rest for 30 min)
4. Decoction 2:  Pull 5 quarts of the thick mash to a separate pot and heat to a boil for 10 min
5. Sacch Rest 2:  Add the decoction back to the main mash to bring it to 158 F (Rest for 15 min)
6. Mash Out/Recycle:  Add 2 gal of boiling mash out water and cycle through RIMS until the mash is at 175 F

Doesn't seem like it should be difficult but I expect it is going to be a long brewday.  Will be interesting to see if this will be worth it.

Decoction Mash

Recipe Details:

• Grain:
• 9 lb Light Munich (10L)
• 2 lb Dark Munich (20L)
• 8 oz CaraFoam
• 8 oz Melanoidin
• 4 oz CaraAroma
• 2 oz Carafa III
• 2 oz Acid Malt
• Hops:
• 1 oz Hallertau (Pellet, 4.1% AA) at 60 min
• Yeast:
• Wyeast 2124 Bohemian Lager Yeast
• Water:
• 10 gal Spring Water
• 5 gal Tap Water
• 1 tsp Calcium Chloride
• 1 tsp Irish Moss at 15 min

Process Details:

• Batch Size:
• 6 gal (Target 6 gal)
• Mash:
• Step 1:  
• Protein Rest:  129 F for 10 min
• Decoction 1:  158 F for 15 min and then boil for 10 min
• Step 2:  
• Sacch Rest 1:  148 F for 30 min
• Decoction 2:  Boil for 10 min
• Step 3: Target Duration: 45 min)
• Sacch Rest 2:  158 F for 15 min
• Mash Out/Recycle:  Ramp up to 175 F via RIMS
• Boil:
• 60 min
• Fermentation Temp:
• Primary at 52 F
• Diacetyl Cleanup - Ramp up to 65 F
• Lager at 36 F
• Primary Duration:
• 1.5 weeks
• Diacetyl Cleanup Duration:
• 5 Days
• Secondary/Lager Duration:
• 6 weeks

Results:

• OG:
• 1.052 (Target 1.048)
• Efficiency:
• 76% (Target 70%)
• FG:
• 1.014 (Target 1.012)
• Apparent Attenuation:
• 72% (Target 74%)
• ABV:
• 4.99% (Target 4.73%)

Brewing Notes:

• 5/12/18 - Made a 2 litre starter from grain (1.055) and setup on the stir plate at cellar temperatures.  Pitched the yeast and let it propagate over night.  Was a pretty subdued fermentation with just a thin layer of foam on the top.  Tasting a sample of it the next morning revealed it had fermented it pretty dry.

• 5/13/18 - Brewday - 9:30 AM to 2:30 PM - Including setup and cleanup
• Heated 9.5 gal to 140 F
• Added 5 gal to the mash tun - Settled at 133 F
• Milled the grain.  Added CaCl to the grain
• Doughed in with the grain - temp settled to 128 F

• Let rest for 10 min
• Moved 10 quarts of the thickest portion of the grain over to a separate pot for the first Decoction.  Heated this on my turkey fryer until it was in the high 150/low 160 temperature range.  Let it sit at this temperature for 15 min
• Brought the first decoction to a boil.  Boiled for 10 min.  The mixture is noticeably darker after this
• Added the decoction back to the main mash.  Temperature of the main mash only raised up to mid 130 F with this.  Setup the RIMs to cycle until the temperature had settled to 148 F.  Mashed for 30 min.
• Pulled second decoction (5 quarts) of mash and boiled this for 10 min.  Cycled the RIMS to ramp up the main mash up to 158 F during this

• Added the second decoction back in.  This raised the temperature to high 150/low 160 F.  Cycled the RIMS for 15 more min

• Raised the RIMS temperature to 172 F and cycled while I heated 10 gal of sparge water to 180 F
• The wort is 20 brix at the end of the mash
• Fly sparged
• Drained all the wort from the grant into the mash tun.  Flushed the grant with 1 gal of sparge water to ensure everything was rinsed through the RIMS
• Started the flow of sparge water.  Drained to the grant and then pumped into the kettle
• After collecting 3 gal of wort the gravity was 13 brix
• Started to heat the kettle after collecting about 4 gal
• Stopped the sparge after collecting about 5 gal - had about 1.5 gal of water above the grain bed at this point.
• Collected ~8.5 gal.  Gravity at the grant was 2-3 brix at that point
• Had it to a boil just as the sparge ended
• Added hops when the hot break had cleared
• Boiled for 60 min
• Added irish moss with 15 min left
• Put in the wort chiller to sanitize with 5 min left
• Chilled to 70 F
• Transferred to SS Brewtech Brewbucket fermenter.  Added yeast during the transfer.
• Moved to fermentation chamber to chill to 53 F
• Collected 6 gal and measured the gravity as 1.052
• 5/14/18 - Fermentation was off to a vigorous start by this afternoon

• 5/15/18 - Still getting a bit of bubbling in the airlock.  The yeast is putting off a pretty strong sulfur aroma.  It is pretty prominent outside of the fermentation chamber as well.
• 5/23/18 - Allowed the beer to rise up to the mid 60s for Diacetyl cleanup
• 5/28/18 - Moved the beer out of the fermentation chamber to the mid-60s basement to make room for another beer.
• 6/2/18 - Moved the beer back into the fermentation chamber set to 36 F for Secondary/Lagering
• 7/12/18 - The beer has been lagering at 36 F for the last 6 weeks.  I'm planning on bottling tomorrow.  Added gelatin to fine the beer.
• 7/14/18 - Bottled this beer with 4 oz of priming sugar.  Got 59 bottles out of ~5.75 gal of beer.  measured the FG as 1.014.  The beer has retained the rich malty flavor from the wort and has a really nice clean fermentation profile.  I think its going to be very nice.  Will give it a couple weeks to carb up.
• 8/30/18 - Tasting Notes - Rich and complex malt flavor which is comparable to many of the German made examples I've had.  Easy drinking and refreshing which makes drinking 2 to 3 pretty easy.  Nice clean lager profile - it was a well executed fermentation and lager period on this beer.  One interesting note:  this beer has, by far, the least sediment per bottle of any of the beers I've made.  This hasn't prevented the normal carbonation from occurring.  The six odd weeks of lagering is likely responsible but I also gave it some extra time to fine with gelatin.  I may have to try something like this with future beers.

Lessons Learned:

1. I was impressed by the rich malt flavor of the beer.  I tasted quite a bit of the grain from the boiled decoction mash and they were very nice and rich.  I'm inclined to think that the decoction did have some flavor impact.  I think I'd like to try this again.