What's in the water?

Last month we talked about the basic composition of water. During a quick review of the waters used to make classic beer styles, we discovered that many are produced from hard water with high levels of mineral content. This month, we'll look at the major minerals found in water and the actual water profiles found in some major brewing cities. Next month, we'll look at water profiles from around the U.S. and talk about how to adjust your brewing water for specific styles.

The key constituents

Here is a listing of the key water minerals and their effect on brewing and beer. In addition to these higher-volume components, many trace elements such as zinc and copper are found in natural water sources. These trace elements often play an important role in yeast metabolism -- another good reason not to use distilled water for brewing.

H₂0: This is water, pure and unblemished. This pure form is not found in nature and not at all ideal as the key water source for brewing.

Ca: Calcium. Primary contributor to hardness of water. Also plays critical role in mashing and brewing chemistry and therefore is required for successful brewing. For flavor purposes, acceptable levels 5 to 200 ppm. The usual goal is 80 to 100 ppm for mash and sparge water.

Mg: Magnesium. The secondary mineral of hardness. Enzyme cofactor and yeast nutrient that is necessary in small amounts in all brewing water. Accentuates beer flavor at 10 to 30 ppm. Contributes astringent bitterness when present in excess. Over 125 ppm, it is a diuretic and cathartic. Keep below 50 ppm in general.

Na: Sodium. Contributes sour, salty taste that can accentuate beer flavors at reasonable levels. Poisonous to yeast and harsh tasting when in excess. Usual levels 2 to 100 ppm.

Fe: Iron. Contributes metallic, blood-like or inky flavor. Levels should be less than 0.3 ppm and most public treatment facilities achieve this goal.

CO₃: Bicarbonate or carbonate. May be expressed as "alkalinity" or "temporary hardness" in water reports. Strong alkaline buffer which raises pH. Contributes a harsh, bitter flavor in combination with hops. Also promotes the extraction of tannins from grains and hops and leads to darker colored beers.

SO₄: Sulfate. Gives a dry, fuller flavor, some sharpness. Strongly bitter above 500 ppm, but characteristic of some British ales. Compliments high hopping levels.

Cl: Chloride. Acquired from table salt (NaCl) or calcium chloride, it enhances beer flavor and palate fullness. It increases perception of sweetness or mellowness. Increases stability and improves clarity. Usual levels 1 to 100 ppm in light beers. Can go up to 350 ppm in beers greater than 1.050 in gravity.

pH: A 12 point log-scale that measures the acidity or alkalinity of a solution. 7 is neutral or balanced. Lower numbers (1-6) are acidic; higher numbers (8-12) are alkaline, or basic. Water is generally close to 7, or neutral. The most common deviation is to the alkaline side where high carbonate content can push water pH as high as 8.5.

Hard-ness: Expressed as total of ions contributing to hardness. Hardness minus alkalinity equals permanent hardness.

Chlorine: The hydrated or disolved form (HOCl) is used to help sanitize public water supplies. This stuff is bad news in beer. Can give a swimming-pool-like "chlorine" flavor or smell to finished product, can corrode stainless steel equipment, can combine with organic substances to produce plastic-like or medicinal chlorine-phenol complexes. Remove by carbon filtration or boiling as indicated in last month's article on water.

Brewing center water profiles

Most brewing centers were established long before man understood the chemistry of water. Brewers learned from experience that the same formulation might produce favorable results in one city, but not in another. Thus beer styles evolved to suit the water of the city in which they were brewed. Here are the water profiles of a several of major brewing cities. Next month, we'll talk about how to treat your brewing water to match these profiles.

Water chemistry of classic brewing cities

	Pilsen	Dortmund	Munich	Vienna	London	Burton	Dublin
Calcium	7	225	75	200	52	268	118
Magnesium	2	40	18	60	16	62	4
Sodium	2	60	7	8	99	54	12
Chloride	5	60	10	12	60	36	19
Sulfate	5	120	10	125	77	638	54
Alkalinity	14	180	152	120	156	200	319

Pilsen: Very soft water allows pale color and clean bitterness of Pilsner.

Dortmund: Very hard water, with high levels of nearly all the water minerals. Used for making the medium-bitter, pale style known as "Export" lager.

Munich: High carbonate content leads to low hopping rates and darker color as found in Dunkel and Bock.

Vienna: Low sodium and chloride levels surrounded by high overall hardness. This city is famous for the production of well-balanced amber-style lagers.

London: Carbonate plus high levels of sodium and chloride encourage balanced, smooth dark beers such as porter and mild.

Burton-on-Trent: High sulfate content contributes to sharp, clean bitterness of classic pale ale, India pale ale.

Dublin: Extremely high carbonate content requires the use of acidic dark malts to achieve a more neutral pH. Thus, Dublin stouts like Guinness, include 10 percent roast barley in their grists.

Here's what to ask the water company for.