Since water makes up 85-95% of beer, one could argue that it is the most important of all your brewing ingredients. Historically, breweries have been located near readily available water sources, with some places gaining more fame than others over the course of time. Burton-on-Trent in England, Pilsen in what is now the Czech Republic, and Dublin in Ireland, only to name a few, are brewing cities famous for their water profiles and the iconic beers they produce. While it is tempting for homebrewers to imitate the water profile of a particular place when brewing a beer associated with that locality, too much tinkering with your existing water supply can lead to more harm than good. In any case, a proper analysis of your brewing water supply must precede any potential changes you make to it. Water chemistry is a delicate balance of minerals and pH level that lends your beer a particular terroir. Before you explore another city’s or region’s sense of place through its brewing water, first explore your own.

Whether you’re brewing extract-based or all-grain beers, obtain a water report from your local utility company in order to assess what you’re brewing with. I will present to you my water profile and explain each aspect in detail.

My Water Profile:

Alkalinity (measured as CaCO₃—Calcium Carbonate) = 54.06 ppm

·         Preferred brewing ranges:

o    Pale beers: 0-50 ppm

o    Amber, malty beers: 50-150 ppm

o    Dark, roasted beers: 150-250 ppm

Alkalinity is a liquid’s ability to resist a change in its pH value when acids are added. Hence, the higher the alkalinity, the higher your water supply’s pH level will be. If your water report does not list alkalinity measured as calcium carbonate, but does list a value for bicarbonate measured as HCO₃, then multiply that value by 0.82 to receive the equivalent value in CaCO₃. Your alkalinity level will have an important impact on your mash pH and subsequent extraction of sugars, proteins, and other nutrients from your grains.

Bicarbonate (measured as HCO₃) = 65.88

·         Preferred brewing ranges:

o    Pale beers: 0-50 ppm

o    Amber, malty beers: 50-150 ppm

o    Dark, roasted beers: 150-250 ppm

In addition to being a measure of alkalinity, bicarbonate also represents a measure referred to as temporary hardness. Temporary hardness can be reduced through boiling. Nonetheless, even if your water supply has high levels of bicarbonate, its removal will still likely yield high levels of permanent hardness. Water supplies high in permanent hardness lend themselves to brewing darker beers, and it is one of the reasons why Dublin is famous for its stouts.

Calcium = 50.01 ppm

·         Preferred brewing range: 50-150 ppm

Calcium is the main determinant of water hardness. Higher concentrations of this ion lower the pH value of your water supply. Its presence also aids enzymes in the mash and promotes yeast growth and flocculation. Burton’s water contains 352 ppm of calcium.

Chlorides = 180.21 ppm

·         Preferred brewing range: 0-250 ppm

Chlorides bring out flavor and a well-rounded fullness in your beers. However, extremely high levels from heavily chlorinated water will result in harsh and medicinal flavors in your beers. Boiling your water will remove some of the chlorine.

Magnesium = 17.02 ppm

·         Preferred brewing range: 10-30 ppm

Magnesium contributes to water hardness, but plays a more important role in yeast health. When present in higher than recommended concentrations, it can contribute bitterness and astringency to your beer.

Sodium = 160 ppm

·         Preferred brewing range: 0-150 ppm

Within its preferred brewing range, sodium complements malt sweetness, providing a fuller flavor profile. Above 200 ppm, saltiness will become noticeable and detract from your beer.

Sulfate = 34.04 ppm

·         Preferred brewing ranges:

o    Normally bitter beer: 50-150 ppm

o    Very bitter beers: 150-350 ppm

Sulfate contributes to permanent hardness along with calcium and magnesium. It provides dry and crisp, but pleasant bitterness in high concentrations. The water in Burton contains about 820 ppm of sulfate.

pH = 8.7

·         Preferred brewing range: 6.0—7.5

Your pH value represents the concentration of hydrogen ions in your water supply. However, the pH of your water supply is not nearly as important as the pH of your mash.

Estimated mash pH = 5.7—5.8

·         Preferred brewing range: 5.2—5.4

The pH level of your mash is crucial because it affects enzyme activity in your mash and yeast performance in your fermenter. Malted grains are naturally acidic, so when you add them to your brew water, the pH automatically drops. Alpha amylase performs best between pH values of 5.3 and 5.7, while beta amylase thrives between 5.1 and 5.3. During the boil, the pH of your wort will drop even further, likely approaching 5.0, which is optimal for your yeast to kick into vigorous fermentation. Fermentation will further lower the pH value of your brew to between 4.0 and 4.5. The acidity of beer combined with its alcohol content is extremely hostile to bacteria. You can use this formula to estimate your probable mash pH: (Alkalinity as CaCO₃ ppm/50) – [((Calcium ppm/20) / 3.5) + ((Magnesium ppm/12.1) / 7)] = Residual Alkalinity. Then use your Residual Alkalinity measure on this slide rule to find your estimated mash pH. Yet, the only way to figure out your true mash pH is to measure it using pH papers. When using pH papers be aware that they are generally designed to measure pH at room temperature, not mash temperature, so when you take a pH reading at mash temperature, add 0.3 to your measurement because pH is lower at higher temperatures.

Water chemistry is as complicated as it is important. Although my calcium and sulfate levels are a little low, while my sodium concentration is a tad high, I have not radically adjusted my brewing water other than the fact that I use a charcoal filter, which removes chlorine and other undesirable organic flavors without affecting existing mineral concentrations. If your water profile is generally within the recommended ranges and you’ve been brewing tasty beer with it, then you likely don’t need to change anything unless you want to experiment. If your brewing water supply is not reliable or off the charts in its mineral concentrations, you might consider starting from scratch with reverse osmosis or distilled water that you can adjust using various salt and mineral additions. When formulating your brewing water from scratch, carefully calculate and keep track of what and how much you’re adding. Instead of mingling with mineral concentrations, the most significant improvement you can make to your brewing water is to control your mash pH. I use 5.2 pH Stabilizer for consistent results since my untreated mash pH is rather high. The reason why Burton-on-Trent, Dublin, and Pilsen, which has most of its mineral concentrations in the single digits, became famous for their particular beers is because they were blessed with unique water supplies and they did not meddle with them. We all have unique water supplies as well, and while the line between unique and off-putting can be very thin, it is worth toeing before stepping into a totally different puddle of water.