Get the Most from Kveik Yeast
It has been nine years since Lars Marius Garshol introduced the world outside of its homeland in Norway to kveik yeast. During this time there has been a great deal of interest in these truly unique yeasts. They are now commercially available from a variety of yeast suppliers like Omega, Lallemand, Imperial, White Labs, Escarpment Labs, and others. Many homebrewers I have spoken with have jumped on the kveik train and enjoyed the ride.
What’s not to like? These yeasts offer clean fermentations with little need for temperature control, making fermentation really easy for low-tech homebrewers. Anecdotally, the commercial brewing world seems not to have embraced the use of kveik as much. Not to say there aren’t breweries who have done a couple batches with it, and even a few who ferment the majority of their beers with various kveik strains, but it is still fairly rare to find a beer on tap that was made with a kveik yeast. My guess is they are there, but no one is talking about them — of course most commercial beers do not list the yeast they use in fermenting their beers. Maybe we have all had many more kveik beers than we think.
I first used kveik to ferment a batch of beer in October 2019. At the time, I knew very little about these yeasts other than they were known to ferment quickly at very high temperatures, and with little concern about pitch rates; all of this supposedly came with no off-flavors like fusel alcohols. I was getting ready to pour at the Mendocino County Homebrew Festival in less than a week when I decided to experiment with kveik. If it didn’t work, I still had another beer ready to pour.
I had read that Hornindal kveik produced fruity esters when underpitched and fermented best at higher temperatures (up to 100 °F/38 °C), which would be perfect for a fruited kettle sour I had in mind. I propagated my Omega Hornindal Kveik (OYL-091), calculated my pitch to be approximately 70% of the recommended, added a bunch of yeast nutrients, set my temperature control to 95 °F (35 °C), and a new beer was underway.
Three days later, the power at my Mendocino home went out due to the Kincaid fire in Northern California. When I checked my gravity, I had 78.9% attenuation in three days. But with no easy way to refrigerate a keg, I had no choice but to bottle the beer. A couple of weeks later, when carbonation was complete, I had a fabulous blueberry kettle sour, was intrigued by this new yeast discovery, and was sure I would be using Norwegian yeast more often in the future.
The big “ah ha!” for me is the fermentation speed of these incredible yeasts. Most kveik aficionados will wax on eloquently, without much encouragement, about how they fully fermented out this or that beer in just two days. But we all know that sometimes our fermentations are smooth and predictable, and sometimes they are not. Less predictable fermentations require more patience on the part of the brewer, and thus, longer times. Whether your current fermentation is fast or slow, the overall turnaround time is significantly reduced by using kveik. The average time from brew day to serving carbonated beers from a kegerator for my kveik-fermented homebrews is around 7 days, cutting a full week off beers using traditional strains. This means that where I previously had brewed every four weeks, I brew every three weeks when using these Norwegian yeasts. This production increase was never intended; it is simply an added benefit of faster average fermentations.
Another advantage of these incredible yeast strains is their amazing temperature tolerance that requires no temperature control, even for those brewing in the desert. On a related note, an added benefit because it can tolerate much higher temperatures than conventional yeasts, is that cooling it down to yeast pitching temperature is much quicker and requires less water. I normally cool my kveik beers to around 100 °F (38 °C), transfer to the fermenter, pitch my yeast, and oxygenate. Since the yeast normally starts very fast it is not uncommon for the beer to show activity before I am finished cleaning up from the brew day. This is very different from other commercial yeast strains that need to be closer to 70 °F (21 °C) when transferred to the fermenter and commonly take close to a day to start.
With about 50 brews using nine different kveik strains under my belt, what follows in this article is a step-by-step explanation of how I go about using these unique yeasts, from propagating, harvesting, drying, and pitching. I hope after reading this, your imagination will take hold and you will also want to explore all that kveik has to offer.
Propagating and Pitch Rages
I use BeerSmith software to calculate my yeast pitches. In the past, I have confirmed my numbers using Brewer’s Friend.
I started out with approximately 225 billion yeast cells in an Omega pouch. With a 1.6-L starter and 4.4 oz. (125 g) of dried malt extract, I can safely assume that what I am ending up with is approximately 400 billion cells. When I dry this and get it into flaked form, I have 8 g of flakes. Numerous experiments and propagations have led me to what I refer to as “Drew’s Fuzzy Math,” which is that 2 g of dried kveik yeast = 100 billion cells.
I am a farmhouse brewer at heart. I live in a cerebral space where I try not to overthink things and trust the process. It might be due to being 50% Finnish, but it is more than likely just my artistic leanings and pragmatic nature. I always have believed there is a hard way and an easy way to do things. I now lean into the easy ways to get what I want out of my creative processes. Beer is one of these creative processes.
As I stated earlier, kveik doesn’t seem to mind being underpitched. This is true to such a degree that there was one experiment of Viking lore that I just had to try, which was the “One tsp. Kveik Experiment.” The idea here is that you could fully ferment out 5.25 gallons (20 L) of an 8% ABV beer with just 1 tsp. of slurry. I tried it in July 2021 using Omega HotHead® (OYL-057) on my “One Eye Rye” — an 8% ABV rye ale.
I started with 2 g of Omega HotHead® dried flakes (approximately 100 billion cells as per Drew’s Fuzzy Math). I made a 1.4-L starter with 4.7 oz. (133 g) of dried malt extract (for a starter gravity of 1.036). My BeerSmith calculator determined that this would yield approximately 300 b cells. I pitched 1 tsp. of this slurry into my beer and dried another tsp. to see the corresponding weight. I then dried the remaining slurry. Here’s what I got:
• 1 tsp. of dried slurry = 0.7 g
• The remaining dried slurry = 5.7 g
• 1 tsp. slurry used = 0.7 g
• Total = 7.1 g of dried flakes total from my 1.4-L starter.
So, approximately 300 g total / 7.1 g of flakes = approximately 43 billion cells per gram (not far off from Drew’s Fuzzy Math of 50 billion cells per gram).
This translates to approximately 30 billion cells in 1 tsp. of slurry (0.7 x 43 b = 30 b).
This beer started out slowly (as I expected), but in less than a day it achieved normal “kveik-like” activity. The 1 tsp. pitch translates to about 10% of the recommended pitch — and it still fermented out the beer in just one week with over 80% overall attenuation. So fermentation took about twice as long but still finished similarly to pitching at the recommended rate.
Harvesting – Top or bottom
A great resource for a lot of information on different strains of kveik is the Farmhouse Yeast Registry (www.garshol.priv.no/download/farmhouse/registry-versions/2023-04-20.html). Lars Marius Garshol has done incredible work over the past decade or so promoting and distributing information about these yeasts. This registry offers detailed information about where strains come from and how they like to be harvested. There is something called genetic drift that can happen where the yeast can adapt over generations to top cropping. Lance Shaner, Co-Owner of Omega Yeast Labs, described it like this: “Most ale strains can be top cropped to some degree if you catch them at the right time and are equipped to crop them. We haven’t specifically tried with kveik, but it’s not unheard of for there to be genetic drift that can be ‘captured’ if you continually top crop from generation to generation.”
So, even if your yeast is specifically listed as a “bottom crop” yeast, it can adapt to top cropping over time. I knew nothing of this when I started my Norwegian yeast journey but now have many strains that have adapted to the way I crop.
I do not have a conical fermenter, so I do not have the option of doing a yeast dump out of a bottom valve. I do have an open top on my fermenter, which makes it easy to do a top crop. (Those of you using carboy fermenters are going to have to explore creative ways to harvest yeast post-fermentation.) I top crop on the first or second day of fermentation when I have a thick kraüsen. The top crop yeast is cleaner and usually has a lot more viable yeast cells than the yeast drawn from a bottom crop. I top crop all of my kveik yeast beers.
I simply scrape off as much as I can (my understanding is you can’t over harvest), put it in a sanitized mason jar, and place it in the fridge. (Be sure to leave the lid loose so CO2 can escape in case it decides to get active.) The slurry will separate with the wort on top and the yeast at the bottom. I will top crop every two hours or so and usually harvest as many as four times.
Drying
In Norwegian countries it is not uncommon for brewers to dry their yeast on linen, wooden logs, or wooden rings that they hang on the wall to dry when done with the brew day. When they brew the next time, they simply drop the ring into the cooled wort. They have also been known to break off pieces of yeast. I recently saw a video where the brewer used his kveik ring for a starter. Kveik has been dried and stored in this fashion for a very long time. Kveik is unlike many conventional yeasts in that it tolerates this treatment.
To dry, I first discard as much of the liquid as possible and then pour the slurry onto a cookie sheet covered in parchment paper. From here it is simple to dry it out on a very low setting in the oven or my preferred method; a seed mat with a temperature controller set at 100 °F (38 °C) in a couple of hours. Note that while I do this regularly with great success with my kveik strains, I do not recommend it with other yeasts that are more finicky. I store the flakes in vials in the refrigerator or freeze them for longer-term storage after labeling the vials (shown in the image at top of this story).
Generations
I am still using my original pitch of Omega Hornindal that I started with over four years ago. I didn’t keep accurate records back then, but by my estimate this yeast is now in its 20th generation. In Norway the yeast is stored and reused multiple times; as long as it behaves normally and ferments fully, they keep using it. If something goes wrong, they get a fresh pitch from a neighbor and continue the process.
Nutrients and Oxygenation
Kveik yeasts are very oxygen- and nutrient-dependent. This may sound strange as historically, farmhouse brewers weren’t adding nutrients to their brews to help aid the kveik they fermented with. Shaner puts it like this: “Historically, kveik were used to ferment high-gravity, 100% barley malt worts, so they were domesticated in a very high-nutrient environment. It wasn’t necessary for the farmhouse brewers to add nutrients,” he said.
Given their nutrient dependence, I use three times the manufacturer’s recommendation (which is given for a traditional Saccharomyces cerevisiae strain) and make sure the beers are heavily oxygenated. I also believe the yeast works best when it is active at the time of the pitch. I have cold crashed it in the fridge and then pitched, but I would recommend pitching an active starter. (As a side note, I always make starters for my beers, even though building up a huge population of kveik isn’t necessary to successfully ferment a beer to dryness. The way I view it, starters offer added assurance that my yeast is viable at the time of pitching. I also always start with a blow- off tube, as clogged airlocks can get messy and these fermentations really take off.) Active yeast at the time of the pitch makes for faster startups and more predictable fermentations.
My four-year journey with kveik yeast has been a fascinating exploration of experimentation, adaptability, and the pursuit of unique flavors in brewing. From my initial foray into brewing with Hornindal kveik for a blueberry kettle sour, to the subsequent 48 beers I have made with kveik yeast, the experience has been marked by the durability, incredible fermentation speed, and temperature tolerance of these remarkable strains. And who doesn’t like free yeast?
Kveik Yeasts I’ve Used
Though this list is just a fraction of the kveik strains available, I thought it would be useful to offer some more insight on the strains I am familiar with in my own brewing. Following are descriptions and data points from yeast labs and the National Collection of Yeast Cultures (NCYC), as well as my firsthand insight on each strain.
Omega Hornindal (OYL-091)
NCYC 4051 — Recommended
Harvest: Top
Hornindal is the original blend Omega received directly from Lars Marius Garshol. Hornindal offers fruity esters that enhance the flavor and aroma of hops. Ferments well at 90+ °F (32+ °C).
• Flocculation: High
• Attenuation: 75–82%
• Temperature Range: 72–98 °F (22–37 °C)
• Alcohol Tolerance: 16% ABV
• Non-phenolic
My take: I have used this strain predominantly in fruited beers due to the ester production, but I am sure it would work with a wide variety of beer styles. I did use it once in a Bourbon barrel stout and got over 84% attenuation (way too high for my taste.) This is the oldest strain in my archive and is now around 20 generations old (2½ years old in flaked form).
Omega HotHead® (OYL-057) / Stranda
NCYC 4021 — Harvest: Top
HotHead® is Norwegian in origin — from the Stranda kveik. When Lars submitted Stranda to the NCYC, they only had a single colony grown up. In other words, Stranda/Hothead® is and always has been a single strain from the time it was obtained by Lars.
This isolate has a uniquely pleasant fruitiness and an absurdly wide fermentation range, and ferments clean across the entire range. It maintains a stable ester profile, and is great for hoppy American ales.
• Flocculation: Medium-High
• Attenuation: 75–85%
• Temperature Range: 70–98 °F (22–37 °C)
• Alcohol Tolerance: 11% ABV
• Non-phenolic
My take: HotHead® is my go-to kveik strain for IPA and DIPA. It ferments out fully and is very neutral.
Omega Lutra® (OYL-071)
(Available in liquid and dry form)
Isolated from Omega’s Hornindal Kveik (OYL-091) culture, Lutra® is shockingly clean with unrivaled speed when pitched at 90 °F (32 °C). The strain is perfect for brewing an even more neutral and refreshing pseudo-lager at its lower temperatures, without the lead time of other lager yeast.
• Flocculation: Medium-High
• Attenuation: 75–82%
• Temperature Range: 68–95 °F (20–35 °C)
• Alcohol Tolerance: 15% ABV
• Non-phenolic
My take: I started using Lutra® in May 2021 mostly for IPAs and DIPAs, but I have also used it in three stouts. I love and trust Hothead® (OYL-057), but this strain worked so well I just kept using it. In September 2023, I used it in a cold IPA and fermented out the beer successfully at the lowest recommended temperature (68 °F/20 °C). Neutral at all temperatures.
Yeaster Bunny Tormodgarden
NCYC 4171 — Harvest: Bottom
Tormodgarden yeast came from Straumsdalen, near Skodje. This yeast was originally found in the 16th century but was probably mixed at some point. The strain is very versatile and can ferment a wide range of beer types.
On the hot side, it will produce tropical, citrus/blood orange-like flavors. It can also be used to make lager-like beer on the cooler end of recommended fermentation temperature range.
• Flocculation: Medium-High
• Attenuation: 70–80%
• Temperature Range: 59–95 °F (15–35 °C)
• Alcohol Tolerance: Very High
• Non-phenolic
My take: I have used this in a variety of beers including porters, brown ales, and English ales. I got my original pitch from a European supplier in 2020, and have been using it ever since.
Omega Voss (OYL-061)
NCYC 3995 — Harvest: Bottom
A Norwegian kveik directly from the Gjernes farmstead. Like the mango-honey profile of Hothead® (OYL-057), Voss kveik’s orange-citrus notes are relatively clean and pair well with citrusy, fruity hops. Ester intensity and fermentation speed take off at higher temperatures. No noticeable fusels, even at higher temperatures.
• Flocculation: Medium
• Attenuation: 75–82%
• Temperature Range: 68–98 °F (20–37 °C)
• Alcohol Tolerance: 12% ABV
• Non-phenolic
My take: This is the strain that many homebrewers start out using and is available from numerous suppliers. I had it for quite some time before I gave it a try, mostly because I had so many other yeasts to use. Some brewers have noted a spiciness that was not to their liking. I will be using it more in the future to see what it does relative to the other strains I use. (This strain adapted well to top cropping.)
Yeaster Bunny Ebergarden
NCYC 4224 — Harvest: Top
From Stordal in Norway. Produces a very tropical fruit ester profile. This is an excellent culture to pair with late- addition and whirlpool hopping. Has anecdotal ability for hop biotransformation. This culture also accentuates hop bitterness.
• Flocculation: Medium-High
• Attenuation: 75–80%
• Temperature Range: 68–95 °F (20–35 °C)
• Alcohol Tolerance: 16%
My take: I have only used this yeast a couple of times in the last two years. I have always perceived it as being much like Tormodgarden. I have more experimentation to do with this strain.
Granvin (via Dustin Carver – Milk the Funk)
Harvest: Bottom
Orange-like with a slight acidic tinge, this culture would be perfect for hoppy IPAs or sours.
• Flocculation: Medium-High
• Attenuation: Up to 80%
• Temperature Range: 68–98 °F (20–35 °C)
• Alcohol Tolerance: High
My take: I like to use this yeast in DIPAs as well as beers that I have brewed using spices and herbs.
Yeaster Bunny Simonaitis – Landrace
NCYC 4207 — Harvest: Top
This yeast highlights tropical fruit, guava, and orange peel as it mixes with hints of unique herbal and spicy flavors. Lactobacillus is present and will contribute some acidity. This yeast is technically NOT a kveik strain, though it behaves like one by handling high temperatures and high-gravity wort.
• Flocculation: Medium-High
• Attenuation: High
• Temperature Range: 68–95 °F (20–35 °C)
• Alcohol Tolerance: 15%
• Phenolic positive
My take: I have only made two or three beers using this yeast. I have found the Lacto to add very little to the acidity.
Kveik Yeastery EitrHeim K14
NCYC 4284 — Harvest: Top or bottom
This strain of kveik is pretty different from the other “typical” farmhouse strains. The profile is ripe pear, plum, raisin, prune, and honey, as well as a little black pepper and saison character. Eitrheim kveik is a very versatile strain that can be used in a variety of beer styles from IPAs and stouts to traditional farmhouse styles.
• Flocculation: Medium
• Attenuation: 75–80%
• Temperature Range: 64–107 °F (18–42 °C)”
• Alcohol Tolerance: 12%
My take: I’ve only made one beer with this yeast and need to do more experiments.
KVEIK RECIPES
Aussie-Style DIPA
(5 gallons/19 L, all-grain)
OG = 1.074 FG = 1.014
IBU = 65 SRM = 6 ABV = 8%
This dip-hopped double IPA is one of the most unusual flavor profiles I have ever made. The dip hop mix produces flavors very much like white wine.
Ingredients
12 lbs. (5.4 kg) Pilsner malt
1 lb. (0.45kg) Maris Otter pale malt
1 lb. (0.45kg) caramel malt (20 °L)
1 lb. (0.45kg) flaked oats
1 lb. (0.45kg) white wheat malt
3.5 AAU CTZ hops (60 min.) (0.25 oz./7 g at 15% alpha acids)
3.3 AAU Chinook hops (60 min.) (0.25 oz./7 g at 13% alpha acids)
5.5 AAU Centennial hops (60 min.) (0.5 oz./14 g at 11% alpha acids)
2 oz. (56 g) Enigma® hops (dip hop)
2 oz. (56 g) Galaxy® hops (dip hop)
1 oz. (28 g) Citra® hops (dip hop)
3 oz. (84 g) Citra® hops (dry hop)
1 Whirlfloc tablet (15 min.)
1.5 tsp. Wyeast yeast nutrient (15 min.)
Omega Lutra® Kveik (OYL-071) or your favorite kveik yeast strain
3⁄4 cup corn sugar (if priming)
Step by step
I shoot for a mash pH of 5.4 and use a “hoppy lite” water profile. Mash in at 148 °F (64 °C) and hold for 45 minutes. Sparge and draw off 7.5 gallons (28 L) to the boil kettle. Boil for 60 minutes, adding the boil hops at the start of the boil. Add Whirlfloc and yeast nutrient in the last 15 minutes of the boil. Cool the wort to 180 °F (82 °C). Put the dip-hop additions into a muslin bag and place in the bottom of your fermenter. Cover the hops with just enough wort to submerge the hops and seal the fermenter. Allow the dip hops to sit in this liquid for one hour.
Cool the remaining wort down to at least 100 °F (38 °C) and transfer to the fermenter. Pitch yeast and ferment anywhere around 90 °F (32 °C). When fermentation is complete, bottle condition or keg and force carbonate.
Partial mash option: Reduce the Pilsner malt to 2 lbs. (0.9 kg) and add 6.3 lbs. (2.9 kg) of light liquid malt extract. Pour grains into a large muslin bag (or two separate bags, being sure they are not packed too tight) and mash the grains in 3.5 gallons (13 L) water at 160 °F (71 °C) for 30 minutes or until conversion is complete. Pull the grains from the kettle and rinse them with 1 gallon (3.8 L) of water at 170 °F (77 °C). Turn off the heat and stir in the malt extract. Stir until completely dissolved then turn on heat and top brew kettle to 6 gallons (23 L). Bring wort to a boil. Follow the remainder of the all-grain recipe instructions.
Smocadh (Bamberg-style rauchbier)
(5 gallons/19 L, all-grain)
OG = 1.068 FG = 1.014
IBU = 24 SRM = 18 ABV = 7.1%
This rauchbier recipe is courtesy of my brewing partner, Fernando López Angulo. The smoked malt adds a smoky complexity without overpowering the other flavors. While Fernando uses a smoke gun and a variety of tinctures and oils to dial in his smoke profile, this recipe is a good starting point. If you are new to brewing smoked beer, experimentation may be needed to dial in the smoke level for your particular palate. Due to the large percentage of smoked malt, this recipe does not translate well to extract-based brewing.
Ingredients
7.3 lbs. (3.3 kg) Weyermann Beech Smoked Barley malt
3 lbs. (1.3 kg) Munich malt
1 lb. (0.45 kg) Dingemans Special B® malt
1 lb. (0.45 kg) Weyermann Caramunich® Type II malt
0.5 lb. (0.23 kg) aromatic malt
0.5 lb. (0.23 kg) dextrin malt
0.5 lb. (0.23 kg) Simpsons Golden Naked Oats
0.5 lb. (0.23 kg) lactose
6 AAU Chinook hops (30 min.) (0.5 oz./14 g at 12% alpha acids)
4 AAU Centennial hops (15 min.) (0.5 oz./14 g at 8% alpha acids)
3.5 AAU Challenger hops (5 min.) (0.5 oz./14 g at 7% alpha acids)
1 Whirlfloc tablet (15 min.)
1.5 tsp. Wyeast yeast nutrient (15 min.)
Omega Lutra® Kveik (OYL-071) or your favorite kveik yeast strain
3⁄4 cup corn sugar (if priming)
Step by step
Shoot for a mash pH of 5.4 and use a balanced water profile. Mash in at 150 °F (66 °C) and hold for 30 minutes. Sparge and draw off 7.5 gallons (28 L) to the boil kettle.
Boil for 30 minutes, adding the hops at the beginning of the boil. Add Whirlfloc and yeast nutrient in the last 15 minutes of the boil. Cool the remaining wort down to at least 100 °F (38 °C) and transfer to the fermenter. Pitch yeast and ferment anywhere around 90 °F (32 °C). When fermentation is complete, bottle condition or keg and force carbonate.
