Water in Brewing
For most beer styles, water accounts for more than 90% of the brew, though its contribution is largely overshadowed by more exciting ingredients like barley, hops and yeast. Water not only impacts the flavour and aroma of a beer, it also affects the bitterness, acidity, and mouthfeel. The five primary minerals in water that will affect the flavor of your beer are calcium, magnesium, sulfates, chlorides and sodium.
Calcium promotes clarity, flavour and stability in finished beer. Its presence is essential during the mashing phase, where it facilitates the conversion of starches from the grain to fermentable sugars.
Magnesium acts as a yeast nutrient, enabling and promoting proper enzymatic activity. It can accentuate the flavour of the finished beer, but too much magnesium can leave an unwanted acidic or bitter taste.
Chlorides & Sulfates together determine the “balance” of the beer. Chlorides enhance malt-forward flavours, sweetness, and body, where sulfates contribute dryness and hop bitterness. When sulfates are proportionately higher than chlorides, the beer will be more hop-forward, and when the inverse is true, you’ll have a rounder, maltier brew.
Sodium is often used to add alkalinity to your brewing water and can also improve the flavour and mouthfeel of your finished beer. At excessive levels, it can be harsh-tasting and poisonous to yeast.
Historic Beer Styles and Water Profiles
Historically, water is the key ingredient beer connecting beer to specific regions, it is the main link between a beer with a particular place. Every region in the world has unique water characteristics, hard or soft, with a different concentration of ions.
Unlike hops and malts that could travel in ancient times, water could not be transported, making it mandatory to manage its characteristics locally. These characteristics forced the brewers to adapt recipes and tailor production processes to its local water supply. Here are a few examples:
Bad Kostritz: This German town was named for its natural salt spring, “bad” meaning bath, indicating that it was a spa town. Köstritz water is especially hard, with high levels of calcium carbonate, making it particularly suitable for brewing dark beer. Because malt becomes more acidic when roasted, hard water with a high alkalinity provides a natural balance to darker malts, lending the perfect environment for brewing schwarzbier.
Burton on Trent: Burton on Trent water has high amount of gypsum, or calcium sulfate, making it an ideal choice for brewing crisp, dry and hoppy beers. A town famous for brewing, Burton-on-Trent became known for their contribution to the development of pale ales and IPAs in the 19th century.
Pilsen: The Czech town of Pilsen (Plzeň) has extremely soft water profile due to its low mineral content, and perfect for showcasing sharp bitterness of hops, and sweet biscuit of malts. The town of Pilsen is famous for conceiving its eponymous lager, and is also considered to be the beer capital of the world.
While historical brewing relied on the intrinsic characteristics of the regional water supply to determine its most suitable brews, the introduction and advancement of industrial water treatment has opened up a world of possibilities. Now, any brewery with a water treatment system can adjust the pH and mineral content to achieve the desired flavour profile suitable for any beer style.
(Leah is a Toronto based freelance writer as well as the Beer Boss and a server at C’est What)