January | 2021 | Medieval Mead and Beer

This is part 5 in a series covering the brewing of farmhouse ale during the Norsk Kornølfestival 2020.

Session 1: https://youtu.be/eTDX6fds7EU
Session 2: https://youtu.be/LNIbYj_J2QI

Saturday, October 10^th, the brewing world was treated to a special event: the Norsk Kornølfestival 2020. First happening in 2016, the festival quickly grew a fine reputation for the place to be for anyone interested in farmhouse brewing and the phenomenon of raw ales. In 2020, instead of canceling, the festival went virtual and for a whopping 12 hours anyone interested could follow the brewing of three different styles of farmhouse beer at three different farmhouse locations online.

During the 12 hours, three farmhouse ales were brewed using three slightly different processes. Hornindal brewed a raw ale, Stjørdal a 1-hour boil ale, and Voss brewed a 4-hour boil ale. Each group of brewers did things in a slightly different way: as they said themselves, where you have 50 brewers, you will find 50 different methods, and each brewer thinks their beer is the best! I spent a wonderful Saturday glued to the TV watching these different brewers chat about beer, while taking copious notes. The videos of the live festival are by now released on YouTube and to make navigating the two 6-hour sessions a little less overwhelming, I have annotated each process, step by step, as they appear in the videos (the times listed can be plus or minus a few seconds).

This is the final blogpost in the series and I left the best for last: kveik! This part covers the transcripts of the general questions regarding kveik, as well as the yeasty highlights during the brewing of the three farmhouse ales. I will also include a brief intro for the kveik-specific yeast presentations, as well as links to further resources, including the Farmhouse Kveik Registry, and research, historical background and practical techniques by Lars Marius Garshol of Larsblog and Mika Laitinen of Nordic Brewing.

The YouTube screen grabs are used with permission from the festival organizers.

Part 5: All about the KVEIK!

During downtime Lars Marius Garshol and Amund Polden Arnesen take questions from the live chat from the general public, including several about kveik.

2:43:20 (session 1) How does kveik react to aging, both barrel aging like Lambic, and bottle aging, or other types of aging like stainless steel, concrete etc?

Amund: “We have a brewery in Oslo that kind of does this so I will answer this question from our perspective. We have a house culture, which is a mix of three Hornindal kveiks at this moment, and we basically use this to make sour beer. The guys in Hornindal? They don’t want to make sour beer. We are basically going against tradition. And the reason why this works is that there are bacteria in some of these kveik cultures especially lactobacillus and we primary ferment to get the fruitiness from the yeast fermentation, and then we age to get the sourness. The longer you wait, especially in an oak barrel, the beer will sour. I have had Hornindal beer which was over a year old, from a bottle, that wasn’t sour. I guess there is a lot of influence on how you brew if the beer turns sour or not. But it is definitely possible to make sour beer with these kveiks, and it is also possible to make un-sour beer. This Lactobacillus seems quite sensitive to hops so we have done some whiskey wash brewing where we do not add hops and we measure the pH and it drops quite quickly, but when we use hops and make a hop tea or mash hop, it takes longer for the beer to go sour. It usually goes not as sour, but it goes sour. This is a complex question and it depends on which kveik you are using. If you are using a Voss kveik for instance, chances are less that it will go sour. But there is a lot of factors here, depending on how you brew, what you age it in, and how lucky you are, I guess.”

2:51:36 (session 1) What do we think about using kveik in mead and cider?

Lars Marius: “Kveik, you saw what Stig in Hornindal was preparing to do: he‘s got the first wort that came out of the mash and he wants to put the yeast in to that to grow. This yeast is really used to having lots of nutrients, when it grows but also when it ferments. Analysis by microbiologists shows that it has really high expectations for how much free amino nitrogen, as it is called, it needs, probably also other things. Experiences with fermenting mead and cider is that sometimes it works fine and there are no problems and other times it almost won’t start at all or it stops before you are finished fermenting. So, if you are going to ferment mead or cider with kveik – which you can do, it works just great – it is a really good idea to add yeast nutrient. And the same goes if your wort is not very strong. In Hornindal the beer is about 6.5% to 8.5% and in Voss, Sigmund Gjernes makes 8.5% but the guys in Dyrvedalen make 11-12% beer. This yeast is not used to wort that doesn’t have a lot of sugar and other nutrients in it. In fact, if you are fermenting relatively weak beer it may also be a good idea to add nutrients. There is not really any strong reason not to add nutrients, let’s put it that way.”

2:53:38 (session 1) Is there a difference between a boiled word and a raw wort, in that sense?

Lars Marius: “There probably is a difference, unfortunately, we don’t know that much about it. I don’t know if anybody has ever studied the chemical composition of raw wort. Obviously, it must have more protein, for example. Does it make a difference to the yeast? We don’t really know. We need some scientist to finally figure that one out!”

5:46:58 (session 1) What do you think about kveik being sold all over the world?

Stig: “It’s OK with me. I think if you should have the original kveik, you have to brew it in the original way. Otherwise, it would be weaker and weaker every time you use it. I think it is OK, I think the interest in it will be bigger when people can use it. People are interested in it all over the world, and then, I think we cannot just keep it for ourselves. I don’t think that is the right way. I think it is better people can try it, and if they are really interested maybe they will try [and brew] it original!”

5:48:17 (session 1) Do you think the commercial kveiks, the ones they sell from the labs, are different from the ones you are using in any way?

Stig: “I think they are, and will be more and more different because we don’t do it [brew] in conditions where we have control over everything. You have seen how we do it today and I guess there will always be, maybe, a flower or two in, we don’t have control [over that] sometimes. But I think that is the strength of the kveik, we don’t have the same temperature, not the same sweetness, I think that is why kveik can handle so many different worts with different sweetness and different temperatures.”

5:49:40 (session 1) How do you dry the yeast?

Stig: “We usually put it on paper, a baking sheet or whatever, and put it on a dry slightly warm place for two weeks or so and then it is [dry]. I don’t think it is smart to have it too hot, too long, because then I think you can kill it. But it has to be warm, and dry. And then, 14 days, three weeks, then I think you can freeze it.” Lars Marius: “Yes, you put it in the freezer in a plastic bag, right. This thing with it being too hot, in Hardanger, Jacob, he puts aluminum foil over one of these shoe racks that have heating in them to dry the shoes. And if he puts on [level] 1 then the yeast will dry quite quickly. And if he puts it on 2 then he kills the yeast. When we were brewing there for Norwegian TV he had put it on 2 and the beer didn’t ferment [both chuckle]. Stig: as I say, there are many different ways to do it.”

(random note) Was wort chilled?

Traditional farmhouse brewers in modern times use home-made modern immersion wort chillers and (home-made) milk container collar chillers. Metal milk containers were popular to use for wort, and as milk needed to be cooled down rapidly just like wort, its use and already available equipment lend itself well to the farmhouse brewing tradition. Perhaps earlier it was placed in cold stream. Whichever way, the faster the wort is cooled, the safer it will be for the yeast. Kveik is a fast and hot ferment, it will really quickly make alcohol and then beat the competition. At first, hot wort will real quickly drop in temperature, but the last wait is the longest. With the high pitching temperatures of kveik that last bit is quicker: the brewer doesn’t have to wait as long to pitch as with normal yeasts.

4:00 (session 2) How are pitching rates determined in traditional brews?

Lars Marius: “You saw how they did it, right? They just take a certain amount of [dried kveik] chips, or a certain amount of liquid kveik and add that. There isn’t any measurement or anything like that. Stig for example will do the “mariaue” [yeast starter; see session 1 at 5:23:36 – 5:36:06] and use that to check his yeast is fresh and so on. Sigmund, as I understood it, he usually looks at the yeast, he opens the jar and if there is a lot of CO2 and it seems like it is fresh, he will just use it. If not, he will make a starter. They kind of play it by ear, see how the yeast is doing and determine it that way. We don’t really measure very much. Sigmund will typically pitch half his jar for example, and then, if it does not start, he will pitch the other half, as well. Tests on under and over pitching have been done by Escarpment Labs. They did a poster presentation at one of the brewing conferences where they looked at this, and what they found was that the Voss and Hornindal kveiks give more aroma if you under pitch them and less aroma if you overpitch but they found that for some of the other kveiks that was not the case. That’s really quite interesting. There isn’t a single rule that works for all the kveiks, basically.”

Amund: “From testing at the brewery, we experienced that the temperature is more important than the pitching. Even when we were under pitching less than the Escarpment Lab recommendation, we saw that as long as we had the high enough temperature on a 1,000-liter batch it did not matter. The temperature turned out to be more important than the pitch rate, for us. This was with our house culture, which is a mix between three Hornindal kveiks. We ferment 1,000 liters without temperature control so we have to pitch at a lower temperature in the summer months and a higher temperature when winter becomes strong. The brewery is from 18°C in the winter to 23-24°C in the summer. Of course, there is a big of a longer lag phase before the fermentation vessel has enough temperature to rise by itself. If it is colder in the environment, we have to pitch higher to have more temperature [buffer] to go down on.”

Escarpment Labs on the impact of pitch rate on kveik ferments

5:04:05 (session 2) Have you ever tried to combine Brettanomyces yeast with the kveik?

Amund: “Yes, we do that quite often. The way it usually goes is that primary ferment with our house culture, which is Hornindal kveik based, and then we put it into oak barrels or oak tanks which contain Brettanomyces yeast among other stuff. And what we see is that, especially the fruity ester profiles that the kveik make, get pretty much picked apart by the Brettanomyces and you get a more familiar Brettanomyces [?]. It seems that these huge ester profiles that the kveiks are famous for don’t really survive Brettanomyces over time. In that way, it is not really recognizable as a kveik” [he gives more detail, as well on his Brewery].

5:25:10 (session 2) Hornindal kveik had bacteria, does that contribute to taste?

Lars Marius is not sure, there has not been any research in that area. There are specialists working with brewing bacteria, like Lactobacillus, but in isolation, not as a mix working together.

5:31:58 (session 2) What does Sigmund know about the history of the kveik he has?

Lars Marius: “He got kveik from a neighbor when he moved to the farm where he lives now and started brewing there. That kveik apparently came from Bordalen but then he mixed in kveik from the family farm Gjernes and at Gjernes they used to get the kveik from the farm Veka in Dyrvedalen (I don’t know exactly who lived there at Veka so that is a hole in my research, I’ll try to find that out later). It is interesting, what he said was kind of the summary to all of this, kveik has forever been traveling around, circulating from person to person.”

5:35:00 (session 2) Is there a limit to how long a raw ale can be stored, apart from the normal aging issues?

Lars Marius: “Many people have said that long-term storage of raw ale does not work, but he has stored raw ale for six months and it kept going getting better, slowly souring and funking up. At the festival, I think last year 2019, Ståle served us his beer he brewed for the festival the year before. It was perfectly fine, normal storage issues but otherwise just great. And then there was the home brewing competition […] there was only modern beers in the home brewing competition. But the locals knew I had written this book about Norwegian farmhouse ales so they asked me to say some words and, I could not help it, I had to tell them I felt it really weird they did not have any of their own beers, all they had were copies of foreign stuff. And then when I sat down, the guy next to me turned around and said, would you like to try some raw ale? He had this huge plastic canister with beer that was two years old and it was fine. Different but fine. What is the limit? I don’t know.”

5:38:06 (session 2) Were any of the beers in the [Kornol Festival] competition carbonated?
Lars Marius: Three were carbonated, one made third place, but other than that, no – generally no.

(random note) Is the Oslo strain a real kveik?
The Oslo strain is a single strain. It is isolated from a kveik house culture, by Bootleg Biology and has very clean flavors. It was isolated from the house culture at Eik & Tid (Amund’s brewery), and is genetically in t kveik family.

Brewing the farmhouse brews
During the Norsk Kornølfestival the volunteer brewers brewed three different farmhouse ales. Especially Stig Seljeset from Hornindal shared valuable practical information on how to work with kveik. It was interesting to observe how matter of fact the brewers treated their kveik, as well as with obvious reverence; clearly kveik has a deep connection with the Nordic farmhouse brewing culture.

Links to the blogposts of the farmhouse ales brewed during the Norsk Kornølfestival.

Stig Seljeset and friends brew a traditional Hornindal kornøl as part of the Norsk Kornølfestival 2020; October 26, 2020
Kjetil Dale and friends brew vossaøl as part of the Norsk Kornølfestival 2020; October 30, 2020
Roar Sandodden and friends brew a stjørdalsøl as part of the Norsk Kornølfestival 2020; October 27, 2020

Brew #1: Hornindal
Stig Seljeset and friends demonstrate the brewing of a traditional Hornindal kornøl.

1:33:17 (session 1) How many generations of Hornindal or Voss kveik can I cultivate before is unviable or produces off flavors? Can it be harvested indefinitely? Stig: “When we harvest the kveik we dry it and stick it in the freezer and then you can have it for… I don’t know… I have been using kveik that is twenty-five thirty years old. Which has been in the freezer. If you dry it well, I think it will stay for a very long time.”

Does it sometimes happen that you have a bad year with the beer and that you don’t use the kveik from that year? Stig: “I only take care of the kveik when I have good beer, because we have so plenty of it, and friends, we just harvest the kveik when we have good beer.”

2:19:34 – 2:42:21 (session 1) At the beginning of the lautering stage the brewer started a kveik bowl by drawing out some hot wort in a kveik bowl to cool it down. He uses a large glass bowl as it will be put near the fire to keep warm, no more than half full to leave room for expansion.

2:35:44 (session 1) About the pronunciation of kveik: is there a definitive pronunciation of kveik? From Norwegians alone I’ve heard “kveik, kvie-ke, kvy-kee.” Most UK and North American people have opted for “kvy-kee.” Basically, how do you pronounce kveik?

Stig: “We just say kweik (with a slight rounding of the v, almost but not quite like a w). Lars Marius: You have a slightly different pronunciation than I do as I am from the east side of the country, I say kwejk (more emphasis on the “ei,” almost like an “ej”). But I don’t know that an English speaker would even notice. Stig: I myself, my language is very much like the old people here in Hornindal were talking, so I think the way I pronounce it is like they did for seventy years ago.” (2:36:49 for a loud and clear pronunciation)

Lars Marius: “When there is a vowel after the final “k” that’s a grammatical inflection. People say “kveika”, but it means “the kveik”. So it’s easy to be fooled here.”

4:20:05 – 4:31:09 (session 1) Stig placed the kveik bowl near the fire, guided by experience, and moves it closer or further away depending on how he gauges the temperature. Hornindal shows a beautiful traditional beer bowl with the text “you are welcome to the beer” around the rim in which the dried kveik flakes are stored. When the kveik wort reaches 29°C, they usually look for between 28-32/34°C, the kveik flakes are shaken into this wort. A bit cooler does not matter too much right now, but when added to the beer wort it should be 30-32°C as then it would start to ferment quicker.

Kveik raises the temperatures several degrees after pitching, from 29°C to 42.5°C. Natural high krausen occurs at 42.5°C and kveik keeps fermenting quite vigorously for a while after high krausen. Ferment in a good insulated fermenter to try and maintain the high temperatures so they do not go down to quickly to support this vigorous ferment (this is what makes kveik ferment so fast).

5:23:36 – 5:36:06 (session 1) Hornindal is congratulating the yeast starter, regionally called the “mariaue,” as it has “really done a good job, it is all foamy.” The kveik starter is 32°C and they are ready to put it all in the “gil,” here meaning a fermenter. They normally have the fermenter in the basement as it is warmer there, but they found down there they have no video, so for the sake of the festival the “gil” is set up in the garage. The fermenter needed some insulation as otherwise the kveik would not be warm enough.

And then it is time for the Yeast Scream! [5:27:30]

“We have done the brewing, now it is up to the kveik to do the rest of the job. We have to wait 40 to 48 hours and then we will know how it is.”

Brew #1: Hornindal

Brew #2: stjørdalsøl

There is a traditional kveik ring hanging indoors, obviously used before and setting the stage nicely. Stjørdal saves kveik only from good beer, traditionally dried yeast was stored in bags, rings, sticks, but now it is stored in freezer where it stays good forever. The locals all switched to bakers yeast, a store bought yeast, as they live in a humid area close to the fjord and they find it hard to save yeast.

Read more on traditional Norwegian bakers yeast, often sold as a solid block wrapped in parchment paper, at Lars Marius Garshol’s blogpost “Does bread yeast exist?” (2020)

And then there is the “most important part of brewing”: the Yeast Scream! (4:31:40)

To quote Roar: “many dark forces wanting to destroy our beer, the peoples that dwells below. So, we don’t dare to… don’t do it. Ready? SCREAM!!!… and skål!”

Brew #2: Stjørdal

Brew #3: vossaøl
5:17:58 – 5:46:38 (session 2; with some sound issues) The yeast is kept as a slurry in a rubber-ring jar. He draws the yeast from the bottom of the fermenter and stores it in the cold cellar; with its stone walls and earth temperatures, he been able to repitch it for several brews. He pitches the whole jar into the three buckets – he does not think kveik can be over-pitched: “it’s kveik!”

But before pitching he first takes a sip of it, to make sure it is fresh.

Lars Marius: “Is it customary to do the kauking (yelling) here in Voss?” “No… we never do that in Voss…[giggle]” Brewer: “We don’t do it every time, but sometimes we do it, in secret, if we are alone: then we may scream some black metal tunes into the beer! [laughing] Makes the beer extra good, and evil!” Another: “And that is the purpose of the beer!”

5:43:08 (session 2) Black Metal yeast scream!
Can you make out what he tells the kveik?

Brew #3: Voss

But wait, there is more!
Presentations on Kveik

In the downtime between the three different brews, which could take from 6 to 12 hours depending on the recipe, the festival scheduled several talks and presentations. The following should give you a general idea of what was discussed, where to go to see the full talk, and how to download their PowerPoint presentations.

2:46:43 – 2:50:18 (session 1) Lars Marius Garshol talks about Looking for yeast in Telemark (see image).
He brought back samples but due to Covid they have not been tested yet, so it is not clear yet what type of yeast it is. Lars Marius has tracked down all of the farmhouse yeasts he had heard about, including their origin stories, but as of yet there is no progress on the analysis.

29:04 (session 2) Traditional beers as a source of new yeast biodiversity
Mohammed Tawfeeq is a student at the Kevin Verstrepen lab at the University of Leuven which published the Gallone 2016 paper, showing that brewer’s yeast is divided into two major genetic families, called Beer 1 and Beer 2. Tawfeeq discusses his project where he characterized and compared 26 different farmhouse yeast cultures of a total of 1250 strains to typical ale yeast strains. The fermentation was done in common industrial conditions and in kveik conditions. The fermentation performance, as well as its metabolites and the tolerance toward different stressors (temperature, ethanol, sugar and salt) were tested to investigate the diversity of the farmhouse yeasts. More.

Link to the PowerPoint presentation
Press <tawfeeq-2020> to open the PDF of his PowerPoint, or the <Last ned> button to download the PDF directly.

2:30:00 (session 2) Beyond Kveik: 3 Unexplored Hotspots for Heirloom Brewing Yeasts
Martin Thibault has been seeking out farmhouse brewers all over the world and writes about his experiences. He finds traditional farmhouse beer cultures thrive to this day, hiding in plain sight from the Western world. Over the years, Thibault has visited farmhouse brewers in Lithuania, Norway, Estonia, Finland, Peru, Bolivia, Bhutan, and Ethiopia. Although their ingredients and recipes vary from ours, one thing unites these three hotspots with Norway’s own deeply-rooted brewing culture: they each have unfathomable quantities of their own heirloom yeast blends. More.

Martin Thibault has a blog where he writes about farmhouse brewing (in French).

Talk by Martin Thibault

Link to the PowerPoint presentation
Press <martin-thibault-talk-2020> to open the PDF of his PowerPoint, or the <Last ned> button to download the PDF directly.

Further information on kveik
There are myriad websites, blogs and YouTube videos discussing the performance of kveik in modern beers and how to use it. For this blog I only listed those with direct links to traditional farmhouse brewing, which pretty much limited the playing field to the blogs of Lars Marius Garshol, Larsblog, and Mika Laitinen, Nordic Brewing. Garshol also wrote about kveik in his book Historical Brewing Techniques: the Lost Art of Farmhouse Brewing (2020) as did Mika Laitinen in his Viking Age Brew: The Craft of Brewing Sahti Farmhouse Ale (2019). If you would like to learn even more, the Facebook group Milk the Funk is a good source for mixed fermentations, especially their online resource Milk the Funk Wiki. If you would like to know more about traditional and historic brewing then the Facebook group Medieval Brewing would be for you.

Farmhouse yeast registry

“Traditional Norwegian Kveik Are a Genetically Distinct Group of Domesticated Saccharomyces cerevisiae Brewing Yeasts” by Richard Preiss, Caroline Tyrawa, Kristoffer Krogerus, Lars Marius Garshol and George van der Merwe. Microbiol., 12 September 2018

YouTube