Russian Imperial Stout with Bourbon Soaked Oak - Take IV

This is my fourth attempt at making a clone of the famous Goose Island Bourbon County Brand Stout (read about First, Second, and Third attempts).  This is a big Russian Imperial Stout (14-15% ABV) which is aged in freshly emptied Bourbon Barrels.  Bourbon Barrel aged RIS are pretty common these days but BCBS is the most Bourbon forward version that I've tried - it is really awesome.

The first three attempts made tasty beers but they all fell short of the mark as clones (read about my most recent vertical tasting here).  I have taken a few key lessons from these beers:

1. This beer finishes at around 1.038 which is a challenge to hit.  Coming in much higher than this is going to result in a beer that doesn't match the balance of the real thing
2. Aging with a ratio of oak to beer which matches the oak surface area to beer ratio in a 53 gal bourbon barrel (56 sqin per gal) is necessary to match to potency of the booze character
3. Preparation of the oak is a critical factor in order to get the bourbon flavor of BCBS.  I am aging with Everclear diluted down to Barrel Strength spirit (~63%).  The toast and char levels are the key factor in determining the flavor of the spirit.  Bourbon is a mix of Vanilla and Caramel flavors and getting the correct balance of the two seems to primarily be a function of how much the oak is toasted. 

I will be brewing the same recipe at the previous versions.  The difference this time is how I choose to address the lessons learned above.  I ran a 12 sample experiment on the toast and char level which can be read about here.  This has guided me on how much I should toast and char my oak in order to get a flavor that is primary vanilla with hints of caramel (a balance like Bourbon).

Like with previous beers, I will be doing a primary fermentation to get down to FG and then will age the beer on my bourbon soaked oak for about a year in a non-climate controlled attic.  This will allow for better exchange between beer and oak.

This is a challenging beer to make in all regards (lots of work to create such a sugary wort, challenging fermentation to get such a high ABV, and difficult to approximate the character of a freshly drained bourbon barrel) but I still love making the attempt.  I look forward to taking more lessons from this latest version.

Recipe Details:

• Grain:
• 22 lbs Pale Ale
• 8 lb Light Munich
• 2 lb Crystal 60L
• 1.5 lb Chocolate Malt
• 1.5 lb Roasted Barley
• 12 oz Black Patent
• 4 oz Acid Malt
• Hops:
• 3 oz Chinook (Leaf, 12.2% AA) at 60 min
• Yeast:
• Wyeast 1099 - Whitbread Ale Yeast (3nd Pitch)
• White Labs 099 - Super High Gravity Yeast (2nd Pitch)
• While Labs 090 - San Diego Super Yeast
• Water:
• 20 gal Spring Water
• 2 tsp CaCl
• 2 tsp Gypsum
• 1 tsp Irish Moss

Process Details:

• Batch Size:
• 6.5 (Target 6.5 gal)
• Mash:
• 152 F for 60 min
• Boil:
• 4.5 hrs (Target 4 hrs)
• Fermentation Temp:
• 68 F (Ambient Basement Temps)
• Primary Duration:
• 4 weeks
• Secondary Duration:
• 8 to 12 months

Results:

• OG:
• 1.128 (Target 1.128)
• Efficiency:
• 66% (Target 66%)
• FG:
• 1.042 (Target 1.038)
• Apparent Attenuation:
• TBD (Target 68%)
• ABV:
• TBD (Target 12.1%)

Brewing Notes:

• 9/4/22 - Oak Preparation:
• Cut 12 1x1x6 inch pieces of oak which I had seasoned outside for a couple years
• Toasted these on a cast iron pan on 2/3 above low temperature (Low +2)

Toasted - A bit of variability to the toast levels here

• Charred the oak with a propane torch until black (3 pass char)

L to R - 3 Pass Char, 2 Pass Char, and 1 Pass Char

• The oak weighs:

• Made a barrel strength spirit using 95% alcohol Everclear and spring water.  This is about 62% ABV.  Prepared 4 half gal jars

• Put three sticks in each jar

• Moved the jars up to the hot attic to extract the flavors
• 10/1/22 - Brewday - 12:30 PM to 9:00 PM- Including Setup and Cleanup
• Heated 12 gal of spring water up to 185F
• Milled half my grain.  Added half the CaCl and Gypsum to the grain
• Added 7 gal of strike water to the mash tun.  Cycled through the grant and RIMS until the system stabilized at 162 F
• Mixed in the grain - stirred well to eliminate doughballs.  Let the mash sit for 10 min to settle out then cycled through the RIMS at 152 F for 50 min
• Fly sparged the mash until 7 gal of wort was collected in the mash tun.  Started the heat after collecting 4 gal of wort.  Started the 2 hr boil

• Collected a few more gal of wort from the mash tun to use as strike water in the next mash and set this aside before cleaning out the mash tun
• Heated 10 more gal of strike water, for the second mash, to 185 F
• Milled the other half of the grain and added other half of Gypsum and CaCl to the grain
• Added remaining previous mash water and strike water to the mash tun to get 7 gal.  Cycled this through the RIMS until the temperature reached 162 F
• Stirred in the remaining grain and made sure there were no doughballs.  Let this sit for 10 min and then cycled the rims for 60 min
• At the end of the 2 hr boil I had about 3 gal of wort
• Fly sparged the second mash until 10 gal of wort had been collected.  Continued the boil while doing this collection
• Boiled the beer for 2 more hours

• Added bittering hops at 60 min
• With 15 min I added the Irish Moss
• Added the wort chiller with 5 min left to sanitize
• Chilled the beer down to about 80 F
• Transferred to a fermenter - let the beer fall a foot or so to aerate

• Moved the fermenter to my chest freezer to chill down to 68 F
• Collected about 5.9 gal of wort which measured in gravity as 1.142.  This is just about on target for efficiency but I over reduced.  Added spring water to get to 6.5 gal
• 10/2/22 - Split the beer across 2 fermenters and pitched my yeast.  Left them at ambient basement temps to ferment
• 10/17/22 - Gravity is down to 1.052 after 2 weeks of fermentation.  Transferred the beer into one fermentor and pitched my White Labs 099 - Super High Gravity yeast to try to get down to 1.038.  I still have about 6.5 gal
• 10/30/22 - The gravity is measuring 1.054 today - it hasn't dropped at all in 2 weeks.  I am going to get some more High Gravity yeast to finish this up
• 11/3/22 - Pitched a starter of WLP 090 (San Diego Super Ale Yeast) built with a fresh pack.  Hopefully this will drop it another 15 points - fingers crossed
• 11/12/22  - Measured gravity again - it is now down to 1.052.  I stirred up the yeast cake and put some heating pads next to the fermenter to try to kick fermentation back up
• 11/20/22 - Moved the beer up to the main house in front of a heating vent.  Started seeing some bubbling soon after this.  The the beer is now down to 1.047 so I'm encouraged.  I gave it a stir with the auto-siphon as well.
• 11/27/22 - The gravity is now down to 1.045
• 12/18/22 - The gravity is now down to 1.042.  It doesn't taste overly sweet to me.  I'm 4 points higher than target but I think this is going to be close enough.  Transferring the beer onto the oak for secondary now
• Measured the weight of the oak post aging on spirit.  It had been 2 lbs and 2.7 oz.  Now it is 3 lb 5.7 oz.  This is an increase of 19 oz by weight and 20 oz of spirit.  This is about 1.6 oz of spirit per stick of absorption.  A fair bit lower than the 2.5 oz per stick I had received last time (the attic, where these had been sitting, has gotten down to the 30 F range so maybe that's why the wood isn't currently holding as much spirit as before).  Adding 10 oz of the spirit to the fermentor as well to compensate for this

• Transferred the beer onto the oak in a large bucket fermenter.  Got about 6 gal of beer at this stage.  Moved the beer up to my attic to age for the next 10 months