pH is measured at various points during the brewing process. This electrode is intended to measure the pH of the mash for the optimization of starch conversion. The enzymes required to convert the starch into sugar are pH-sensitive with an optimal pH range between 5.2 and 5.6 pH. Different compounds are used to adjust the pH including phosphoric acid, lactic acid, and gypsum.
Wort clarity and break formation are also affected by pH. Protein coagulation occurs during wort boiling, where the optimum pH is around 4.9, even though a common boil pH is 5.2. A pH that is too high will not only inhibit coagulation but also promote browning due to the interaction of amino acids and reducing sugars.
Hop utilization during the wort boil is also affected by pH. As pH increases, the solubility of hop resins increases. Unfortunately for hop lovers, a high pH also increases the release of tannins resulting in a harsher taste. Higher pH also favors elevated microbial activity.
As a living catalyst, yeast maintains a pH around 6.5 within its cells; however, the preference is to inhabit a more acidic environment. During the fermentation stage, the pH should be lower to accommodate the yeast and also to ensure microbial stability and consistent flavoring of the beer; an optimal pH range during fermentation is between pH 4.1 and 4.3.
This pH electrode can be used to measure the wort before and after boiling. It is important to note that if used after the boil that the wort be allowed to cool to below 80 oC (176 oF) in order to prevent damaging the sensitive glass.