The more I've learned about Kveik yeast, the more tempted I am to try pushing it to do new things. It's my understanding that Kveik is very tolerant of high gravity worts, low pitch rates, and of course high temperatures. My goal with this brew is to see if I can push it to produce a beer that is at or above 16% ABV. Although I did start with an award-winning barleywine recipe from the AHA web site, I've altered it so much here that it's no longer recognizable. (Update 7/11/2020: I based this goal on the limits of the Voss strain in its non-isolated form. Later, I learned that the Lallemand isolate version is limited to 12%, which I had no problem hitting.)
Some of the changes I made included raising the gravity significantly, adding demerara sugar in place of some of the malt to dry it out a little, using German Northern Brewer hops to bitter, and adding a flavor addition of Mandarina Bavaria and Bramling Cross late in the boil. I also used Pilsner malt extract to minimize the amount of grain I had to load into The Grainfather. I'm also swapping out the original yeast used (a British strain, I think) for Lallemand Voss Kveik. I'll be using Brewtan B to help limit oxidation, whirlfloc to try to clear it a bit (along with a beta glucan rest at 120F for the same reason), lots of yeast nutrient (which Kveik needs), and will be making sure it's well oxygenated before the yeast is pitched.
6 pounds Extra Light Pilsen DME
4.5 pounds of Viking Pale Ale malt
1 pound of Vienna malt
15 ounces of British Medium Crystal (55-75L)
12 ounces of Special B malt
12 ounces of Demerara Sugar (added at 60 min. mark of the boil)
0.66 ounces of German Northern Brewer hops @ 4.9% AA (60 min.)
1 ounce of Bramling Cross hops at 6.5% AA (10 min.)
1 ounce of German Mandarina Bavaria hops @ 9.2% AA (10 min.)
0.75 tsp. Alpha Amylase enzyme added during the mash to help conversion
1/8 tsp. Brewtan B in the mash water
1/4 tsp. Brewtan B in the boil (20 min.)
1/2 whirlfloc tablet in the boil
2 tsp. Yeast Nutrients
3.6 gallons of RO mash water treated with 0.7g baking soda, 1.5g calcium chloride, 0.5g Epsom Salt, 2.5g gypsum, 0.5g magnesium chloride)
1.5 gallons of RO sparge water, untreated (note: this was about a half gallon too much)
According to Brewfather, the beer should have the following qualities:
- Batch Size: 3 gallons (2.75 gallons actual)
- Original Gravity: 1.135 SG estimated (1.131 SG actual)
- Pre-boil Gravity: 1.046 SG estimated (1.110 SG actual)
- Final Gravity: 1.025 SG estimated
- IBUs: 55
- SRM: 26
- BU/GU: 0.40
- ABV: 16.7%
The mash schedule will be:
- Mash in at 120F for 20 minutes (beta glucan rest for clarity)
- Mash at 140F for 45 minutes (fermentability)
- Mash at 156F for 45 minutes
- Mash out at 168F
- Sparge with room temp water (1.5 gallons)
The boil schedule will be:
- 90 minutes: Add demerara sugar and dissolve well
- 60 minutes: Add German Northern Brewer
- 20 minutes: Add Brewtan B
- 15 minutes: Whirlfloc and Yeast Nutrients
- 10 minutes: Mandarina Bavaria and Bramling Cross
- 0 minutes: Chill to 86F (or as close as I can manage)
The fermentation plan will be:
- Attach a fermwrap heater to the fermenter and an Inkbird controller to maintain a minimum temperature of 86F in the fermenter. If the yeast free-rises above 86F that's fine, so long as it doesn't get above 104F... in which case I'd take steps to chill it down. I don't expect that to happen.
- Every 24 hours, swirl the fermenter to keep the yeast in suspension.
- If the yeast seems to be slowing down before final gravity is reached, add some more nutrient, possibly aerate the wort, and possibly pitch additional yeast.
Ideally, I would like this to be a nice. bright beer that ages until Christmas. Once fermentation is finished, I plan to dose it with gelatin finings and cold-crash it in my mini-fridge until it's clear, before bottling.
Brewing Notes and Observations
07/05/2020: I dissolved the DME in the mash water before adding the minerals and grain. I did this because I wanted the enzymes in the grain (and the alpha amylase I added) to break the long-chain sugars (in the DME and the grain) down for easy digestion by the Kveik. And since I'm planning a long boil, having the DME in early on will help caramelize the sugars. I'm expecting a complex, malty beer with lots of malt flavor, balanced out by a healthy dose of hops. I don't want it to come across as overly bitter, but enough to balance against the malt.
The sparge water calculation yielded much too much wort pre-boil. I ended up boiling for about 45 minutes to get the volume in the kettle down to where I originally wanted it to be, then started my 90 minute timer. When the boil was approaching its end, I filled my hydrometer sample tube by counter-flow-chilling some wort from the kettle. The hydrometer read 1.130, which is also what the Tilt Hydrometer read. Although this is lower than the 1.135 I was aiming for, it's plenty close enough. I'm hopeful that the addition of the amylase and the longer mash schedule will result in a very fermentable wort that ferments to a lower gravity than Brewfather is estimating.
Fermenter volume was only 2.75 gallons, and that included dumping the dregs from the kettle into the fermenter as well. I set the temperature control to 86F and pitched the half-packet of Voss Kveik yeast into the wort.
07/06/2020: The Kveik seems to be quite happy in its new home. Around 1am, it started showing signs of fermentation activity. Now, at 5:30pm, the gravity has dropped from 1.131 SG to 1.093 SG. Brewfather calls this 36% fermented (or rather 36% of the sugar they predict will ferment away is gone). The airlock was gurgling away happily when I last saw it.
07/07/2020: The yeast is continuing to do its job. It's currently brought the gravity down to 1.072 SG. I bumped the temperature control up another couple of degrees because it had dropped to around 84F, then later a couple more to get it above 86F.
07/08/2020: Temperature has been holding in the 89-91F range since yesterday. I'm going to bump it up into the Voss Kveik optimal range of 95-100F today to ensure that fermentation continues. Gravity is now reading 1.068 SG which represents 45% attenuation and an ABV of 10%. We are well on the way to the planned 16%+.
07/09/2020: Temperature has been increased to 95-97F. The gravity has dropped to 1.057 SG today, representing an ABV of 11.6%. Earlier in the day, I dosed the beer with Yeast Energizer to help it keep going and swirled the fermenter to help keep the yeast in suspension.
07/10/2020: Temperature has held between 95-97F. Gravity is down to 1.056 SG today with a single reading of 1.055 SG in there. ABV is currently estimated at 11.8%. Fermentation is definitely much slower now but hasn't stopped completely.
07/11/2020: According to Lallemand, their Voss isolate strain can handle up to 12% ABV. That seems to fit with what I'm seeing. The fermentation has been holding at a gravity of 1.055 SG. I've decided to cool the beer down to around 70F and pitch a package of CBC-1 yeast, which can handle a much higher gravity than the Voss strain seems to be able to take.
07/12/2020: 24 hours later and no fermentation activity. The CBC-1 and WLP099 didn't seem to come to life. Tonight I swirled the fermenter several times to stir up the yeast and release some CO2. I also added yeast nutrient and a whole package of champagne yeast. Hopefully some combination of CBC, WLP099, and champagne yeast will get rid of some of the remaining gravity (which has held at 1.057 SG for two days now).
07/13/2020: Gravity held at 1.057 overnight, in fact even rising as the beer cooled to 1.058 SG and holding there. After lunch, I added three drops of glucoamylase enzyme (which in past experience has really dried out beers that have stalled) and the rest of the WLP099 yeast vial. I'd added a lot of yeast nutrient the last couple of days, so I didn't add any more as I doubt the existing yeast made much use of it. I also swirled the fermenter vigorously after adding the yeast and enzyme so that those hopefully get better mixed in with the beer.
07/16/2020: The fermentation seems to have stalled the last few days. Attempts to revive it have not been successful, with gravity continuing to register in the 1.056-1.057 SG range for nearly a week now. Today I decided it was time to take a very last-ditch effort to restart fermentation. I sanitized my wine degasser, attached it to my drill, and degassed the beer while also vigorously swirling the yeast back into suspension. After doing that, I added yeast nutrient and some glucoamylase enzyme to break sugars down into the most-digestible form. For further "nudging" I moved the fermenter onto our screened-in back porch where the current temperature is about 87F. If this doesn't get the yeast going again, I am going to have to toss this batch - which will be a disappointment.
07/17/2020: Gravity has dropped by a point since yesterday. I'm remaining hopeful that the yeast will finish out the beer, but time will tell.
07/20/2020: Gravity is down to 1.052 SG.
07/21/2020: The gravity reading from the Tilt alternates between 1.052 and 1.051 SG, suggesting that the yeast are still working, albeit very slowly.
07/22/2020: The gravity is holding at 1.051 SG today.
07/23/2020: The gravity is reading 1.050 SG today, which represents 12.7% ABV.
07/24/2020: Gravity is still reading 1.050 SG today.
07/26/2020: Gravity is reading 1.047 SG today.
07/27/2020: Gravity is still reading 1.047 SG.
07/28/2020: I swirled the fermenter very vigorously. Since then, the gravity has been reading 1.048 SG. Hopefully this helped keep the yeast in suspension enough to continue dropping the gravity.
07/30/2020: Gravity is continuing to read 1.047 SG today (13.1% ABV).
08/02/2020: The gravity is still reading 1.047. Today, I dosed the beer with a little pure oxygen and placed a heat wrap around it to keep it at 85F or higher on a more consistent basis. Gravity showed as 1.045 SG later in the day.