The forgotten ingredient

Often, when someone suggests placing a pitcher of water on a dinner table, I make a stupid joke: “It’s OK, this is mostly water,” I say while pointing at my beer glass. I think it’s funny.

Of course, it’s also a simple fact. The average beer is more than 90 percent water. Yet water is probably the least recognized of beer’s four essential ingredients. Malt, yeast and especially hops get most of the attention, while water tends to run quietly under the bridge.

That’s certainly because H2O occurs so ubiquitously in our bodies, our environment and our food and drink that we think nothing of it. To do so would be, in a sense, redundant.

“Water, like air, is so essential we take it completely for granted, to the point of forgetting all about it,” explains British beer writer Pete Brown in his new book, Miracle Brew: Hops, Barley, Water, Yeast and the Nature of Beer. The book is a thoughtful, heavily researched ode to the four main components of beer, and the chapter on water is called, fittingly, “The Forgotten Ingredient.”

The fact that we have the luxury to forget all about water is, of course, a good thing. However, even clean, safe-to-drink water has the potential to be chemically off-balance to the point of harming a beer, and so water deserves some attention. Good brewing water is slightly acidic, with a blend of minerals like calcium and magnesium. On the other hand, soft water—that is, water lacking in mineral content—must be pretreated with salt and mineral tablets before brewing. Beer made with soft water can be dull or “flabby” tasting.

“But as a general rule, if you can drink the water, you can make beer with it,” says San Rafael homebrewer Damien Perry, also the president of the Marin Society of Homebrewers.

Perry says he made beer several years before ever thinking about the chemistry of his water. Today, about the only component of tap water that concerns him is chloramine, which most water suppliers add to municipal supplies to stifle bacterial growth. Especially if you’re using smoked malt in a beer recipe, chloramine can be problematic.

“Chloramine reacts with some smoked grains, so you can taste it,” Perry says. “It can give you a terrible burning-tire, burning-rubber taste.”

Homebrewers use potassium metabisulfite—readily available at homebrew stores as so-called Campden tablets—to remove chloramine. The potassium metabisulfite bonds with the unwanted molecules and evaporates out of the brew water in a few minutes.

At the other end of the brewing scale spectrum, Lagunitas Brewing Co., in Petaluma, runs its water through a giant carbon filter to strip it of chloramine. Some brewers add calcium, often in the form of gypsum, to their water, especially before making IPAs. That’s because calcium can help accentuate hop flavors.

“Calcium is often associated with a nice sting from the hops,” says Jeremy Marshall, Lagunitas’ brewmaster. “It helps with making a really crisp IPA.” Calcium also bonds with various elements and compounds, as well as yeast cells, and helps to make them precipitate from the beer and settle at the bottom. “Calcium is basically good all around,” Marshall says.

Lagunitas brews with water from the Russian River—a clean source. Well water, by comparison, can be of poor quality and unfit for making beer if unfiltered. Marshall says well water often contains higher concentrations of heavy metals.

“And although most brewers love heavy metal, it is not good for beer flavor,” he says.

Water, at its best, is odorless and flavorless. Its job in brewing is to stay quiet and basically provide a medium in which the other ingredients may interact. Marshall even believes water gets too much attention at times among brewers. When a beer is good, or bad, the water isn’t usually the cause.

“The malt, the yeast and the hops are going to have so much more material impact on the beer than water chemistry,” he says. “It’s extremely rare that an off-flavor can be traced back to the water.”