Unlock the Secret of Water
Historically, great beer has always been the product of the happy circumstance of the location and the times.
Beer is an agricultural product, so traditionally it varies from growing area to growing area. Because of local political influence on trade and taxation, each city adopted different methods of production and sale of beer. And certainly different methods of malting, kilning, and every step of the manufacture of beer gained uniqueness from the era’s common practices. But perhaps the greatest influence on the styles of beer that have become world classics is water.
Though individuality is still the hallmark of great beers worldwide, modern times have afforded a certain measure of freedom and consistency to beer production methods. If you live in Ohio and wish to brew Belgian-style beer, you can readily purchase Belgian malts. If you wish to employ a German mash schedule or Czech hops, the information, technology, and products are only as far as your local homebrew shop. But neither you nor any brewer on any scale can practically import water from Munich to brew a true German lager. Water defines the character of any great brewing region, including the region around your home.
What Makes Water Unique?
Chemically, water in its most basic form is H20: two atoms of hydrogen per one of oxygen. But for all practical purposes your water is H20 with lots of dissolved minerals, organic material, and gasses from everything it has come in contact with on its way to your tap.
For brewing purposes ion concentration is of the greatest concern. Ions are electrically charged particles. Positively charged ions (cations) and negatively charged ions (anions) combine to form compounds. Mineral salts, such as gypsum or ordinary table salt, are examples of these compounds.
When the salts are dissolved in water they ionize, or dissociate, back into their original ions. The ions that most affect the brewing process are calcium carbonate and bicarbonate, magnesium, sodium, sulfate, and chloride.
Most homebrewers in this country rely on their own municipal water supply for beer making. Most municipal water supplies in the US are derived from deep wells, reservoirs, or rivers. The water is filtered and treated (usually with chlorine or a chlorine compound) to inhibit microbial contamination. In many locations the water is pH adjusted for corrosion control.
Your tap water should be (and probably is) clean and clear, have no strong aromas or unpleasant tastes, and be generally satisfactory for drinking. The standard rule is: If your water is potable to you, then you can brew with it. You may, however, detect some aromas and flavors in your water that send you to the store in search of the bottled stuff for everyday drinking. In any case, it’s time to take a closer look at what’s in your water and how it can work for your beer.
Analyzing Your Water
There are a lot of basics that you should know about your water supply. Where does it come from? How is it treated? Does the source water or composition vary at different times during the year, and for what reasons? In some areas rainfall may affect the amount of dissolved minerals in the water. Where rivers are the source for a local water supply, the composition may vary greatly depending on the height of the river stage. How is the water treated? And last and perhaps most important, what are the dissolved minerals?
The easiest way to find out all of this information is simply to put in a call to your local water department. Departments usually publish an annual report detailing all aspects of the water supply. In some cases they include this report with the regular bill. Don’t worry about asking all kinds of questions over the phone. Simply call and ask for a copy of the water quality or water analysis report, and you should find that it contains all of the information you need.
The municipal water quality report for the city of San Francisco, for example, is a two-page report that consists of charts listing all mandatory health-related standards for clarity, microbiology, organic and inorganic chemicals, and radionuclides.
The report clearly states and defines the unit of measurement, maximum allowable contaminant level, and the range and averages for each item in treated San Francisco water. Most of these chemicals are not detected and are of minor concern to brewers.
A second page lists aesthetic standards and additional constituents such as alkalinity, hardness, pH, chlorine, and levels of key ions such as calcium, magnesium, and sodium. In addition there is a narrative describing the origin of the water and treatment practices.
It is interesting, for instance, to know that the water originates from high Sierra snowmelt in 459 square miles of protected Yosemite National Park watershed land. It is more useful, however, to know that 15 percent of the supply is derived from local reservoirs. From that fact we can assume a range of fluctuation in the content of the water supply throughout the year. Fortunately, that range is fairly small, and averages are given that can be used for brewing calculations.
The high Sierra water, stored in Hetch Hetchy reservoir, is pH adjusted with lime for corrosion control, then chlorinated to kill bacteria that may be potentially harmful.
This is important information for the brewer, and a glance at the charts provides a valuable picture of the water supply as a whole. Calcium and total alkalinity and hardness (both expressed as CaC03, calcium carbonate) are all low, but the pH is
relatively high.
The report states that “the water is pH adjusted with lime for corrosion control.” Lime reacts with calcium and bicarbonate to form calcium carbonate, which is insoluble and precipitates as a white, chalky residue. Because the water needs to travel 150 miles through tunnels and pipelines, this addition of lime to decalcify the water reduces chalk buildup in the supply lines, and it reduces buildup and corrosion of pipes in the home.
The water that comes out of a San Francisco tap, therefore, is very low in mineral content (soft), which makes it easily adaptable to all great beer styles, and even though it has a high pH, it is low in total alkalinity, which is good for the mash. Because liquid chlorine bleach is used to kill bacteria in the water, boiling, filtering, or “out gassing” the brewing water will rid it of any chlorine. By having a simple, working understanding of what and why the brewing water is what it is, you can begin to understand exactly what it is best suited to brewing.
If you use water from a well, you will need to get it tested if you want to have control over styles. You may want to do a little geological research about your area as well to get a complete picture of the origins of and changes to your water that may be occurring.
Classic Beer Styles
“Hard” and “soft” are the two terms that have the greatest significance in describing the character of famous brewing waters. “Hard” water is measured primarily by the amount of calcium and magnesium it contains. Because these ions inhibit the sudsing ability of soap, water containing high levels of them is “hard” to lather. “Soft” water is water with the absence of significant amounts of these ions.
Calcium is the most important ion that affects hardness. Calcium lowers the mash pH, aids enzyme activity, helps protein coagulation and sparge runoff, aids clarity, and accentuates hop bitterness.
The carbonate and bicarbonate ions pull the mash pH up and neutralize calcium by forming a chalky precipitate when boiled (or mixed with lime). Therefore, the ratio of calcium to carbonate is a more accurate determining factor in measuring hardness.
Burton-On-Trent, home of Bass Ale, is one of the best examples of water hardness as an influence on the development of a famous style. The generally accepted optimum range for calcium in the mash is between 50 and 150 parts per million (ppm). Burton’ s water contains a whopping 270 ppm of calcium and 60 ppm magnesium. At this level, calcium can be detrimental to the mash. But because Burton’s water also has a high level of carbonates (200 ppm), the negative effects are balanced out and the resulting water provides the background for the dry, hoppy, minerally flavor for which Burton’s beers are known.
At the other end of the hardness spectrum is the classic water of Pilsen (Plzen) in the Czech Republic, where Pilsner Urquell is made. Pilsen’s water is extremely soft, containing only 7 ppm calcium, 2 ppm magnesium, and 14 ppm carbonates. The softness of the water allows a greater intensity of malt flavor to come through while still maintaining a rich, smooth, and round palate.
By comparison Dortmund, which also produces pale lagers in the style of Pilsner Urquell, has very hard water, and the palate of its beers is accordingly minerally, lending the beer a bit more crispness.
Making the Most of the Water You’ve Got
Now that you know what’s in your water and how it will affect the flavor and styles of beer that you make, here are a few simple principles to help you make the most of your water.
Getting rid of chlorine. Chlorine that passes from your water into your beer may lead to medicinal aromas that you don’t want. Chlorine levels in your water supply can vary greatly, so your best bet is to smell your water. If there is a noticeable chlorine odor, you might want to think about getting rid of the chlorine. If the water is chlorinated, you can drive off the chlorine simply by boiling your brewing water. You may also “out gas” the water by letting it sit
uncovered for 24 hours. Your simplest option is to buy a small carbon filter and run all your brewing water through it. Carbon filtration will also work if your water department uses something other than, or in addition to, chlorine, such as chloramines.
Adjusting hardness. Boiling water that contains calcium and carbonate will precipitate a residue, thus lowering the total hardness of the water. But be aware of your original calcium levels. You don’t want to remove all of the calcium, as it is vital to a healthy mash. You can add calcium back, if necessary, in the form of gypsum (calcium sulfate) or calcium chloride.
If your water is very soft and you add calcium, you will raise hardness. Remember that gypsum, for example, is a salt (the calcium and sulfate ions combined) and it will also add sulfate to your water. So if there is already a high level of sulfate (more than 100 ppm), you may want to add calcium chloride (CaCl2) instead, to avoid harsh flavors that may be associated with high levels of sulfate.
Using bottled water. Just like tap water, bottled water needs to be tested for chemicals and ion concentrations. Your bottled water supplier should be able to provide you with the information.
Brewing water and extract. Extracts are worts that have already been made for you. When the grains were mashed, the water was adjusted to optimum levels for the style of extract being made. You may wish to drive off chlorine from your brewing water, but you probably don’t need to adjust the ion content of your water if you are using extracts.
Other Components
In addition to chlorine and the few ions previously mentioned, there are several other components of your water that may affect flavor.
Generally, there are trace amounts of all kinds of nasty chemicals in our water supply, but they are negligible and won’t have an effect on your beer. Certain inorganic chemicals such as nitrate and nitrite can affect your beer, but these shouldn’t be a problem unless you are using suspect well water. If you see levels above 5 ppm, you should find an alternate water source.
Some chemicals such as copper, lead, and iron are totally undesirable in your brewing water and should be present in amounts of less than 1 ppm. Don’t worry about copper and lead pipes in the brewery; the metals will not dissolve into water from pipes. You probably don’t have lead utensils lying around the house but if you do, don’t use them in your mash or beer. Lead will dissolve in acid solutions.
Most municipal water supplies are fluoridated. The levels found in your water will not affect brewing.
Other Ions
A few common and important ions are sodium, chloride, and sulfate. Common table salt is sodium chloride (NaCl), which can be added to water to accentuate sweetness and smoothness. Avoid iodized table salt because iodine is toxic to yeast. You probably don’t want to add sodium chloride and
gypsum together, because adding gypsum (CaS04) is also adding sulfate. Sodium and sulfate together may make the beer unnecessarily harsh tasting. Consult your water analysis charts for levels, but the more sulfate in your water, the less sodium you want to introduce and vice versa.
Classic Brewing Water
Burton and Pilsen are just two of the classic defining waters that have led to some of the world’s great styles. You know the beer, you know the water, now put the tastes together in your mind.
London. London’s water varies from district to district, but an exemplary London water supply is low in calcium (52 ppm) and high in carbonates (156 ppm). Though the high alkalinity of this water would make brewing pale ales difficult (the pH of the mash would be too high), it is perfectly suited to brewing porters because dark roasted malts are naturally acidic and will overcome the buffering power of highly carbonate waters, lowering the mash pH into the correct range. High levels of sodium (100 ppm) may accentuate the chocolatey sweetness of the porters that made London famous. Example: Young’s London Porter.
Dublin. The name Dublin is synonymous with one beer — Guinness. Guinness’ unique production process makes the world’s greatest dry stout, but what about the water? Though the water is reasonably high in calcium (118 ppm), it is also very high in carbonates (319 ppm). Therefore, again, it is well suited to the use of lots of highly acidic dark roasted malts.
Munich. Unlike the water of Dortmund to the north, Munich has a very carbonate water supply (75 ppm calcium, 150 ppm carbonates). Its lagers, therefore, tend to have a distinctively sweet, malty profile to balance the carbonate water, and they are generally fuller bodied and slightly darker than other pale lagers. Munich also perfected other lager styles employing slightly darker malts such as Märzen and dunkles. Examples: Spaten Pils, Paulaner Dunkel, Ayinger Fest-Märzen.
Vienna. Vienna’s water is hard (200 ppm calcium, 120 ppm carbonates), and its beers will taste minerally. Its water also has a fairly high sulfate concentration (125 ppm), which contributes to the characteristic dry finish and may accentuate the nuttiness of the high-kilned malt. Examples: Ottakringer 150 Jahr, Dos Equis Original Amber (from Mexico).
St. Louis. The home of the world’s largest brewer has an excellent all-around water supply for brewing except for its slightly low calcium content (25 ppm). It is generally fairly low in carbonates (50 to 120 ppm, depending on river stages) and has a good balance of the other ions relevant to brewing. Sodium (50 ppm) probably contributes a bit of sweetness and sulfate (100 ppm) for a slightly dry finish. Example: Budweiser.
