The flat out, most basic rule of brewing water: If you won't drink the water, you won't drink the beer. If your water is deplorable, invest in a reverse osmosis system to strip it or buy water from a reliable source. The later sections teach how elements in brewing water affect flavor. Hoppy or dark beer lovers, learn how to use gypsum and calcium chloride to improve those beers.

With decent tap water, your main concern is chlorine. Even if you can't taste or smell it, all municipal water is disinfected, and you must eliminate the disinfectant before introducing the malt.

Using Tap Water: Getting Rid of the Chlorine

Sanitation prevents dangerous bacteria, mold, and fungus from the faucet. Before water reaches your home, the local water supplier doses it with numerous chemicals, including chlorine. While the odor and the taste are objectionable, a small amount stops drinking water from killing you. Today, most city systems have moved away from unstable chlorine to the stable and odorless chloramine.

Disinfected water can't be used for brewing without a little magic. Malt contains aromatic compounds called phenols. Normally, they form pleasant aromas associated with beer. Combined with chlorine, they become potent, medicinal-smelling chlorophenols. New brewers often forget the chlorine problem, while veterans can easily smell and diagnose the cause.

Chlorine is a snap to remove. It wants out and back to a gaseous state. That's why you can smell it so readily. To dechlorinate your water, either let it sit overnight or boil and cool.

Chloramine proves trickier. Since it's naturally liquid, it won't outgas and it survives boiling. You have several options. Activated carbon water filters are a common solution. Designed for light home usage, filter pitchers and add-on water faucets are not practical. Use an undersink or whole-house model to supply your water. Add hose barbs to the input and output and attach it to an RV water hose for outdoor usage. You must run slowly — under a half-gallon per minute — to ensure removal. Since the first stages are carbon, reverse osmosis systems work well.

Sodium or potassium metabisulfite, wine sanitizers, effectively tackle chloramine. Shops carry either powdered meta or the tablet form, camp-den. To drive off the chloramine, use one-quarter teaspoon of powder or one crushed tablet to clear twenty gallons of water. Stir and dissolve the powder into your water and wait five to ten minutes for the chloramine to react.

Buying Your Water

If you have truly awful water that no amount of filtration will fix, you can always buy seven or eight gallons of dechlorinated water. You want that extra water on hand to deal with evaporation, absorption, and accidents.

Skip over the mineral waters and the distilled water except when brewing pilsners. Distilled water contains virtually no minerals. Minerals are needed to accomplish or encourage some brewing reactions. If you use these options, read ahead for advice on adding minerals to the blank slate.

Water machines outside the corner store provide a cheaper option. You can choose your filtration types. Using a machine means trusting it's been well maintained. Buy your water from a dedicated water store instead.