#67 Koschei Imperial Stout

Eureka, this is by far the most insane batch I have ever made and probably the last post for this year. Plus a recipe brewed not so long ago like the ones I posted recently… Anyway, I am a big fan of Imperial Stouts and I am still working on some recipes to get myself a really great example of the Imperial Stout style. Sure I have made some really tasty examples in the past such as two versions of the legendary Rusalka Imperial Stout. I even did a re-brew of the Rusalka Imperial Stout and let a part of if mature on Islay Whisky soaked wood chips. I added the Whisky to get yet another flavor compound. Islay Whiskys are well-known for their peaty character. The distillers on Islay (a small Scottish island) use peat to dry the green malt. This gives the Whisky a very peaty, smokey and phenolic taste. You either love or hate it. And I really, really like this character in the Islay Whiskys. Luckily for me, I can get my hands on some Islay malt. The smokiness you get from this particular smoked malt is very distinct to the one you get from the normal Bamberg smoked malt (Weyermann Rauchmalz). The smoked malt from Bamberg has huge smoked ham character. The Whiskymalt adds a very subtle smokiness to your beer. And not the overpowering smoked ham character. I will certainly post the tasting notes of the Whisky soaked Imperial Stout in the future.

Back to the Koschei Imperial Stout. Instead of just going with some unique malts or any other unusual ingredients to improve the aroma and flavor profile of an Imperial Stout, I used a different approach: Higher alcohol content. Alcohol can influence a character of an Imperial Stout in many ways. If the alcohol is not boozy but well incorporated in a beer it can help to improve the whole character of a beer. I basically used the Rusalka Imperial Stout recipe and went from there. I first added additional base malts to increase the original gravity and then adjusted the roasted malts. My target original gravity was around 27°P without any additions of sugars. I wanted to get an all malt Imperial Stout here. However, the lower efficiency forced me to add some sugar to get to the target original gravity…

About the name Koschei. I keep naming all my Imperial Stouts after dark characters from the Slavic mythology. Further information about the Koschei character can be found on Wikipedia. Lets have a look how my recipe for the Koschei Imperial Stout looks like:

Recipe: Koschei Imperial Stout
Numbers: Volume [L] 51 (13.5 gal)
Original gravity 27.4°P
Terminal gravity 7°P
Color Around 230 EBC
ABV > 12% (v/v)
Grains: Pale malt (6.5 EBC) 19.6 kg
Wheat malt (4 EBC) 2.5 kg
Roasted barley (1150 EBC) 3.15 kg
Carafa 1(900 EBC) 3.15 kg
Cara Munich 2 (120 EBC) 1.1 kg
Brown sugar (0 EBC) 2 kg (added during primary fermentation)
Hops: Northern Brewer (10% AA) 134.8 g and boil for 90 min
Northern Brewer (10% AA) 103.7 g and boil for 30 min
Northern Brewer (10% AA) 50.8 g and boil for 15 min
East Kent Goldings (5.1% AA) 156.7 g and boil for 15 min
East Kent Goldings (5.1% AA) 233.1 g and boil for 3 min
Yeast: Wyeast’s #1086 Irish Ale
Water: Burgdorf Mash: 26 L (6.9 gal),
sparge: 20 L (10.6 gal) @78°C (172°F)
Rest: Mash in @65°C (149°F),
90 min @65°C (149°F),
10 min @ 78°C (172°F)
Boil: Total 90 min
Fermentation: Primary 11 days @20°C (68°F) in plastic fermenter
Secondary In Whisky oak barrel for 5 months
Maturation: Carbonation (CO2 vol) 1.5
Maturation time Months to years

Fig 1: Koschei mash

10/14/12: An insane brew day begins with milling roughly 30 kg of malts (66 lbs). I had to mash-in in three different kettles! I filled my 50 L kettle (13 gal) and two other kettles with a volume of approximately 20 L of mash (5.3 gal) each. This made my wonder how I sparge such a huge amount of mash later on. Anyway, I left the mash rest at 65°C (149°F) for 90 min. I chose a lower temperature range for the rest to decrease the body of the beer later on. After the 90 min rest, 10 min rest at 78°C.

I then transferred the whole mashes from the two smaller kettles in my lauter kettle (50 L, 13 gal) and sparged the first part of the mash and collected the runnings in a kettle. I stopped sparging as the kettle (25 L, 6.6 gal) was full (Fig 2). The color of the wort was already very, very black. I then emptied the lauter kettle and filled it up with the second part of the mash and collected the runnings until the 50 L kettle was full. I then went on collecting the runnings until half of another 25 L (6.6 gal) kettle was filled.

Fig 2: Koschei first runnings boiling

Once all the three parts of the worts were boiling, I added the hops according to the recipe above. I split the hops between the kettles based on the volumes.

Because I am very inquisitive, I could not stop to collect further runnings from the lautering kettle and measured the gravity. I was surprised, the original gravity was still at around 12°P (1.048). I therefore filled another kettle with the third runnings. I used these runnings for batch #68. Will post about this experiment in the future.

After the boiling time of 90 min was over, I cooled the wort down to approximately 22°C and pitched a huge yeast cake of Wyeast’s #1084 Irish Ale I had from a previous batch of Imperial Stout. The fermentation started after several hours already.

Fig 3: Filling a Whisky barrel with Koschei Imperial Stout

25/10/12: Racked the beer off the huge yeast cake directly into a small Whisky barrel (Fig 3). I recently bought a small barrel (50 L, 13.2 gal) which was custom-made for me. The wood for the barrel is from a real full size Whisky barrel. The wood is therefore not fresh anymore and soaked in Whisky. I had a huge smile on my face when I got the barrel and unwrapped it: The Whisky smell was insane. Unfortunately, the barrel was not filled with an Islay Whisky. So no peatiness… Anyway, I got the barrel just a day before and rinsed it with some water first and added a shot of Bunnahabhain’s Darach Ur Whisky (Bunnahabhain is an Islay distillery with the characteristic peatiness) to kill any kind of bad microorganisms in there. Next step, I flushed the barrel with carbon dioxide to displace any oxygen in the barrel.

Then added the fresh Koschei Imperial Stout. I even had to add another 10 L (2.6 gal) of a maturing Imperial Stout from another fermenter to fill the barrel. However, the barrel wasn’t filled up to the top after that as well. Adding water or anything else was no option since I do not want to dilute my Koschei Imperial Stout any further anyway. I keep my fingers crossed and hope no complications occur because of the small headspace in the barrel… Depending on how fast the wood and Whisky character are detectable in the beer, I might have to fill the barrel to the very top and leave the beer in there for several months.

Fig 4: Koschei Imperial Stout in Whisky barrel. Maturation in progress… Some sour beers in the back

11/01/12: Beer now one week in the barrel. Time for a first tasting. The beer has some very subtle chocolate, coffee as you would expect from an Imperial Stout. However, not very overpowering at this stage. Some alcohol was in the nose as well. What about the wood/Whisky? To be honest, I could not tell whether this beer matured in a Whisky barrel for a week or not. No wood or Whisky character in the nose. A first sip. And again, not a lot of wood barrel character. Just the normal stuff you would expect from a young Imperial Stout like chocolate, coffee, alcohol, bitterness. But not a lot of the Whisky and barrel. It seems the maturation will go on for some time. This gives me the opportunity to think about another batch to refill the barrel after the Imperial Stout…

22/12/12: The beer is now roughly two months in the barrel. Seriously I had to taste the beer from time to time and it is quite interesting to taste the changing character of the beer over time. The appearance is really dark and very oily. There is already a lot going on in the nose. I can detect lots of chocolate, coconut, vanilla and some alcohol as well. All in all a really nice nose already. What about the taste? Chocolate again, a hint of smoke, pepper, a decent bitterness and it finishes with a chocolate, coffee, bitter, roasted character. Maybe some cardboard in there as well… Warming sensation of the alcohol. The only thing that I am not really sure about is if the beer is oxidized. I am not sure if the cardboard taste originates from oxidation or from a different source. In addition, the beer is flat and it is hard to foresee how the carbonated version might taste like.

The beer is on the right track in my opinion. It seems that it the beer can handle some further maturation in the barrel. I am really looking forward to taste this beer in a couples of years in the bottle already… Stay tuned for further updates concerning this batch.

I am not sure if I post another post before Christmas or even before the end of this year. I therefore wish you all a Merry Christmas and happy holidays. I hope you can find some time to relax and enjoy the upcoming days with family and friends. Or find some time to brew… I will certainly be back with new posts in January and some really interesting stuff for sure. Cheers, Samuel


03/29/13: Bottled part of the batch to a carbonation level of 1.5 vol of carbon dioxide. Beer spent roughly 5 months in the Whisky barrel. Remaining shares of the beer mature in kegs for further uses.

12/29/13: Tasting notes published


#31 Dunkelweizen

Eureka, today about a recipe I designed myself and brewed three times already. The recipe below is for a relatively straight forward Dunkelweizen (dark wheat beer, BJCP category 15B). I like dark beers in general and decided to create a darker version of a wheat beer. No further introduction, let’s go through the recipe:

Recipe: Dunkelweizen
Numbers: Volume [L] 20 (5.3 gal)
Original gravity 14°P (1.056)
Terminal gravity 5.4°P (1.021)
Color Around 30 EBC
ABV 4.7%
Grains: Munich malt (14.5 EBC) 1.0 kg
Wheat malt dark (16 EBC) 2.6 kg
Pilsner malt (4 EBC) 1.0 kg
Cara Wheat (115 EBC) 0.3 kg
Carafa Typ 1 (900 EBC) 0.06 kg
Acidified malt (4 EBC) 0.15 kg
Hops: Hallertauer (8% AA) 12 g and boil for 90 min
Yeast: Wyeast’s #3068 Weihenstephan
Water: Burgdorf Mash: 3.4 L (0.66 gal),
sparge: 20 L (5.3 gal) @78°C (172°F)
Rest: Mash in @47°C (117°F)
20 min @45°C (113°F)
add acidified malt, 15 min @53°C (127°F)
30 min @63°C (145°F)
40 min @72°C (162°F)
10 min @ 78°C (172°F)
Boil: Total 90 min
Fermentation: Primary 7 days @20°C (68°F) in plastic fermenter
Secondary None
Maturation: Carbonation (CO2 vol) 3.5 with fresh wort
Maturation time 3-4 weeks

05/13/11: Brew day number 31. All went according to the protocol above. Crush all the grains as mentioned in the recipe but crush the acidified malt separately. Then mash in at 45°C (113°F) but not the acidified malt. This malt is added after the 20 min rest at 45°C (113°F). The reason for this is to prevent a lower mash pH during the ferulic acid rest at 45°C. For further information have a look at a previous post of mine #48 Dunkler Nachthimmel.

Fig 1: Dunkelweizen mash

Then do the next rests at the mentioned temperatures, then sparge and boil the wort for 90 min with the hop addition. This beer is not about hops and therefore only a small amount of hops is added.

Fig 2: Collecting the Dunkelweizen wort

After the boil fill 10% of the wort’s volume into clean, disinfected glass bottles. In my case 2 L (0.53 gal). This fresh wort is needed at bottling to get the right amount of carbonation. Store the fresh wort in a refrigerator. Cool down the rest of the wort to pitching temperature of about 20°C (68°F) and pitch healthy Wyeast’s #3068 Weihenstephan yeast or any other wheat yeast you want.

I bottled the beer directly after a primary fermentation of seven days. I used the fresh wort to get the right amount of carbonation (3.5 vol of carbon dioxide). And there are enough yeast cells in the fresh beer. So no need to add fresh yeast at bottling. Please check whether your bottles can handle such high carbonation levels! Otherwise, you will have a lot of bottle bombs…

I then leave the bottles at fermentation temperature for another week or two and then store the bottles in a refrigerator. The beer is ready to drink within three weeks after bottling.


Aroma: Lots of banana, some caramel notes and the typical wheat beer character. No sulphur. Very nice aroma. Makes you thirsty!

Appearance: Brown color, the yeast in suspension makes it cloudy. Three finger tan, frothy head with a lot of bubble rising to the top.

Flavor: Pretty much the same notes I could detect in the aroma. Banana in the front, some caramel character, hints of spicy, phenolic notes.

Mouthfeel: Light-medium body, lively carbonation. Finishes with a malty and fruity aftertaste. The light-medium body makes it a bit heavier than a normal, pale wheat beer. However, the higher body does not make it less enjoyable. It is still a very easy to drink beer.

Overall Impression: I really like this beer. It has all the characteristic aroma, flavor profile you would expect from a wheat beer. Plus some additional character from the darker malts such as caramel. I am pretty satisfied with this recipe and would not change anything.

#23P Single Wheat Experimental Batch (SWaSH)

Eureka, today’s post is about another SMaSH (single malt and single hop) experiment. The reason for doing this recipe was to find out how a single wheat malt beer would taste like and to find out whether it is possible to brew a 100% wheat beer in the first place. I therefore call this kind of beer SWaSH for single wheat and single hop. One problem with such a setup is the fact that wheat malt does not have husks as most of the barley malts. These husks are necessary for lautering with a perforated bottom to get a kind of filter bed. Without such husks one could imagine that the wheat malt plugs the perforated bottom and makes a lautering relatively hard or even impossible. However, I have no experience with a 100% wheat malt based beer and a perforated bottom. I chose to do a brew in a bag instead to circumvent the lautering with my perforated bottom. That’s basically the most exciting part abput this recipe:

Recipe: SWaSH
Numbers: Volume [L] 5 (1.32 gal)
Original gravity 12°P
Terminal gravity 4.8°P
Color Around 4 EBC
ABV 4%
Grains: Wheat malt (4 EBC) 1 kg
Hops: Tettnanger (4.2% AA) 3 g and boil for 60 min
Tettnanger (4.2% AA) 2.5 g and boil for 30 min
Yeast: Wyeast’s #3068 Weihenstephan
Water: Burgdorf Mash: 2.5 L (0.66 gal), sparge: 4 L (1.1 gal) @78°C (172°F)
Rest: Mash in @47°C (117°F), 45 min @45°C (113°F), 15 min @53°C (127°F), 30 min @63°C (145°F), 40 min @72°C (162°F), 10 min @ 78°C (172°F)
Boil: Total 60 min
Fermentation: Primary 5 days @20°C (68°F) in plastic fermenter
Secondary N/A
Maturation: Carbonation (CO2 vol) 4 with sugar addition (40 g sugar to 4.5 L beer)
Maturation time 14 days

02/26/2011: Brew day. I chose to do a small SWaSH batch with 1 kg of wheat malt and some Tettnanger hops. I then preheated the mash water up to 47°C and inserted the malt bag into the kettle and added the crushed wheat malt. I then did the rests as mentioned in the recipe and pulled the bag out after resting at 78°C for 10 min and washed the grains with the sparing water. By the way, the iodine test was negative. Boiled the wort for 60 min with the small hop additions and cooled the wort down to 20°C (68°F) and added 25 billion (2.5E10) yeast cells for 5 L of wort.

03/05/2011: Its bottling time. Five days after brew day I bottled the beer with some sugar to get a carbonation level of approximately 4.0 vol of carbon dioxide. I then left the bottles carbonate and mature for nearly 14 days at room temperature and then put the bottles in a refrigerator.

05/07/2011: The beer is now nearly two months in the bottles and its time for a tasting. I tasted the beer before but never did any tasting notes. I kind of forget to do tasting notes and when I do them most of the beers are already past their best-to-drink date…

Aroma: Lots of banana, no hop character and no malt character detectable. Smells like a traditional South German wheat beer.

Appearance: Pale yellow color, lots of carbon dioxide bubbles rise to the top and form a very creamy, white head. Very good head resistance. I added some of the yeast sediment to get the real wheat character.

Flavor: Not a lot is going on here. Banana again and some of the lightly sour, bread, grainy character of the wheat malt is detectable. And the yeast gives the beer the typical yeasty, doughy character.

Mouthfeel: Light body, lively carbonation. Rather short and sweet, malty aftertaste. Very refreshing.

Overall Impression: The beer is still fresh and very refreshing after some time in the bottle. Lots of the characteristic wheat beer character such as banana and the character you get from the wheat malt are present as well. Sure a well made beer. However, it is a bit boring…

It seems that a 100% wheat beer is possible to make and enough enzymes are present in the wheat malt for a complete mash conversion. What about the wheat malt? First of all, the beer tasted like expected. Rather one-dimensional and lots of the wheat malt comes through. Hops are in the background and some of the wheat yeast character comes through as well. That’s what I was going for in the first place with this experiment. At least I now know what the wheat malt can contribute to such a beer.

Comparing the flavor profile of this beer with other homemade wheat beers from the past and some commercial examples, going the extra mile with a 100% wheat malt beer does not seem to have a big impact on the beer. I therefore can’t see any advantages brewing a 100% wheat malt based beer compared to a wheat beer made with 50% wheat malt and 50% barley malt. Thanks for reading and commenting if you like and stay tuned!