As part of investigation into all-grain brewing, I looked for information on water quality here in Madison.
Data is available in the form of the city’s water report here. According to How to Brew by John Palmer, the most important properties of brewing water are Calcium (Ca+2), Magnesium (Mg+2), Bicarbonate (HCO3-1), Sulphate (SO4-2), Sodium (Na+) and Chloride (Cl–). Concentrations in the table below are in PPM (or mg/L, same thing).
| Substance | Madison, WI, USA | Pilsen, Czech Republic | Munich, Germany | Burton on Trent, UK |
| Calcium | 69 | 7 | 75 | 270 |
| Magnesium | 41 | 2 | 18 | 60 |
| Bicarbonate | 354* | 15 | 150 | 200 |
| Sulphate | 17 | 5 | 10 | 640 |
| Sodium | 7 | 2 | 2 | 30 |
| Chloride | 15 | 5 | 2 | 40 |
The data from other brewing cities is taken from here. Unfortunately there doesn’t seem to be data for bicarbonate for Madison in the report, but after some Googling I found this – for the west side of Madison, but probably close enough.
So – the bicarbonate level is really high; looking through posts on the forums I think for most beers reverse osmosis water with a gallon of tap water added for minerals is going to be the way to go.
