When brewing beer, certain styles are partially characterized by the water quality. Since beer is some 90% water, it’s composition can weigh heavily on the output. As well certain styles have come to be popular or even viable because of historical local ground-water conditions; particular English bitter institutions such as Bass are that way because of the super-hard water of Burton-on-Trent … Czech pilsners aren’t the same unless they’re devoid of minerals, as the groundwater of Pilzen is.
Thus, it’s useful to get an anlysis of ones ground water if you’re trying to brew certain styles; this may be posted on-line if we were in Palo Alto or San Francisco, but the Winooski water dept. has some catching up to do.
In any case, this is as of 2003, I believe, so it should still be basically valid for a few years:
- Calcium as CaCO3 (Calcium Carbonate): 45 ppm
- Chloride: 17 ppm
- Iron: < 0.01 pm
- Manganese: 0.007-0.012 ppm
- Sodium: 7.5 ppm
- Potassium: 1.31 ppm
- Sulfate: 15 ppm
- Silica: 1.4 ppm
- Silicon: 0.67 ppm