Although most brewers spend plenty of time agonizing over their choices in malts, hops, and yeasts, they sometimes forget to pay attention to the other crucial ingredient in beer: water. Even minor variations in the chemical content or pH level of your water supply can drastically alter the flavor and smoothness of your brew, which is why you should always have your water tested if you are brewing using tap water. Testing the carbonate hardness and alkalinity of your water is particularly important to prevent bitterness and astringency, and it may impact the types of beer you can successfully produce without water treatment.
Understanding Tannins and pH Levels
Tannins are a form of polyphenolic molecules derived from plants. They are responsible for the distinctive, bitter taste in beers and wines, and they can be extracted from both hops and malts. High concentrations of tannins, however, can make your beer too astringent, ruining the flavor. The tannins found in hops and malts are released most efficiently at a pH of 5.8 or higher. Because of this, alkaline water can drag the pH of your mash too high and result in a more bitter beer.
Testing Your Water Hardness
If you suspect that you live in an area with hard water, you should have it tested (by professionals such as those from Funks Drilling Inc) before attempting to brew with it. High carbonate hardness levels point to high alkalinity, which you will need to adjust for in your mash. This water testing will also show you the mineral content of the water, which should be accounted for in your recipe as well to avoid any unwanted chemical reactions and strange flavors.
Brewing Beer to Match Your Water's Alkalinity
If your water is alkaline, you may still be able to brew an excellent batch of beer with it. Darker beers are more acidic than lighter brews, meaning they can counteract alkaline water to still produce a smooth and delicious beer. If you do want to create lighter beers, however, you will need to find a way to lower the overall pH of your water or mash.
Treating Your Water for Better Homebrewing
Treating your water directly may be the most effective way to improve your homebrewing since it will remove other impurities and can also extend the lifespan of your plumbing and appliances. A reverse osmosis filter is one of the most efficient means to purify water, using a fine membrane to filter out dissolved particles in water. This filter can catch the carbonate molecules responsible for alkaline water, leaving you with more pH-neutral water to work with. If you are serious about producing high-quality beer at home, installing a water treatment system for your house may be the wisest investment you can make.