Changes

The pH of boiling wort influences how well proteins are precipitated out, with a pH of about 5.2 being ideal for this mechanism. At a pH lower than 5.0, these proteins gain negative charges, and at a higher pH they gain positive charges, making them resistant to settling out during boiling. Boiling a low pH wort that has been acidified by the fermentation of ''Lactobacillus'', therefore does not effectively precipitate out haze-forming proteins. However, haze forming polyphenols, which are also required for haze formation, are greatly reduced by an unknown mechanism during kettle souring, which can potentially leads lead to good clarity in the final beer regardless of the protein level (although other factors might still lead to a hazy beer) <ref name="Peyer_2017" />. Additionally, some strains lactic acid bacteria are known to cause haze as a side effect of their lactic acid fermentation.