Courage Russian Imperial Stout Clone 1.0

I've heard quite a lot about this beer over the last couple of years, so I decided to try brewing a batch with the best recipe I could locate, adjusted for my Grainfather and a three gallon batch.  This will be the first Imperial Stout I think I have ever brewed.  I don't know where I found this recipe, and I tried to locate it again on the web with no success.  My apologies to whoever originally published it, but since I've significantly altered it below (adding DME, swapping out the flavor/aroma hops, and the yeast) that may be just as well if the beer doesn't turn out.

Ingredients

5 pounds 5 ounces Maris Otter malt
3.3 pounds (1 large can) Maris Otter LME
8 ounces English Medium Crystal malt
6 ounces English Pale Chocolate malt
2 ounces English Black Patent malt
2 ounces English Roasted Barley

1/8 tsp. Brewtan B (mash)
1.5 tsp. pH 5.2 stabilizer (mash, after grain)

10 ounces cane sugar (start of boil)
4 ounces Lyles Treacle (10 min.)
1 tsp. yeast nutrient (15 min.)
1/4 tsp. Brewtan B (20 min.)
1/2 tsp. Irish Moss (10 min.)

0.5 ounces Warrior hops @ 60 min.
0.25 ounces Target hops @ 15 min. (swapped for Willamette 4.8% AA last minute)
0.25 ounces Target hops @ 5 min. (swapped for Willamette 4.8% AA last minute)

1 packet Mangrove Jack's New World Strong Ale yeast, replaced with Lallemand CBC-1 yeast which has a higher alcohol tolerance needed for the OG obtained

2.6 gallons of RO water for mash
2.5 gallons of RO water for sparge
Treat the mash water with 1.4g baking soda, 1.5g calcium chloride, 1.2g canning salt, 1.4g epsom salt, 2.6g gypsum, 1.4g magnesium chloride

0.25 ounces Medium Toast American Oak Chips

16 ounces Pilsner DME added to bring gravity up

Brewfather estimates that the beer will have the following characteristics:

• BJCP Style:  20.C Imperial Stout
  
• Batch Size: 3.0 gallons estimated, 2.65 gallons actual
• Pre-Boil Volume:  4.5 estimated, 4.4 gallons actual
• Original Gravity:  1.107 SG estimated, 1.121 SG actual
• Pre-Boil Gravity: 1.032 SG estimated, 17 Brix on refractometer, approx. 1.065 SG
• Final Gravity: 1.030 SG estimated
• IBUs: 58
• ABV: 13.1%
• SRM: 39.5
• BU/GU Ratio: 0.49
• Fermenter: ?
• Bottling Wand: n/a
• Carbonation Method: n/a 
• Tilt Hydrometer:  Green

Mash Schedule:

• Put 2.6 gallons of water in The Grainfather and add the salts
• Heat water to 120F and begin stirring in the Maris Otter LME until dissolved
• Add the grain and some rice hulls, stirring well to make sure all grain is moistened
• Add the mesh grain bed cover and overflow cap
• Adjust the pump flow so that wort trickles over the cap
• Mash at 120F for 20 minutes
• Mash at 140F for 15 minutes
• Mash at 156F for 45 minutes
• Mash out at 168F
• Sparge with 2.6 gallons RO water (room temp or 168F, your choice, both will work)

Boil Schedule:

• 180 minutes: No additions
• 60 minutes: Warrior hops
• 20 minutes: Brewtan B
• 15 minutes: Target hops, yeast nutrient, Irish Moss
• 5 minutes: Target hops
• 0 minutes: Chill and pump into fermenter

Fermentation Plan:

• CBC-1 ferments optimally at 72F.  This time of year, my basement is around 65-68F, so if I start fermentation low enough it shouldn't get much above 72F even without temperature control.
• Once gravity is down to around 1.035 SG, I'll be adding the oak chips to primary. This will minimize the risk of introducing oxygen into the beer (since fermentation should still be underway and CO2 can push out any oxygen I introduce putting in the chips) and still allow the oak to infuse the beer.
• When the oak is properly infused, I'll bottle directly from the fermenter and use 3 small Brewer's Best carbonation tablets per bottle (low carbonation).

Brewing Notes and Observations

10/24/2020:  Using Brewfather's ability to transfer a recipe to The Grainfather's controller, the brewing process went pretty smoothly.  The Grainfather dutifully changed temps when needed to follow the mash schedule and all I had to really do was keep an eye on wort flow.

When I smelled my Target hops, they smelled a bit soapy to me, so I did not want to take the risk of using them as flavoring and aroma hops, so I dumped them and switched to the closest substitute I had at the time, which was Willamette.

When I checked the gravity a good bit through the boil, it was running a bit low, so I added a pound of Pilsner DME.  In the end, though, it turned out to be unnecessary as the gravity was a bit high at the end of the boil.  One the wort was in the fermenter, the temp was too high for the yeast, so I let it cool down naturally until it was in range.

10/25/2020:  The temperature dropped to 68F overnight.  I pitched the yeast around 2:45pm.  I switched from Mangrove Jack's yeast to Lallemand CBC-1 because the high gravity seemed to lend itself to a tougher yeast. CBC-1 is said to leave behind a more full-bodied beer with some residual sugar, which should work well with the significant IBUs in this beer.

10/26/2020:  The temperature is currently reading 69F and the gravity has dropped to 1.108 SG.  I saw a healthy looking krausen atop the wort last night, so it's clear that fermentation is underway.

10/27/2020:  Gravity is 1.085 SG today, and the temp has dropped back down to around 68F.

10/30/2020:  Gravity has continued to drop gradually, and is currently 1.058 SG.  The temperature has been holding steady at 67F.  The current level of attenuation represents approximately 10% ABV.

11/2/2020:  Last night, I swirled the fermenter well to ensure that the yeast remained in suspension.  Prior to that, the gravity reported as 1.048 SG.  Today it's reporting as 1.050 SG.  I added a drop of glucoamylase enzyme, after which gravity began dropping again.

11/3/2020:  Gravity is 1.046 SG today.  

11/7/2020:  Temperature has been holding pretty consistently at 66F.  Gravity has continued to steadily drop, and currently registers 1.029 SG, making the beer approximately 14% ABV.  Oak cubes were added on Thursday while fermentation was still active, to guard against oxidation.

11/19/2020:  Gravity has dropped to 1.012 SG, which represents about 16.3% ABV.  That's slightly over the yeast's rated tolerance of 16.1% ABV, so I don't expect it will drop much further.  Hopefully I can get it to carbonate in the bottle once fermentation seems to have stopped (which it hasn't yet).

12/11/2020:  I chilled and opened a bottle tonight.  Well-carbonated.  Lots of chocolate in the aroma.  Nice roasty flavors behind the chocolate.  A decent warming note.  Relatively light-bodied, which makes it surprisingly easy to drink for 16.5% ABV.