Wipe out your water worries

Of the four ingredients of beer, water makes up the greatest portion of the physical product. By weight and by volume, plain old H2O constitutes more than 90 percent of the average beer.

Thanks to advertising for the mass market beer brands, most Americans believe that water is a critically important ingredient in beer flavor. Furthermore, most people think that only "pure" water makes good beer. Let's look at the subject of water for a minute in order to better understand its importance in beer. From this, we can see how to treat water for the average homebrew.

First of all, the term "pure water" can have a couple of meanings. On one level, people connect purity with safety and potability. They expect that "pure" water will be free of dirt, bacteria and dangerous chemicals. In the U.S., all drinking water generally achieves this standard.

On a higher level, "pure water" can mean "nothing but water." This is tricky since every natural water source -- and virtually all the water we drink -- contains small quantities of dissolved minerals. This includes things like calcium, magnesium, sulfur and chloride. These elements give water its hardness and even very soft water will have some mineral content. To get water that has no mineral content requires some form of serious treatment such as distillation or reverse osmosis.

It turns out that using "nothing but water" (e.g. distilled water) for making beer doesn't work very well. During both mashing and fermentation, beer requires the natural minerals found in water. Without these minerals, the enzymes that drive the chemical reactions of brewing won't function properly.

We can learn a lot about brewing water by looking at the great brewing centers of the world. Munich is famous for dark lagers; Pilsen for light lagers. On the ale side, the cities of London, Burton-on-Trent and Dublin are best known. Of these five, four have water with moderate to extreme hardness. Only Pilsen (in the Czech Republic) has very soft water.

So what does this tell us? First, that great beer can be made with virtually any type of potable water, from very soft to very hard. Second, it tells us that very soft water is not ideal for making most of the world's great beer styles.

Finally, we see that different types of water are used in making different types of beer. This indicates that water minerals have an impact beyond mere chemistry -- that they also affect flavor. The second article in this water chemistry series (planned for June 1997) will talk about the individual minerals and their flavor impact. But before we worry about these details, we need to cover some more basic issues.

In addition to the minerals that we have discussed, most drinking water has been treated with chlorine. This is done with either gas or with a hypochlorite solution similar to laundry bleach. In either case, the purpose is to prevent the growth of bacteria in the public water system.

Unfortunately, chlorine can produce some undesirable effects in beer. For one, it can have an inhibitory effect on the growth of yeast. Second, it has been implicated in the formation of unpleasant flavor compounds known as chloro-phenolics. These compounds taste like plastic resin or burning electrical wire. Not a good thing to include in your beer.

To avoid these effects, most brewers remove chlorine from their water before brewing. There are several ways to do this. The low-tech way is to simply boil the water for 30 minutes or so prior to adding any malt or hops. This volatilizes the chlorine to separate it from the water, but requires a bit of time prior to brewing. This approach can be awkward when you need 6 gallons of water but can only boil 4 gallons at a time. Also, if you need cold water to fill your fermenter, you'll have to boil and then chill the water, wasting both time and energy.

The best alternative to boiling is the carbon filter. This method is routinely used in commercial breweries and by most serious homebrewers as well. Home-sized units are found in most hardware stores and come in various sizes and capacities. For brewing, it is easiest to use a unit that attaches directly to your kitchen faucet. These usually have a by-pass valve for times when you want unfiltered water for cleaning and they provide a reasonable flow-rate, usually for less than $30.

One caveat on the use of carbon filters. You should never run hot water through the filter; use cold water only. Using hot water will encourage bacterial growth inside the filter itself. In addition, it may liberate the built-up crud on the carbon matrix, releasing it into your brewing water.

With the chlorine out of your water, you might start thinking about other aspects of water chemistry. Water chemistry isn't very complicated, but your consideration of it is entirely dependent on the character of the water you normally brew with. Before we can even begin to consider what changes you might want to make, we have to know what is in your water to begin with.

To do this, you'll need to get an analysis of your local water supply. You can usually get the local water company to mail this to you simply by phoning in a request. Since it may take a couple of weeks to get the analysis, go ahead and call in the request. When it comes -- or if you have this data already -- e-mail it to me. In the June water column, I'll be talking about water treatment for various types of water and different styles of beer. If you send me your profile, I'll try to include it in the examples.

Here's what to ask the water company for.