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Spontaneous Fermentation

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Biogenic Amines
Loret et al (2005) examined the levels of biogenic amines in Belgian beers, including lagers, traditional ales, bottle conditioned ales, and spontaneously fermented beer (presumably lambic). They found that spontaneously fermented beers, which were 42 samples out of the total 297 samples and from 10 different breweries, generally contained the most biogenic amines, namely tyramine (associated with hypertension), histamine (associated with hypotension), and cadaverine. However, not all of these breweries produced higher levels of amines, suggesting that processing in some breweries is limiting the biogenic amine production (this process was not identified in the Loret et al study, but the process is likely to be the lowering of the wort pH to 4.5 to limit the enterobacteria phase). For example, 6 of the spontaneous fermentation breweries had levels of histamine as an average between 20-45 mg/l, and levels of tyamine between 30-60 mg/l, which is higher than the upper limit that is generally considered to be safe for consumers (this upper limit was stated as 10 mg/l by Loret et al.). The other 4 breweries had levels of histamine and tyramine between 0-20 mg/L, as an average. Interestingly, they also found that a small number of ales and bottle conditioned ales, 21 out of 220 samples, also had levels of tyamine above the upper limit of 10 mg/l. None of the lagers sampled had biogenic amines above 10 mg/l <ref name="loret_2005" />. Another study in Portugal measured biogenic amines in 5 Portuguese craft beers (4 ales and 1 lager; no mixed fermentation or sour beers) and reported that the total biogenic amine content was less than 10 mg/l for all of the beers <ref>[https://www.mdpi.com/1424-8220/23/1/343 Gil, R.L.; Amorim, C.M.P.G.; Amorim, H.G.; Montenegro, M.d.C.B.S.M.; Araújo, A.N. Influence of Brewing Process on the Profile of Biogenic Amines in Craft Beers. Sensors 2023, 23, 343. https://doi.org/10.3390/s23010343.]</ref>.
De Roos et al. (2018) measured biogenic amines over the fermentation lifespan of Belgian lambic beers that were pre-acidified to a pH of 4.5 before being cooled in a coolship and spontaneously fermented. They found that the initial wort had low concentrations of some biogenic amines, such as agmatine (9 mg/l), putrescine (8 mg/l), and cadaverine (3 mg/l). In one cask, the agmatine remained stable while in the second cask the agmatine declined to zero during the maturation phase, and then slightly increased to less than 5 mg/l. Cadaverine was produced during the first three weeks of fermentation and remained steady throughout the fermentation process at about 30 mg/l. Histamine was produced during the acidification phase by ''Pediococcus damnosus'' between 3 and 9 months and ended up at around 15 mg/l. Tyramine had final concentrations of around 30-40 mg/l and was formed either during the acidification phase (6 months) or the late maturation phase (18-24 months), potentially by ''P. damnosus'' or some other LAB that was at too low of a population to detect, or maybe as a result of autolysis of dead yeast cells. 2-Phenylethylamine and tryptamine were never found in the lambic beers <ref name="Roos_2018_2" />. A second study by the same group of researchers in 2024 confirmed that ''P. damnosus'' was responsible for producing histamine in lambic samples that were tested at one brewery; the total biogenic amines remained below the regulatory levels deemed safe for consumption in Europe <ref name="Roosa_2024" />.
The biogenic amines content of spontaneously fermented beer that is not acidified before fermentation is not likely to be high enough to cause serious physical harm. Large amounts of beer must be consumed before advisable limits are reached. However, the additive effect of different amines consumed with a large amount of beer might cause health related reactions in some people. See [http://suigenerisbrewing.com/index.php/2019/01/22/biogenic-amines/ "Fact or Fiction – Biogenic Amines in Beer" by Dr. Bryan Heit; an analysis of biogenic amines in spontaneously fermented beer and associated health concerns] for more information.

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