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Monday, November 2, 2015

Russian Imperial Stout with Brettanomyces Take II

The Russian Imperial Stout that I brewed last year has been bulk aging with Oak and Brett for just about 10.5 months.  It is smooth and mellow with really nice roast, coffee, and chocolate flavors.  It absolutely doesn't taste like a 10%+ beer.  I think it has aged enough at this point and want to start drinking some of it this winter.  This will be a batch to replace it in the glass carboy.

I will be sticking with the same grainbill as it seemed to have worked out really nicely.  I gave the LHBS an incorrect value so this batch will have 5 lbs of amber malt rather than the 4 lbs in the last batch.  I will also be mashing with the same 162 F I used for the last batch.  The last beer fermented down to 1.036 after primary and then after a month in secondary with the Brett it was down to 1030.  The gravity stayed there for a good 5 months but somehow the summer heat allowed fermentation to kick up again and the beer got down to 1.022.  We'll see if it manages to get any further at bottling time.

The Brett character in the first iteration of the beer was, at best, very subtle or, at worst, not there at all.  I'd like to increase that for this round if I can.  To that end I will be doing a warmer primary (70 F as opposed to the low 60s used for last batch) with an expressive English yeast (Wyeast 1318 London Ale III from this Robust Porter).  I am also going to deliberately under pitch, with 4 cubs of slurry,  My thought is that under pitching and the warmer fermentation temperature will cause the yeast to produce beer with more fruity esters.  The brett would then (theoretically) convert the fruity esters from the primary and create some earthy or leathery character from them.

The previous beer had inoculated oak cubes added to it to get the brett secondary fermentation started.  I will just use this brett to drive this fermentation as well (in addition to any dregs are at the bottom and a qt or so of beer that I'll likely leave behind with them).  I will add a second ounce of fresh oak cubes in case a lot of oak character has faded in the current ounce.


Finally, I am going to go with a vented silicon bung for this round to see if a bit more oxygen exposure could help the brett along.  This could backfire on me and allow the brett to supper-attenuate but I am willing to risk it.

Recipe Details:
  • Grain/Adjuncts:
    • 13 lb Maris Otter
    • 5 lb Amber Malt
    • 1 lb Brown Malt
    • 8 oz Black Malt
    • 2 lb Black Candi Sugar
  • Hops:
    • 2 oz Target (Pellet, 9.8% AA) at 120 min
  • Yeast:
    • Wyeast 1318 London Ale III (Second Pitch)
      • 4 Cup Slurry from Robust Porter
    • White Labs 645 Brettanomyces Claussenii (Third Pitch)
      • From 1 oz of inoculated oak cubes
  • Water:
    • 10 gal spring water
    • 9 gal tap water
    • 1 oz Calcium Chloride in mash
    • 1 oz Gypsum in mash
    • 1 oz Calcium Chloride in boil
    • 1 oz Irish Moss at 20 min
  • Extras:
    • 1 oz oak cubes from previous batch
    • 1 oz medium toast oak cubes
    • 10 handfulls of rice hulls

Process Details:
  • Batch Size
    • 6 gal (Target 6 gal)
  • Mash:
    • 162 F for 60 min (Target 162 F for 60 min)
  • Boil:
    • 120 min (Target 120 min)
  • Fermentation Temperature:
    • 70 F
  • Primary Duration:
    • 4 weeks
  • Secondary Duration:
    • 48 weeks

Results:
  • OG:
    • 1.102 (Target 1.100)
  • Efficiency:
    • 76% (Target 75%)
  • FG:
    • TBD (Target 1.025)
  • Apparent Attenuation:
    • TBD (Target 73%)
  • ABV:
    • TBD (Target 9.84%)

Brewing Notes:
  • 11/1/15 - Brewday - 1 PM to 6:15 PM including setup and cleanup
    • Heated 10 gal of spring water and cycled through the Mash Tun and RIMS until the system was at 165 F
    • Ended up with 6 gal above the false bottom
    • Setup the RIMS to cycle at 2 qts per min at 164 F
    • Added the CaCl and Gypsum
    • Added the grain and stirred in to eliminate dough balls
    • After 10 min the mash was at 157 F.  Gave it a stir and raised the RIMS to 166 F
    • Started to get a stuck sparge.  I added 5 handfulls of rice hull and stirred in.  Still stuck so I added 5 more handfulls.  This seemed to do the trick.
    • Stirred after 30 min.  Temp was up to 159 F.
    • Brought 10 gal of sparge water up to 185 F
    • Stirred after 45 min - mas was 162 F.  Lowered the RIMS to 164 F.
    • Drained the grant volume back to the tun and added sparge water until there was about an inch of water above the grain bed
    • Set the sparge up for about 1 gal every 5 min
    • Started heating the kettle after collecting a couple gal.  It was to a boil after collecting about 8 gal
    • Added more CaCl to the kettle during the sparge
    • Collected 10 gal
    • The gravity in the grant at the end of the sparge was 3.5 brix (1.014)
    • Added the hops after the hot break cleared
    • Added the irish moss with about 20 min to go in the boil
    • Added the candi sugar with about 5 min left in the boil
    • At the end of the 120 min boil I added the wort chiller to sanitize
    • Chilled down to 70 F and then transferred into the fermentor.  Let fall a foot to sanitize
    • The wort is super sweet - 1.102 and very bitter.  Collected 6 gal
    • Moved to the fermentation chamber with reptile heater at 70 F
    • Added 4 cups of yeast slurry (forgot to sanitize the measuring cup - oops) and setup with a blowoff tube as I'm anticipating a very vigorous fermentation
  • 11/2/15 - The beer is bubbling vigorously this afternoon.  The chamber is holding steady between 70 and 72 F
  • 12/13/15 - Transferred this beer into the carboy previously used for my first RIS with Brett.  Measured the gravity as 1.030.  The warmer fermentation temperature seems to have done the trick - the fruity esters are pronounced both in aroma and flavor.  Hopefully this will give the Brett a bit more to work on (as planned).  The beer is very bitter and has a lot of body.  I'm sure both of these will fade quite a bit with the long aging.  Added the additional ounce of oak cubes during the transfer - hoping this won't be too much.  Set the fermentor up with a vented silicon bung.  Will age the beer for the next year.  I'm not planning on taking another sample of this one until next October.


Lessons Learned:
  1. I was getting a stuck sparge during cycling.  I'm sure this was not helpful for my efficiency.  I need to adjust the grain mill a bit to reduce the crush for the next batch.

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