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→Impact of Fermentation Temperature
Their results showed that there is a vast diversity in how temperature effects attenuation for different strains of ''B. bruxellensis''. In general, the cooler 15°C (59°F) fermentation temperature slowed the attenuation rate for most strains. The US-05 attenuated the most at both temperatures, with only one saison strain matching that attenuation level when fermented at 22.5°C (72.5°F). This same strain, which was isolated from a commercial USA saison beer, and the BSI Drei strains had fast attenuation rates that were comparative to the US-05 fermentation at both temperatures, while the other strains had lag times of 8-10 days at 15°C (59°F) or 2-4 days at 22.5°C (72.5°F) <ref name="Tyrawa_2019" />.
At 15°C (59°F), none of the ''Brettanomyces'' strains could match the US-05 attenuation, with most of them falling to around 50-25% less final attenuation after 28 days, and one of the wine strains and one of the USA saison strains fermented almost nothing at all. Still, this data showed that some beer strains of ''B. bruxellensis'' can ferment at lower temperatures . Interestingly, one of the wine strains was almost unaffected by the difference in fermentation temperature; it only lagged for a couple of days longer in the colder 15°C (59°F) fermentation temperature versus the warmer 22.5°C (72.5°F) fermentation temperature <ref name="Tyrawa_2019" />.
At 22.5°C (72.5°F), all of the ''Brettanomyces'' strains fermented much better, although their final attenuation numbers for some strains were significantly less than other strains and quite varied, with only one strain (the previously mentioned strain that was isolated from a commercial USA saison beer) attenuating at levels that matched the US-05 control. This indicates that most ''B. bruxelensis'' strains are not as efficient at fermenting wort by themselves as ''Saccharomyces cerevisiae'' ale strains <ref name="Tyrawa_2019" />.