13,703
edits
Changes
m
no edit summary
The general flavor profile of kveik yeast is ester-driven and non-phenolic, although a wide range of subtle differences can exist between strains. Kveik in its traditional form is usually a blend of closely related strains. The "Stranda" kveik was described as "lemon, nuts, grain, and straw" by Lars Marius Garshol. The "Hornindal kveik" with bacteria was described as "fruity, milky caramel, honey, and mushroom with a very unique aroma". The "Muri kveik" was described as "earthy on the nose, and fruity tasting with hints of rubber and sulfur and a thinner mouthfeel than the others" <ref name="kveik_testing"></ref>.
Kveik has adapted to being fermented at relatively warm temperatures without producing off-flavors (fusel alcohols, diacetyl, or acetaldehyde), usually in the range of 30-40°C (86-104°F), but also as high as 43°C (109°F). The beer is finished fermenting within a day or two at these warmer temperatures. Årset kveik has been fermented as low as 4°C (39°F), which produced a clean and drinkable beer with a fruity aroma. They have a high alcohol tolerance of around 13-16% ABV <ref name="garshol_preiss_mbaa">[https://www.mbaa.com/publications/tq/tqPastIssues/2018/Pages/TQ-55-4-1211-01.aspx How to Brew with Kveik. Lars Marius Garshol and Richard Preiss. MBAA Technical Quarterly, 2018 Q4.]</ref>. [http://www.omegayeast.com/ Omega Yeast Labs] describes their two isolates as being non-phenolic, fruity, and complimenting American citrus hops. They also note that the yeast has a very high temperature range (~68-98°F or ~20-37°C), attenuates high, tends to flocculate well, and also tends to ferment faster at the mid to high temperature ranges, while producing similar ester profiles throughout the entire temperature range. Other kveik cultures generally produce subdued aromas below 20°C (68°F); different kveik cultures react differently at different fermentation temperatures <ref name="garshol_preiss_mbaa" />.
Pitching rates for kveik are also one of the unique things about these cultures. In general, pitching at typical ale pitching rates produce subdued esters. In order to express the yeast fermentation profile more, kveik cultures are traditionally pitched at a very low rate, perhaps somewhere around the 1-2 million cells/mL for 15-20°P wort. Brewers should experiment with the pitching rates for a given kveik strain of mixed culture, and determine which pitching rates produce desirable results. Oxygen should be at least in the 5-8 ppm range, although 10-12 ppm might be beneficial. [[Kveik#Kveik_Ring.2FKveikstokk_and_Drying|Dried kveik cultures]] have a cell density of around 9-18 billion cells per gram of dried yeast (Fermentis has around 31 billion cells per gram by comparison), and so pitching as little as 10 grams of dried kveik into 100L of wort could be fine. Dried kveik is generally rehydrated in first runnings for about 2-4 hours before pitching into the main batch, with a [http://www.garshol.priv.no/blog/367.html yeast scream] being traditional to ward off evil spirits. Kveik cultures are heavily dependent on nutrients, and wort that is lower than 1.050 can benefit from doubling nutrient additions <ref name="garshol_preiss_mbaa" />.