Changes

The buffering capacity of the mash is higher than wort due to the grain material. This has a positive affect on the growth of lactic acid bacteria. Peyer et al. (2017) found a slight increase in cell growth of ''Lactobacillus'' when incubated in a soured mash versus when souring in wort. However, due to a much higher concentration of sugar content and buffering capacity of the sour mash versus plain wort, less lactic acid was actually produced. This study also found that sour mash beers have almost four times as much acetaldehyde as the co-fermented and kettle soured versions , although this was speculated to be caused by the oxidation of ethanol in the sour mash, which converts alcohol back into acetaldehyde <ref name="peyer_2017">[http://www.asbcnet.org/publications/journal/vol/2017/Pages/ASBCJ-2017-3861-01.aspx Sour Brewing: Impact of Lactobacillus amylovorus FST2.11 on Technological and Quality Attributes of Acid Beers. Lorenzo C. Peyer, Martin Zarnkow, Fritz Jacob, David P. Schutter, Elke K. Arendt. 2017.]</ref>.