The concept of visualising how Mash pH settles at an equilibrium, based on the Gen II proton balance approach, has led to the creation of a spreadsheet presenting a graphical illustration of Mash pH vs. the Water Carbonate and Malt Buffer systems. During development it was also found that a more focussed illustration of Water Carbonate Alkalinity and Sparge Water Acidification could be realised.

The spreadsheet that accompanies this report is intended specifically as an aid to understanding these fundamental aspects of brewing chemistry and not as an actual brewing water calculator. It is hoped that the graphical illustration approach can aid in understanding how variations to the inputs affect what is actually happening in the liquor & mash, and why pH settles where it does, without it being necessary to work through all of the supporting calculations. However, details are provided in the report and below the graphs in the spreadsheet for anyone who wishes to investigate further. 

A review of how homebrew mash pH estimation has developed through the period from 2000 to 2025 is presented, including relationships between malt characterisations and pH calculations implemented across the spreadsheet and website calculators evaluated. Comparison between the Gen I and Gen II mash pH models offers an insight into physical validity, particularly with respect to grist pH buffer values.

Analysis of a common dataset by each of the calculators provides an example of the potential range of pH estimates that may be experienced.