Soft Water Sources
What about brewing beers like pilsner? You need soft water. Some sources of soft water include:
Rainwater/Snow Melt — For the most part, fresh snow and rainwater are soft waters. Generally they carry a light mineral load, roughly like Pilsen water. Have your rainwater tested before use and don't use without boiling.
Distilled Water — One of the few legal uses of a home still is to produce clean water. Readily available with other bottled water, distilled water is as pure as water gets. Because of the lack of any minerals, salt additions provide character and needed mash catalysts.
Reverse Osmosis — Slow and ponderous, RO systems are carbon filtration on steroids. Produces water almost as clean as distillation. Plan to start collecting water days ahead of time for your brew depending on your system's production rate. Flush the filters routinely to keep them effective. Treat like distilled water.
All-grain brewers desiring a more thorough explanation of water issues, check out John Palmer's How to Brew. The first revision copy is freely available online.
Both recipes that follow depend on certain water profiles. Boho the Hobo is a Bohemian pilsner that needs low-mineral-content water à la Pilsen. Hop Chameleon IPA, on the other hand, wants an extra kick in the pants from the sulfate. Prove to yourself the value of appropriate water additions by switching things up and making a sulfate-filled Boho the Hobo or a soft-water Chameleon.