Changes

Just like in other yeast species, temperature has a direct effect on the rate of fermentation for ''Brettanomyces''. The optimal fermentation rate temperature range for ''Brettanomyces'' is between 25-32°C (77-90°F). Fermentation rate is about half as slow at 20°C (68°F). ''Brettanomyces'' will still grow at temperatures as low as (and maybe lower than) 15°C (59°F) and will be much slower, however one study showed a slightly higher viability during the full time period of fermentation at 15°C as opposed to the optimal growth and fermentation temperature range of 20-32°C. At a temperature of 35°C (95°F), fermentation is greatly inhibited due to cell death. The primary byproducts of ''Brettanomyces'' fermentation, which are ethanol, acetic acid, and CO2, are produced both during growth but also during fermentation after growth has stopped. At the more optimal fermentation temperatures of 25-32°C, ethanol and acetic acid are produced faster from fermentation, but the amounts of ethanol and acetic acid produced from fermentation are not affected by temperature (i.e. higher temperatures do not produce more ethanol and acetic acid from the same amount of sugar, they are just produced faster at warmer temperatures because fermentation is faster) <ref name="Brandam_2008" />. The warmer temperature ranges that are ideal for ''Brettanomyces'' fermentation rates and growth rates may still produce unfavorable flavors such as higher alcohols, however this has not been analyzed as far as we know.