A few years back a customer brought me a beer that he said was fermented at 95F. I immediately thought of Belgian Saison, as that strain can ferment at high temperatures (90℉ +) but has a strong phenolic (spice/clove) character. Yet this beer was clean with some nice fruit esters, no phenolics.
What could this yeast be? He said it was a Norwegian strain called Kveik (which is just one of the Norwegian words for yeast). This type of yeast has been cultivated in Norway for years for it’s warm and fast fermentations with no off flavors (i.e. phenolic/clove/smoke). Lars Garshol has been writing about them in his blog and Omega Yeast worked with Lars to isolate some of these strains commercially. This has been a game changer for both homebrewers and breweries. Brewers can choose to make a beer with significantly less temperature control (or none at all depending on where you live). You need less energy to cool down your wort since you pitch at 95F, and for breweries especially, the warm ferment means fast turn around of beer.
Kveik isn’t meant to replace all of the conventional strains you might be used to using, they are just unique strains and each one has its own character. They are best used when you are trying to get your beer done quickly or have no fermentation temperature control. They can be used for a wide variety of styles which makes them ideal when you’re a homebrewer who might not have the space or cash for a temperature-controlled fermentation chamber. Every kveik offers something slightly different.
There are a few tips on having a successful brew using Kveik. Many of the beers that these strains were isolated from started as high gravity worts which means that not only did the wort have a lot of sugar but it also had a lot of nutrients, mainly Free Amino Nitrogen (FAN) which is naturally found in all malt wort. So if you are not making a high gravity beer, you’ll want to add some extra nutrients to your wort. A half tsp of Wyeast’s beer nutrient 15 minutes in the boil will work just fine.
Another thing we’ve noticed is that although these strains will work at lower temperature, they work best at warm temps. If the ferment gets too cool too soon the yeast may stall and not completely finish fermenting (attenuate). If this happens you can gently shake the fermenter and put it somewhere warm, this should get it started again. But the best bet is to pitch the yeast around 95F and try to keep it in a warm place.
Even though your beer should ferment to terminal gravity within a few days, it is still a good idea to let the beer sit a few extra days for maturation, allowing the yeast to metabolize flavors created during fermentation that you may not want.TLDR on Kveik:
- Low gravity beers need nutrient
- Fermentation temperatures should start high and stay high until fermentation is finished
- Let your beer condition even if it’s “done” fermenting
For even more information on Kveik check out our interview with Lance Shaner of Omega Yeast. Please do check out Lars Garshol’s site as well - he has been instrumental in bringing these amazing yeasts to the wider brewing community.
Looking to brew right now? Here are the kveik strains we’d recommend:
|Lutra||Lutra is shockingly clean with unrivaled speed when pitched at 90F (32C). The strain is perfect for brewing a refreshing pseudo-lager without the lead time of a lager. Also an excellent choice to make a fast hard seltzer. Although primary fermentation may be done within days, Lutra still needs some lagering (cold storage) time for the beer to clear. This can be done in the bottle after carbonation has been achieved. Available as both liquid and dry.||Lagers, Hard Seltzers|
|Voss||Excellent for IPA’s, Voss’s character changes little over its broad temperature range, with orange citrus notes. It is non-phenolic and pairs well with citrusy, fruity hops. Available as liquid or dry.||IPA, Pale|
|Hothead||A highly flocculant strain with an astoundingly wide temperature range and little change in flavor across the range. Clean enough for both American and English styles, it has a unique honey-like aroma with overripe mango. Complementary to modern, fruity hops. Non-phenolic and no noticeable fusels, even at higher temperatures.||IPA, Pale Ale, Pale English Ales|
|Hornindal||Hornindal produces an intense tropical flavor and aroma with notes of fresh pineapple, mango, and tangerine. Compliments fruit-forward hops as well as adding another dimension to beer made with traditional "C" hops. Warmer fermentation temperatures will increase the aromatic profile and fermentation speed.||IPA, Pale Ale, Barleywine|
|Espe||Originating from the village of Grodås in Norway, Espe offers the unique profile of lychee, pear, and tropical fruit cup. The strain bolsters the sweet aromatics of modern IPAs, but is versatile enough for your flagship pale ale or seasonal brew. Espe is most expressive when fermented at 90F+ (32C+), but still reveals its character at lower ale-pitching temperatures.||IPA, Pale Ale|