BYOB by | Feb 2010 | Issue #37

Illustration by Scott Murry

Water, if the experts are to be believed, will be one of the chief resource battles in the coming years. Already we’ve covered “green” water efforts that we can employ to lower our ecological and wallet-ological impact, but we’ve never talked about what water means to beer. Given that it’s one of the four “legal” beer ingredients and that it comprises 95 percent of our brew (or 90 to 85 percent, for some of us), ignoring water’s impact can relegate your brew to the drain.

Water chemistry may be the stuff of doctoral dissertations, but there are a few simple bits you can utilize to improve your beer without going full geek. So sit back and prepare for two months of agua for dummies (aka me!).

Your tap water, reviled by gym rats, yoga fanatics and bottled-water magnets, remains a glorious example of modern sanitation. Before the rise of the municipal water services, water could kill you dead—that’s why folks drank beer. But that life-saving sanitation serves as an impediment to zymological practitioners.

Chlorine (or its more stable cousin, chloramine) must be removed to prevent the formation of chlorophenols (aka Band-Aid smells). To do this, slowly carbon filter your water (< 1 gallon per minute). Reverse osmosis or distilled water works well as a foundation for water you modify. As an alternative to filtering, add a crushed campden tablet to your water and let sit for a few minutes. This is highly effective at removing chloramine and is all I do to my water. Outdoor brewers should invest in a “white” potable water hose to avoid another phenol source.

What is “water hardness”? Years of soap commercials have pounded this notion of “hard” water. Thanks to its soap- (and pipe-) destroying properties, generations of American families dutifully installed water softeners to the house and then trucked in bags of salt yearly. First, excess salt is terrible for beer, so don’t use “ion exchanged” softened water. Secondly, if you listen to the guys out there who really know their water chemistry, they’ll tell you that water hardness is meaningless for beer. What matters is the overall mineral content of your brewing liquor.

The best way to determine your water profile is to call up the folks at Ward Labs and order a W-6 test. For $17, you’ll get the exact makeup of the water at your faucet. Too rich for your blood? Thanks to the federal government, you can get a general profile via your water district’s EPA-mandated annual water report. Large districts put their reports online. Smaller districts may require a call to receive a mailed copy. You’ll find the important numbers in the “Secondary Standards” segment of the water report. Highlight and record the values for alkalinity (or bicarbonate), calcium, chloride, hardness (as CaCO3), magnesium, sodium and sulfate.

Alkalinity measures the carbonate level of your water. Carbonates buffer the acids found in roasted malt. Darker beers work better in alkaline water (think Dublin and Munich). Calcium lowers the mash pH naturally, and promotes conversion and fermentation. You need at least 50ppm. Chloride has no chemical impact, but promotes a full malt flavor. Magnesium, like calcium, reduces mash pH, but it’s less effective. While the yeast needs a small portion (20ppm), too much adds a sourness. High potassium levels (atypical in the US) will hamper mash enzymes. Sodium serves as a flavor booster when used sparingly. Sulfate accentuates hop bitterness, hence the bright hoppy Pales and IPAs of Burton upon Trent.

Next month, we’ll get into how you manipulate your water. We’ll talk about the magic salts that can tame the bite of a Stout and shift the balance between hoppiness and maltiness. In the meantime, enjoy this Pilsner recipe. Use the least-mineral-laden water you can for a clean hoppiness; add a little gypsum to give it a bite.

For 5.5 gallons at 1.056, 3 SRM, 42.5 IBU – 60-minute boil

Malt / Grain / Sugar
12.00 lb. Pilsner malt (German or Moravian)

3.5 oz. Czech Saaz | 3% AA | Whole for 60 minutes
0.5 oz. Czech Saaz | 3% AA | Whole for 5 minutes

Wyeast 2278 Czech Pils

Protein rest – 125˚F for 20 minutes – strike with 3.75 gallons of low mineral water
Intermediate rest – 148˚F for 20 minutes
Saccharification rest – 153˚F for 60 minutes

Ferment for four weeks at 50˚F, ramp down to 32˚F and hold for four weeks before packaging.

*Boho the Hobo Pils originally appeared in Chapter 5 of The Everything Homebrewing Book.