There is more to most water than two molecules of hydrogen and a molecule of oxygen. In most municipal water supplies, whether from aquifer or reservoir, you will have both natural minerals and manmade chemicals that are added to protect consumers from bacteria. Some brewers, such as Greg Noonan, find the local water supply unsatisfactory for their beer styles and feel the need to treat it. Others, like Scott Schwartz, take a more “hands-off” approach to his water.


Greg Noonan is the owner of Vermont Pub and Brewery in Burlington. In his book, New Brewing Lager Beer (Brewers Publications, 1996) he dedicates an entire 40-page chapter to water treatment.

At Vermont Pub and Brewery we employ an activated carbon “taste and odor” filter to remove the chlorine. It isn’t the most necessary of steps, since, as most homebrewers know, heating the water in preparation for brewing drives off chlorine. The mineral makeup is another story. The mineral makeup of most surface water supplies changes seasonally. Once we have a great recipe we are particularly concerned about replicating it accurately. The mineral content of the water affects that, so we monitor and treat the water according to its seasonal character.

Moreover, when we began brewing at Vermont Pub and Brewery 18 years ago, our water was very soft. However, in the intervening time our own “great lake” Champlain has been invaded by zebra mussels. When the little suckers die, their shells disintegrate into calcium carbonate. Our water supply has become much more carbonate, and therefor more alkaline. As Jim Koch of Sam Adams pointed out to me years ago, alkalinity produces dull-flavored beers.

Depending on the beer, we overcome the alkalinity by adding food-grade lactic acid or making up a partial sour-mash and adding that to the mash tun. Otherwise our water has a pretty low mineral content, so we generally add mineral salts to suit the beer style that we are brewing that day. We test our water at least monthly for alkalinity, hardness and calcium. We then plug those numbers into a spreadsheet that we developed to accurately and consistently turn water into the brewing liquor that we feel suits the particular beer we’re brewing (a copy of my spreadsheet can be found at byo.com.)

At Vermont Pub & Brewery we are conscious of beer styles, so we do treat our brewing liquor to suit each style that we brew. We want to emphasize the mineral character that complements a particular style. As an example, the only appreciable difference between a Dortmunder lager and a Bohemian lager is the mineral character of the Dortmunder — so in particular instances liquor character is essential to the beer style.

All brewing minerals add a mineral or salty flavor to beer, but each has a different flavor effect. The general rule in brewing to add gypsum (calcium sulfate) to British-style beers is a good one, especially if the beer is heavily hopped. Hoppy beers sometimes have an unpleasant soapy flavor. Calcium sulfate eliminates soapy flavors and accentuates a clean, piquant hop bitterness.

Magnesium sulfate is also common in English water sources, and has a similar effect in brewing. However, I don’t recommend using it because the salt is “diuretic.” That means it is dehydrating. So unless, for some bizarre reason, you like to pee a lot and wake up desiccated the next day, avoid or at least take it easy on the epsom salts (magnesum sulfate).

Chlorides generally don’t complement bitter beers. In moderation, sodium chloride does accentuate caramel flavors in malty beer, although we prefer to add calcium chloride because the sodium ion is harsher and in excess can harm the yeast.

We don’t add minerals for most lagers, Dortmunders being the notable exception. The Dortmund style requires moderate calcium sulphate and sodium chloride contributions to achieve its distinctive mineral character. We add calcium sulfate to bring the brewing liquor for our IPA up to 750 mg/L of hardness, and most other English ales up to 350–

500 mg/L. For Irish and Scottish ales our hardness target is lower, with more emphasis on the chloride content.

My feeling is that if you only have really hard water available to you, then brew hoppy English style ales or Dortmund-like lagers. Otherwise, your only real option is to buy purified  water for brewing malty beers. On the other hand, if you are blessed with a soft water supply, your options are wide open. You can brew lagers and malty beers with the soft water and add gypsum for English and hoppy ales.

Inexpensive freshwater test kits are readily available from aquarium supply shops for measuring the mineral content of water, so it isn’t a very difficult regimen for any homebrewer to replicate. You only need pH papers and hardness and alkalinity test kits. The calculations required to use that information in replicating classic brewing water profiles aren’t rocket science, although using a spreadsheet or other calculator greatly simplifies things. Homebrewers shouldn’t be intimidated by the process.

If you are unhappy with your current brewing liquor, water treatment can be a pretty easy way to improve your beer’s character.



Scott Schwartz is the Head Brewer at Nimbus Brew-ing Company in Tucson, Arizona. He monitors all aspects of the brewing process, and has garnered multiple awards for Nimbus Brewing Company, including Best Local Brew and Best Beer on Tap in the Best of Tucson competition for five consecutive years. He has a bit of a “hands-off” approach when it comes to the water supply in Tucson.

Nimbus Brewing is somewhat fortunate in relation to the local water supply. The water supply in the area of Nimbus contains the following values: sodium

31 mg/L, pH 7.7, hardness 109 mg/L, mineral content 236 mg/L and chlorine 0.73 mg/L. Currently all of our water is charcoal filtered. The water used for mashing is boiled the day before and allowed to sit overnight to assist in driving off any extra chlorine character. This also aids in the removal of bicarbonate ions by precipitation. Additionally, food grade phosphoric acid is used in lower pH to 5.2–5.4.

Nimbus doesn’t really focus on ions. Whereas calcium, sodium, chloride and sulfate add to a proper mash and finished product, as luck would have it we are fortunate to have a more than suitable profile for ales. The mineral ion content in Tucson is similar to Burton-On-Trent. All of the Nimbus ales benefit from the hard water supply, especially our pale ale and our oatmeal stout. We currently do not brew lagers so we do not have the need for soft water.

Most major cities will provide a brewer with a general water profile. If a brewer is focusing on any specific style, I would suggest buying water from a water supply store that can offer a detailed profile. You can certainly blend municipal water with softer purchased water for achieving a profile more suited to lagers.

I would also highly recommend reading “Designing Great Beers” by Ray Daniels and “The Brewers Companion” By Randy Mosher. Both books offer vast insights to both water chemistry and excellent style backgrounds. Brewers should research a style before brewing and sampling styles of the beer you want to brew is part of the joy of brewing!



Garrett Heaney is the Associate Editor of Brew Your Own and writes “Beginner’s Block” and “Tips from the Pros” in each issue.