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Summers can be brutal for brewers who don't have fermentation temperature control. Once temperatures climb above the ideal 18-25 °C range for ales and above 12-15°C for lagers, yeast metabolism is up-regulated. This leads to the beer fermenting too quickly, churning out off-flavors (esters, fusels, diacetyl) and even stalling entirely if the wort gets too hot. As a general rule, fermenting your beer at temperatures too high for the particular yeast strain you're using is a fast track to making poor quality beer.
Many homebrewers often resort to cooling hacks like wet towels or cold water baths, as well as fermentation chambers and glycol chillers for the more serious home brewers out there. By using high temperature Kveik yeast strains you can completely avoid the need for cooling procedures and still make great beer. Originating from Norwegian farmhouse ales, Kveik strains love heat. In fact, they happily ferment at temperatures up to 40 °C without imparting off-flavours.
In practice this means you can brew a beer in the height of summer as-is. Kveik will blitz through the ferment quickly and cleanly, often finishing fermenting in 2-3 days. By choosing a Kveik strain, you turn your fermentation thermostat way up instead of nursing it in the cold. Kveik (pronounced “kvyke”) literally means 'yeast' in Norwegian. In old Norwegian farmhouse practice, each family kept their own mixed-culture yeast, dried it on wooden rings or staves, and passed it along through generations and between social circles.
Kveik yeasts evolved under very different conditions than modern lab yeast strains. These strains are pitched hot (28-40 °C) and ferment fast (often 1-2 days). These unique yeast strains are super unique and have genetic changes that make them suited for high temperature brewing. They accumulate protective compounds like trehalose to survive the high heat and use other genetic traits to produce minimal off flavours like phenols and fusel alcohols that would make normal beer fermented this hot undrinkable.
. Instead of fighting the Australian climate you can work with it, simply pitch your Kveik into warm to wort and let it run. At 30-35 °C or more, most Kveik strains ferment out in 3-5 days, although we've had beers finish fermentation in less than 24 hours! Compare that to the week or more for ales (or months for lagers). And you don’t even need to baby them to the same extent that you do for a traditional yeast strain as extreme temperature and fluctuations don't typically change the beer flavour to the same extent as traditional yeast strains .
The only real trick is to ensure you have space for a big krausen (the creamy yeast foam that sits on top of your fermenting beer), and ideally a blow-off tube. After the yeast flocculates, you can cold-crash if you want quick clarity, but most Kveik strains drop bright on their own when given enough time.
Kveik fermentations are usually highly attenuative so it's a good idea to select beer styles that work well with a dry finish or incorporate higher mash temps or unfermentable adjuncts into your recipe. Maltodextrin or lactose are good options if you're after a thicker body or sweeter finish respectively.
This higher attenuation means you can brew big IPAs, Imperial Stouts or barleywines in summer too. And because Kveiks are often phenolic-negative (lacking the enzymes for clove or smoke-like phenols), even warm ferments stay fairly clean, although this strain dependent. More on that in a moment.
Flavour-wise, there are many strains of Kveik yeast these days, all of which have different characteristics from a clean, crisp profile to funky farmhouse character or even fruity characteristics. As with all ferments if you'd like to promote more of the unique yeast character, fermenting on the warmer side will bring this out while slightly cooler will subdue it to some extent.
We stock a variety of different Kveik strains so you can find the right strain for the beer style your brewing.
Lutra is exceptionally clean and neutral. Almost like a lager yeast that can ferment between 20°C and 40°C. Omega describes it as “shockingly clean with unrivaled speed” at 32 °C, we would absolutely agree. It ferments like a champ at 20-35 °C and finishes dry (75-82% attenuation). This makes Lutra perfect for crisp pale ales or “pseudo-lagers” when you want minimal Kveik fruitiness. We find that Lutra is the only truly clean Kviek that's suitable for lager-style beers. We've also had great success using Lutra in high ABV barley wines and Imperial Stouts that have turned out awesome too!
Lutra is also a dried yeast variety meaning it stores super well in the fridge (usually a few years) and can be shipped across Australia hassle free!
This is the classic Voss strain from Sigmund Gjernes’s brewery in Voss, Norway. It has a huge temperature range (25-40 °C) and ferments extremely fast at the top end, full attenuation often in 2 or 3 days. Voss is noted for a fairly neutral flavor profile with just a hint of orange/citrus. We have found that it's not quite as neutral as an American ale yeast and definitely produces some Kveik funk and orange marmalade character but not so much that it's a dominating flavour like a Belgian ale yeast. Voss flocculates very well and can handle ~12% ABV, so it’s great for clear, hop-forward ales or farmhouse styles, or even high ABV IPA or imperial style beers. (Note: Mangrove Jack’s M12 Kveik is the same strain, just sold under a different label as far as we can tell). Voss tends to play pretty well with dry hopping and hop froward beer styles in general too. We've seen plenty of brewers produce successful IPA's, NEIPA's and other hoppy styles with this one.
Both Mangrove Jacks M12 Kveik and Lallemands Voss and dried yeast strains which means they also store well in the fridge and can be shipped across the country without issues.
Buy LalBrew Voss Kveik - Shop Now
Buy Mangrove Jack's M12 Kveik Voss - Shop Now
Hornindal is a big-flavor Kveik. Description notes tropical stone fruit, pineapple and dried fruit leather aromas. It’s the blend of strains from Hornindal, Norway, famous for producing juicy farmhouse ales. Hornindal can ferment at 32-35 °C (and above) with no noticeable fusels. In practice, Hornindal throws fruit esters at warm temps. If you want an intensely fruity ale, try a NEIPA or citrusy pale with Hornindal to boost the tropical notes. It also flocculates high and has ~13% ABV tolerance, so it can knock out big beers comfortably. We havent had hands on experience with this one yet as it hasn't been released in Australia but we'll update this post once we do!
Bergen is their take on a Norwegian farmhouse ale yeast. It loves 21–37 °C. At the cooler end of that range it’s fairly clean, but as you crank up the heat it builds an orange-peel ester profile with a pretty distinct of earthy spice and tartness. Use Bergen for farmhouse ales, IPAs or saisons when you want an earthy character with a hint of orange character. We find that the flavour of this strain actually tends to work pretty well as a stand in option for hot fermented English ales too, just ensure to mash higher so it has some body for these beers.
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Oslo is described as the “pseudo-lager” specialist. So far, our experience has been that this is not the case, we found Oslo relatively clean, but it definitely still carries through more flavour than Lutra Kviek, putting it more on par with a standard American ale yeast. We have also found that this particular Kviek strain doesn't accentuate hop character that well, even with large dry hop doses this strain tends to subdue the hop character. If you're after that super clean pseudo-lager character we'd opt for the Lutra instead.
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These strains cover the spectrum from neutral to funky. For a crisp lager, try Lutra. For citrusy fruit, pick Voss/M12 or Hornindal. For classic farmhouse character, Bergen is a great pick. If you're after a balanced pale try Oslo.
If the summer heat has been a barrier to your brewing, these high-octane yeasts are your solution. We stock all the above strains, so the next time it’s sweltering outside, crack open a pack, pitch, and enjoy cold beers in no time.
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