Russian Imperial Stout with Brettanomyces

I was inspired to brew this batch by The Mad Fermentationist's version of Courage Russian Imperial Stout which is a big Russian Imperial Stout with Brettanomyces yeast and oak in secondary.  The original Courage Russian Imperial Stout, which was discontinued in the 1980s, was reputed to have a leather character from the brett which sounds very intriguing to me.  Add to that the fact that I had the primary yeast strain lined up from the Brown Porter I was just about to bottle and the brett strain from my Berliner Weisse I decided to try it out.

From reading the tasting notes you get the impression that the Mad Fermentationist's version never really developed the leather of the original and that the brett contributed a lot more to the aroma than the flavor.  I am going to try an alternate approach with this beer that will hopefully allow me to a get more brett character.

Brett has the potential to take the final gravity very low (my Berliner Weisse finished at 1.002).  This could leave the beer with a watery/boozy/harsh/astringent flavor if I'm not careful.  Ideally, I think this beer would finish around 1.025 but I'd be okay with it down to 1.018 or so.  In the Mad Fermentationist's clone the brett managed to chew the beer down from 1.030 to 1.020 in about two months so he had to kill it with campden tablets to preserve that much residual sugar.  It seems likely that this 2 months spent with the brett wasn't enough to allow the complex flavors to fully develop - I am thinking that a more extended aging period (10 months maybe) would go a long way towards allowing the brett flavors to come to fruition.  The trick will be to let the brett work but also leave the beer with a reasonable final gravity.  With that goal in mind I am going to attempt to control the brett behavior by doing the following:

1. Using a very high mash temperature - I am thinking 162 F will be a good one to help ensure that the primary yeast leaves the beer at a fairly high gravity.  My hope is that it also creates some sugars that the Brett isn't able to handle (not holding my breath on this one).  At the least it will give me some extra margin if the brett is able to crew through a lot of the sugar.  I am thinking if primary fermentation stops in the mid 1.03 range then that's a fairly good sign.
2. Try to limit the oxygen content and exposure of the beer in secondary - the thought here is that less oxygen will mean that the brett has a harder time building up it's ranks and that it will be more likely to stall out earlier.  To do this I will give the primary yeast 1 month to ferment out and then I will give the beer an additional month in a better bottle secondary prior to pitching the brett.  I will fill the better bottle up to the neck to try to limit oxygen exposure.
3. Low pitch rate for the brett - I am going to build up a brett "starter" using 2 liters of my brown porter and some bottle dregs from my berliner weisse which contains brett C (as well as wine yeast and lacto which I'm assuming will not like their environment too much).  I will let this grow for a couple months and add oak cubes to it at some point.  Depending on the flavor and the gravity drop I may pitch the whole thing or I might just drop in the inoculated oak cubes

Hopefully a combination of these three actions will give me a good chance of both having a reasonably strong contribution from the brett and a good level of residual sugar in the finished product.  Ultimately I think I will lean more towards the brett flavor if I have to choose so I'll likely let it age all the way out even if it over attenuates.

I really like a big stout but I was also thinking that 10% alcohol (as was the case for the original) might be a bit on the high side for me if I plan on drinking an entire bottle.  So, I've planned for it to come in around 8.5% at my normal efficiency.  If it turns out to be a bit higher or lower that doesn't hurt my head much.

I am thinking of giving this beer about a year to finish out - should be bottling in winter 2015!

Recipe Details:

• Grain/Adjuncts:
• 13 lbs Marris Otter
• 4 lbs Amber Malt
• 1 lb Brown Malt
• 8 oz Black Malt
• 2 lbs Dark Candi Sugar
• Hops:
• 2 oz Target (Pellet, 9.5% AA) at 120 min
• Yeast:
• Wyeast 1028 London Ale
• 6 cups Slurry from Brown Porter (Target 8.5 cups)
• White Labs 645 Brettanomyces Claussenii in Secondary
• Harvested from Berliner Weisse Bottle Dregs
• Red Star Premier Cuvee Wine Yeast (at bottling)
• Water:
• 13 gal Spring Water
• 2 tsp Calcium Chloride
• 1 tsp Gypsum
• 1 tsp Irish Moss at 20 min
• Extras:
• 1 oz Medium Toast Hungarian Oak Cubes

Process Details:

• Batch Size:
• 6 gal
• Mash:
• 162 F for 60 min
• Boil:
• 120 min
• Fermentation Temperature:
• Start at 60 F allowed to raise to 64 F
• Primary Duration:
• 5 weeks
• Secondary Duration:
• 47 weeks
• Brett added after 4 weeks in Secondary

Results:

• OG:
• 1.100 (Target 1.090)
• Efficiency:
• 79% (Target 70%)
• FG:
• 1.022 (Target 1.025)
• Apparent Attenuation:
• 77% (Target 71%)
• ABV:
• 10.24% (Target 8.53%)

Brewing Notes:

• 11/16/14 Brew Day - 2:15 PM to 9:00 Including setup and a lengthy break for dinner
• Saved off 2 liters of Brown Porter from my previous batch in a flask to try to culture some Brett.  Poured in the dregs from two bottles of Berliner Weisse.  Added 1 tsp of the Brown Porter yeast cake to the flask to give the Brett some additional food

• Brought 10 gal of Spring Water up to 194 F - took 35 min
• Added 23 qt to the mash tun (kept the kettle running after this)
• Added Calcium Chloride and Gypsum to the mash tun
• Let the temperature settle for 10 min - temp ended up at 181 F
• Added the grain, stirring well to eliminate doughballs.  Temperature ended up a bit high at 165 F.  Stirred more until it got down to about 162 F
• After 30 min I stirred the mash and measured the temperature as just about 162 F
• Added 3 more gal of spring water to the kettle and brought it up to a boil
• After 60 min the mash was about 160 F
• Added 14 qt of near boiling mashout water to bring the mash up to 170 F
• Saved 4 gal of hot water for the batch sparge in two small pots
• Stirred the mash then vorlaufed and drained slowly into the kettle - took 40 min to collect 7 gal
• Added 4 gal of sparge water - ended up at 150 F.  Stirred, vorlaufed, and drained slowly - took 20 min

• Brought the 7 gal of wort to a boil while doing the batch sparge - took 30 min
• Ended up with 10 gal of wort
• Had a pretty nasty hot break on this batch - a bit got over the edge of the pot
• Added the hops after the hot break had cleared
• Once the kettle had gotten down to 6.75 gal I added the irish moss
• Once the kettle was down to 6.5 gal I added the candi sugar.  Stirred vigorously to help it dissolve

• Added the wort chiller at flameout to sanitize.  Chilled down to ground water temps (mid 50s) in about 30 min
• Transferred to the fermentor.  Poured the beer back and fourth between the fermentor and bottling bucket to aerate
• Put the fermentor in the chest freezer and ladled the yeast cake from the Brown porter into the RIS.  Set it up with a blowoff tube as this will likely be a very vigorous fermentation.  The beer was at 58 F at this point.
• Collected about 6 gal of wort.  Measured the original gravity as 1.100 at 64 F which is 10 points higher than planned.  This is 79% efficiency - not sure what I did to get that.
• 11/17/14 - No bubbling in the airlock yet after 24 hrs.  The beer is now up to 61 F.  I think the lid on this fermentor may not seal perfectly either so I might not get any airlock bubbling.
• 11/18/14 - The fermentor was bubbling and blowing off at very good pace this afternoon and some beer had been pushed out the lid.  Probably lost a quarter of a cup due to this.

• 11/19/14 - Added another bottle of BW dregs to the brett starter.  The fermentor had stopped bubbling so I checked the lid and found that it had opened a bit where the beer was leaking out - re-seated the lid.
• 11/22/14 -  Beer is still bubbling.  The brett starter has started develop a thin pellicle - good sign as I wasn't sure there would be much viable brett or lacto in the bottle dregs.  Now the question is whether the lacto will contribute anything in the ~25 IBU Brown Porter - I doubt it will.  It didn't really produce any real sourness in the Berliner so I'm not too worried that it will add anything offensive in this beer.  No aroma contributions from the brett or lacto yet as far as I can tell.

• 11/29/14 - Fermentor is no longer bubbling.  The pellicle on the starter has thickened up a bit and there's a bit of a cheesy smell to it.
• 12/18/14 - It has been about a month since brewday.  It was a very vigorous fermentation.  Pulled a sample and measured the gravity as 1.036.  The high mash temperature had the desired effect - I was hoping primary would stop in this neighborhood.  The beer is a very dark red rather than black - probably due to all that amber malt.  It has a really complex malty flavor with chocolate and coffee mixed in.  Also has a very firm bitterness at this point.  No fusel alcohol.  Even with the high gravity it doesn't really taste overly sweet - I wont be upset if the Brett doesn't take the gravity too much further.  Poured most of the sample into the brett starter to give it some more to munch on.  I will transfer to secondary this weekend. 

• 12/20/14 - Transferred to a better bottle for secondary.  Had enough beer to fill up to the neck.  Boiled 1 oz of oak cubes to extract some of the oak flavor and then transferred half the cubes to the secondary and half to the Brett Starter.  Tasted a sample of the Brett starter - no real brett flavor has developed so far.
• 12/21/14 - Tasted a bit of the starter - no funk yet (which isn't unexpected given the short amount of time it's had).  I added a couple more bottles of Berliner Weisse dregs.
• 1/5/15 - Added two more bottles of Berliner Weisse dregs to the starter
• 1/16/15 - It has been about a month since I added oak cubes and transferred to secondary - the brett starter has developed a bubbly pellicle in that time.  I have decided to transfer to a different secondary (6 gal glass carboy) along with the entire brett starter for the remainder of the aging.  The better bottle is filled up to the neck and I have a bit more than 2 liters of brett starter so I would have to throw away some beer to add the brett.  Additionally, if the brett happens to kick off any strong fermentation I would end up with a pretty big mess with such little head space.  The carboy will give me quite a bit more head space and I can use the entire starter without dumping any beer.  Transferred the beer  and oak over and then swirled the remaining cup the siphon didn't get to also transfer the small amount of yeast at the bottom of the better bottle.  Did the same thing with the flask of brett starter.  I pulled a sample prior to the transfer and measured the gravity as 1.036 which is what it was after primary.  It's very rich with roast and chocolate.  It doesn't taste overly sweet even at this high gravity.  The oak doesn't have a major presence in the flavor which is a little surprising.  The alcohol is well blended which is nice.  I would be happy to bottle and drink it as is but I still like the plan with the brett.  I will check on the gravity in a month to see how the brett is doing.   

Brett Starter

• 1/25/15 - Checked the fermentor after a week and found small patches of bubbles on the surface.  Looks like there's something doing a bit of work in there but not too vigorously.

• 2/18/15 - It has been about a month since I pitched the brett into this beer.  Measured the gravity as 1.030.  So, it is down about 6 points.  It is a very rich, flavorful, beer.  Roast, chocolate, coffee, and alcohol are the dominant flavors I'm getting.  I'm not tasting anything that I can pin-point as the oak but it could just be well integrated.  Also not sure if I would say there are any brett flavors that stand out yet - maybe a slight mustiness on the nose.  I am going to give this two more months to mature at this point before taking another sample.  I'm happy that the brett is eating but not going hog wild on this beer.  Will be interesting to see how low it can take it.
• 4/20/15 - It has been two months since the last gravity sample and three months since pitching brett into the beer.  For this sample I'm measuring gravity as 1.032 - there's a bit of carbonation to the beer so this might be a bit higher than actual.  In any event the brett has not made any dent on the gravity.  The beer tastes pretty much like it did 2 months ago - good roast, coffee, and chocolate - still no brett flavor but maybe a bit of mustiness on the nose.  May be getting a bit of vanilla from the oak on the nose as well.  It's a really nice complex beer as is and it hides the 9% alcohol extremely well.  I'm hoping the brett starts to contribute a bit more flavor over the next 6 months but even if it doesn't I'll still have a pretty great beer.  I'll check on this beer again in 3 months.

• 7/30/15 - Pulled another sample which measured at 1.032 still.  The main flavors are still roast/coffee/chocolate.  Oak and maybe a small bit of brett character are in there but much less prominent.  The finish is a bit sweet with a bit of alcohol burn - not much in the way of bittering hop flavor left.  I'll give this beer 3 more months before bottling.
• 10/11/15 - I plan on bottling this next month so I've taken another sample.  It is down to 1.022 somehow - it was holding steady at 1.032 for several months in secondary and I hadn't expected a further drop.  I'm curious to see if it will drop any more in the next month - I may have to hold off on my bottling plans.  It is still a very smooth beer at this gravity with nice refined roast flavors.  It also seems to have mellowed and smoothed out over the last couple months.  At this point I'm not really getting much in the way of flavor contribution from the brett - may be a slight earthiness to the beer from it but it could also just be age.
• 12/13/15 - Bottled with re-hydrated dry wine yeast and 2.5 oz of priming sugar.  Collected about 5.75 gal of beer which got me 56 12 oz bottles.  I left about a quart at the bottom of the carboy to help get RIS with Brett II started.  The beer still measures at 1.022 SG so it is sitting at 10.24%.  You would never guess that it's that high in alcohol.

• 3/19/16 - Tasting Notes - This beer had a great level of complexity after primary fermentation and it has gotten significantly more interesting with age.  I really like the coffee/chocolate/roast flavors and aroma along with the dark fruit character.  The Brett seems to be getting to be a more significant player in the flavor profile with some time in the bottle and it is creating some really nice aged beer sort of flavors.  Hops have fallen off but they aren't missed.  Will do another tasting of this beer next year around this time to see how further age treats it.

Lessons Learned:

1. I was reading about mash thickness while brewing.  From what I read a thinner mash can help ensure that there are fewer fermentable sugars in the wort.  I have been sticking with the 1.25 ratio of water to grain and raising the temperature to try to get some residual sugars left over (including for this batch).  I may have to try playing around with this a bit
2. I'm really leaning strongly towards putting together a new brew stand with a RIMS setup here in the near future.  I am getting very tired of only having one pot and having to lift stuff.  Also don't like the guessing game with the mash temp
3. I had a significant efficiency bump on this batch that I don't understand.  One theory is that the hot sparge water may have been more efficient about rinsing the sugar.  Another reason for a second large pot.
4. The warm summer basement temps have had a pretty strong influence on this beer.  It has somehow dropped 10 gravity points after having not moved at all for 5 months in a cold basement.  Vary interesting.  I'm wondering if it's wise to bottle this beer at 1.022 in the winter temps.  Am I setting myself up for gushers and bottlebombs?