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Snaewaert et al. also looked at the metabolic composition of finished beers in the three breweries. Glucose was completely gone from the samples, but substantial concentrations of maltose, maltotriose, maltotetraose, maltopentaose, and maltohexaose were still present. This contrasts with the relatively high glucose and fructose found in finished bottled versions of these beers, which indicates that the beers are back-sweetened with young beer or with residual sugar or even possibly just some form of sugar at bottling time <ref name="snauwaert"></ref>.
Overall the flavor of these beers was dominated by ethanol, lactic acid, acetic acid, ethyl acetate. Across the samples there was a presence of isoamyl alcohol (31-150mg/L) and isoamyl acetate (1.99-6 mg/L), and an absence of 2-phenyl ethanol and 2-phenylethyl acetate in both the matured beers and the bottles versions of those beers. Small amounts of propionic acid, isobutyric acid, ethyl hexanoate, and ethyl octanoate were found. Higher levels of ethyl acetate were found compared to the Martens et al. study, and no ethyl decanoate, which is a typical ester found in gueuze, was found. Just as the microbial populations of Brewery 2 differed from Breweries 1 and 3, so did it's overall metabolite content. Higher levels of acetic acid were found in Brewery 2, which was attributed to high levels of ''Acetobacter'' populations. Additionally, all three of the samples from Brewery 2 differed from each other as far as metabolic content, which was also attributed to the microbial population differences between each of Brewery 2's samples <ref name="snauwaert"></ref>.
==See Also==