08.25.20
Lutra® is a recently-discovered hidden performer within the historic Hornindal blend. It was suspected to be the surprise star of a professional brewer’s Helles, brewed with the full Hornindal blend.
Capable of producing a clean canvas, Lutra® was isolated and analyzed by our brewing scientists.
Less ester-expressive than any other kveik we have encountered, Lutra retains the kveik ability to ferment favorably at very high temperatures relative to other European-origin strains, and therefore with unusual speed:
At the last Ohio Brewers Conference, a local brewer shared his German-style pilsner with us. Surprisingly, he had used Hornindal, fermented at 70°F. The result of his work was shockingly clean and refreshing — missing the signature, tropical, fruity complexity that is Hornindal’s usual calling card.
We wanted to give the strain capable of fermenting a wildly clean, lager-like canvas the opportunity to work alone.
The lab team systematically isolated Hornindal’s unique strains, looking for the kveik that had until now been talked-over by its more expressive peers, the strain responsible for fermenting a wildly clean, lager-like canvas at kveik temperatures.
Through a series of culture analyses, PhD microbiologist and Director of the Omega Yeast R&D department, Laura Burns, and her team found it, plucked it from its cooperative anonymity, and named it Lutra® Kveik (OYL-071) after a river otter (a nod to it’s easy going, lovable nature, and to it’s clean, refreshing (river) home).
Less ester-expressive than other kveik, Lutra has proved particularly advantageous in pseudo-lagers, West Coast IPAs and American stouts.
A colony’s shape and size can also help differentiate the strains. Some exhibit smooth borders while others have rough edges.
Sixteen apparent-unique colonies were observed when differentiating by this combination of color, colony shape or both.
SIXTEEN COLONIES BECOME THIRTEEN ISOLATES
These sixteen unique strains were then re-struck on two additional WLN plates to help verify they are unique isolates.
Three of the sixteen colonies that were struck led to mixed light and dark colonies that indicated that they were not true isolates and were excluded.
THIRTEEN BECOME NINE
A comparison of the DNA of each strain using interdelta analysis was needed next, to help categorize each strain with another point of comparison.
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, a band pattern emerges that can vary from strain to strain. The band pattern provides a fingerprint which adds another level of differentiation between strains.
USING BAND PATTERNING AND WLN TOGETHER
Strains that had identical band patterns and identical WLN traits were categorized as the same strain.
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 nine (9) unique strains in the Hornindal blend, of which Lutra was one. With test brewing we determined the performance of Lutra as advantageous for pseudo-lagering due to its clean canvas at high temperatures, and likely the strain that stole the show in the Ohio brewers’ Helles.