Announcing Lutra™ Kveik, A Shockingly Clean Kveik

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OUR CUSTOMER IS OUR CATALYST. Brewing is a community, and our ability to pioneer owes itself to camaraderie. At the 2020 Ohio Craft Brewers Conference, one of our loyal customers gifted us cans of their helles lager they’d fermented with our Hornindal Blend (OYL-091). While we’d always recommended the strain, with its speed, high temperature tolerance, and fruity esters, for modern IPAs, this helles, fermented at 70°F, showed our Hornindal could produce a remarkable pseudo-lager. Taken aback by the beer’s clean characteristics, we brought it to the lab and ran a blind tasting with the rest of the team. Our suspicions were confirmed.

We thought perhaps there were individual strains within the Hornindal blend that could be isolated to provide the same clean fermentation results at normal kveik-level temperatures (90°F+). We began by isolating as many unique strains from the blend as possible. First, we struck the complete blend on Wallerstein Laboratory Nutrient (WLN) Agar to isolate as many colonies as possible [A]. WLN is a handy medium for identifying different strains within a blend because it contains a dye (bromocresol green) that is absorbed differently by different strains. Some strains accumulate the dye and become dark green, while others don’t take up the dye and become more cream colored. The colony’s shape and size can also help differentiate the strains. Some exhibit smooth borders while others have rough edges.

From there, we pulled 16 colonies from the first streak and re-struck them on WLN plates for further evaluation [B]. Then we isolated DNA from the individual strains in order to perform “interdelta analysis”. Put simply, there are repetitive DNA sequences that can vary in their number and location within the yeast genome. Consequently, when these sequences are amplified by PCR, the band pattern can vary from strain to strain and allow one to differentiate between strains that otherwise appear the same. 3 of the 16 colonies that were struck to WLN led to mixed light and dark colonies, indicating that they were not true isolates and were excluded.

Using these two analyses, we categorized strains that had identical band patterns and identical WLN traits as the same strain. For example, strains 6 and 9 reflect the same band patterns [C]. If two strains had the same band pattern but different WLN appearance, they were categorized as unique strains. Similarly, if two strains had an identical WLN appearance but different band patterns, they were categorized as unique strains. This approach allowed us to identify unique strains that may have been assumed to be identical to another strain if a single trait was relied up for differentiation. As a result, we identified 9 unique strains from the Hornindal blend [D].

Out of the 9 unique strains that were identified, one of them stood out as being the cleanest, most lager-like performer of the bunch in trial fermentations. To really test this strain in its ability to brew a pseudo-lager, we built a simple helles lager recipe and organized a tasting panel for a descriptive sensory analysis.

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Our tasting panel described the Helles brewed with the isolate as

  • Clean
  • Crisp
  • Dry
  • Grainy
  • Lemony Dough

The results confirmed our data from the lab analysis. What we discovered was this isolate strain maintained an ultra-clean profile when fermented at 68℉-95℉ and exhibited kveik level fermentation behavior creating an extremely versatile canvas for brewing a wide range of styles including American stouts, West Coast IPAs to pseudo-lagers. For the most lager-like profile, we suggest fermenting between 68℉-72℉.

Have any questions about Lutra? Hit us up at info@omegayeast.com.

Happy brewing!