This information is also found at my Water and Salts page.
Water makes up more than 90% of beer's total mass. At the same time, many homebrewers don't consider water an ingredient. Who knows, maybe your water will make great beer for you and the styles you like. However, for those of us who want to fine tune our brews, it is very useful to know how to adjust our water to fit the beer styles we make.
Avoid Chlorine in brewer’s water. It can ruin the flavor and aroma of your beer. Since municipalities use chlorine to provide the public with healthy clean water, it will need to be removed. This can be accomplished by adding campden tables, boiling the water, or running the water through a carbon filter.
Campden tables are easy to use and effective. Add 1 tablet to 5 gallons if you have very little chlorine in you water, or up to 1 tablet per gallon if you have a lot of chlorine. Add the tablets to your brewing water before mashing or adding anything to the water. I would give it a little time to work. Click here for an in depth discussion of the matter. Personally, I do not like adding anything extra to my beer. On the other hand, campden tables break down chlorine into products that yeast use for nutrients.
Boiling the water can evaporate the chlorine over time. The amount of time to boil is often quoted as 15 minutes. However, if some studies have shown that it can take up to 2 hours to boil off the cloramine (a chemical sometimes used by some municipalities to treat the water).
The best choice by far is to run your brewing water through a carbon filter. This is my choice. I have well water with a high iron count. Therefore, I have a chlorine injector, carbon filter, and water softener. I do not want the softened water in my brew because the softening process exchanges the ions I want with sodium which I do not want. I simply bypass the softener and voila, clean non-chlorinated water.
An under-the-sink carbon filter works as well. However, for those who love to build and create their own equipment, here is a DIY project.
If your water is clear and tastes good, chances are you can make good beer with it. If you are already making good beer and want to move to then next level, then continue to the Salts and Acids section.