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There is a highly genetic diversity between strains of ''Brettanomyces'' species, both in a [http://www.diffen.com/difference/Genotype_vs_Phenotype genotypic and phenotypic] sense <ref name="Crauwels1">[http://link.springer.com/article/10.1007/s00253-015-6769-9 Comparative phenomics and targeted use of genomics reveals variation in carbon and nitrogen assimilation among different Brettanomyces bruxellensis strains. S. Crauwels, A. Van Assche, R. de Jonge, A. R. Borneman, C. Verreth, P. Troels, G. De Samblanx, K. Marchal, Y. Van de Peer, K. A. Willems, K. J. Verstrepen, C. D. Curtin, B. Lievens. 2015]</ref>. Not all species are capable of consuming the same types of sugars. For example, ''B. anomalus'' (aka claussenii) are generally able to ferment lactose, but ''B. bruxellensis'' is generally not. Different strains within the same species may not be able to ferment the same types of sugars <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1279884332039778/ Lance Shaner experiment comparing the growth of various ''Brettanomyces spp'' on different growth mediums. 04/07/2016.]</ref><ref name="ncyc_searchbrett">[https://catalogue.ncyc.co.uk/catalogsearch/result/?q=brettanomyces National Collection of Yeast Cultures. Search for ''Brettanomyces''. Retrieved 04/07/2016.]</ref>. For example, some strains are not able to ferment maltose (often ''B. anomalus'' strains), which is almost half the sugar content of wort <ref>[https://eurekabrewing.wordpress.com/tag/sugar/ "Sugar composition of wort". Eureka Brewing Blog. Jan 13, 2015. Retrieved 04/07/2016.]</ref>. Such strains would not be a good choice for [[100%25_Brettanomyces_Fermentation|100% ''Brettanomyces'' fermentation]].
The ability of a given ''Brettanomyces'' strain to ferment different types of sugars might be at least partially linked to its source of isolation. For example, a strain of ''B. bruxellensis'' isolated from a soft drink could not ferment the disaccharides maltose, turanose, or the trisaccharide melezitose, whereas all of the other ''B. bruxellensis'' strains isolated from beer and wine could ferment these disaccharides/trisaccharide. The beer strains, however, were unable to ferment cellobiose or gentiobiose, as well as arbutin and methyl-glucoside. The wine strains were able to ferment these disaccharides, perhaps because they were adapted to the environment in which they were isolated from (wine barrels). Further studies are needed to see if this is a trend throughout the species <ref name="Crauwels1"></ref>. A study by Tyrawa et al. from [[Escarpment Labs]] agreed that wine isolated strains fermented cellobiose while strains isolated from beer did not <ref name="Tyrawa_2017">[https://www.facebook.com/groups/MilkTheFunk/1285391944822350/ "Funky can be Great: Brettanomyces bruxellensis Beer Fermentations" (poster for study). Caroline Tyrawa, Richard Preiss, and George van der Merwe. 2017.] </ref>.
Currently, research into how well ''Brettanomyces'' strains ferment the trisaccharide maltotriose has not been explored much by science, however, one study found that ''B. custersianus'' can ferment maltotriose. Another study found that all 7 strains of ''B. bruxellensis'' tested could ferment maltotriose, but not the trisaccharide raffinose. More investigation into this possibility is needed <ref>[http://www.asbcnet.org/events/archives/2015Meeting/proceedings/Pages/54.aspx Determination of sugar metabolism profiles of non-traditional yeasts in the Saccharomyces and Brettanomyces families. J. D. Cook, W. A. DEUTSCHMAN. ASBC Proceeding. 2015.]</ref><ref name="Crauwels1"></ref>.
Just like in other yeast species, the 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. The growth rate at 15°C, while still slowly active, varies from strain to strain with some strains growing very poorly <ref name="Tyrawa_2017" />. 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 <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1555689637792578/ MTF conversation with Richard Preiss of Escarpment Labs. 01/20/2017.]</ref>.
The below table is an example of the variety of sugar types that different strains/species of ''Brettanomyces'' banked at the [https://catalogue.ncyc.co.uk National Collection of Yeast Cultures] can ferment under semi-aerobic fermentation and aerobic growth (the '''semi-aerobic''' fermentation value is probably more useful for brewers since oxygen availability is limited during fermentation in normal brewing practices):