Abstract 111
The effect of beer pH on colloidal stability and stabilization – A review and recent findings
Tech. Q. Master Brew. Assoc. Am. 47 (2): 1-5, 2010
K.J. Siebert
pH has a pronounced effect on the amount of haze produced in both model systems and beer from the same amounts of haze-active (HA) protein and HA polyphenol. The largest haze intensity is seen slightly above pH 4 and varies slightly with alcohol content. This pH promotes removal of HA material during maturation, resulting in better beer colloidal stability. Fining with HA proteins (gelatin or isinglass) or HA polyphenols (e.g. tannic acid) is similarly affected by pH, with greatest effectiveness near pH 4.3. Factors that influence beer pH are reviewed for their effects on colloidal stability. Under low adsorbent dose conditions, both silica and PVPP are slightly less effective at the pH where protein binds polyphenols most strongly. This appears to be due to competition between stronger protein-polyphenol interaction and binding of an HA material to an adsorbent.
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