Understanding Water Reports
We return to water this issue because as it turns out, the composition of your water, being more than 90 percent of your beer, is incredibly impactful on the final nature of your beer. Most brewers will forgo messing with their water early in the hobby — first out of not knowing that it’s important and then believing the topic is too complicated for the impact it has — before finally trying to crack the H2O molecule. We firmly believe that adjusting water to fit a certain profile to complement the beer style being brewed is worth the time it takes to understand this subject.
Manipulating your water profile is often the last piece that pushes someone’s beer from “pretty good” to “hot damn.” But we understand why people don’t tackle it. Water chemistry is intense stuff. Unlike many other parts of brewing, the science is much harder to wave away behind a magical calculator because there are interactions upon interactions, upon interactions. And it all starts with reading a water report.
Fun fact: In the U.S., your water district is required to test and report on the quality of the water they feed into your local system. No matter how big or small, they are also required to make that reporting available to the public (though, as we’ll discuss later, these reports aren’t always as helpful as you’d assume as water sources may change throughout the year). Turns out that knowing what’s in your water is important to more than just brewing. As brewers starting with the water available in your household, these water reports should be used to make decisions in how you treat your brewing water.
Water Reminders
Before we dig into the nature of water reports and how to use them to tell you something useful, here are some fundamental water rules that the two of us follow:
Your brewing water should taste clean with no off-flavors, sulfur, metals, etc.
If you do nothing else to your water, remove any chlorine or chloramine from it. (Unless you’re on a well, odds are good your water has one of those compounds. Either slow carbon filter (under 1 gallon/4 L per minute) or a pinch of metabisulfite powder will do the trick.
When choosing a water profile, we skip “city profiles” and prefer to go on profiles based on beer color (pale, amber, brown, black) and malt balance (dry, balanced, full). See Table 1 on the facing page for good starting points for different types of beers.
Don’t obsess over trying to dial in numbers to match a target water profile. No matter what your favorite water calculator tells you, your additions do not need to be that precise and perfect.
Use your salts for flavor (and basic chemistry). 50 ppm of calcium and under 50 ppm of sodium are generally safe rules of thumbs. Don’t try and dial in your pH with calcium additions!
Don’t go overboard with your salt additions. Keep additions simple and your numbers in reasonable ranges — you’ll mostly just need small touches of gypsum and calcium chloride.
Use lactic or phosphoric acid to adjust your mash pH.
On to the Water Report
As we said earlier, your water provider is required to publish reports on water quality and these days they’re invariably online. Search for your water provider and “annual water reports.” Odds are pretty good you’ll get a clear result.
Example: Drew Googling “Pasadena DWP water report” returns: https://pwp.cityofpasadena.net/waterqualityreports/ where the Department of Water and Power has reports available going back to 2001.
Caveat: Be aware that these water reports are essentially averages of what’s happening in your water area and not a guarantee that the water pouring out of your taps has the exact same profile. In fact, in a number of places, the water profiles will change over the year as water sources are added, removed, and blended. (The water profile in Los Angeles dances between soft Sierra snow melt and mineral-laden Colorado River water, amongst other sources.) In fact, some areas may have different water sources from one day to another, in which case relying entirely on a water report may be far off from your actual water at any given time. If you want something more precise, read on, but in most cases your water report averages will provide you a general starting ground.
Pull up your water report. Find the longest version they offer. Everything we care about as brewers is generally buried in tables called names like “Secondary Standards” and “Other Parameters.” These are characters that aren’t health and safety motivated (like lead, uranium, etc.), but instead taste, flavor, and odor motivated.
For most brewing applications, what we are trying to find is water pH, alkalinity, calcium, magnesium, sodium, chloride, sulfate, and perhaps total hardness and bicarbonate (these last two can be back calculated from other values). Total hardness is generally a measure of calcium and magnesium.
By the by, don’t get fooled into thinking “hard water is bad for brewing.” There are plenty of ways and styles to brew with hard water. What we mostly will care about is getting our mash pH into the right range and adjusting those salts to impact our flavors.
In those tables, many of the needed numbers are directly expressed in parts per million (ppm) or mg/L. Plug those straight into your favorite water calculator of choice. (We use Bru’n Water, plus the calculators in Brewfather and Grainfather — the later two are fairly straightforward but Bru’n Water is the most accurate and flexible once you’re configured. Go listen to Episode 45 of the Brew Files if you want
to hear a guided tour of setting it up, available at www.experimentalbrew.com/2018/09/19/brew-files-episode-45-water-water-everywhere.
It is critical you pay attention to the listed units on both your water report and your calculator. The numbers aren’t always plug and play. In particular, pay attention to the units around total hardness, bicarbonate, and alkalinity as they get expressed in different ways by different reports. For instance, both hardness and alkalinity get reported as “mg/L (or ppm) as calcium carbonate CaCO3,” but not always. Sometimes sulfate gets reported as SO4-S instead of just SO4. Why this matters is Brewfather wants SO4-S, where Bru’n Water wants SO4.
The maddening part about water reports is they don’t always have things listed as you need, but modern calculators can generally help you out. Alkalinity is one that used to be difficult to find, but in a recent survey appears to be more common now. With most of the facts in hand, your water calculator can help you reverse engineer and double check your values. The software should report a value of how closely the cations (calcium, magnesium, sodium, etc.) and anions (bicarbonate, carbonate, chloride, sulfate, etc.) balance chemically and warn you if you’re too far afield.
Additionally, don’t hesitate to reach out to your water company and ask them “can you give me a hand?” You may be surprised at how much information a polite request will garner you. Stuff that’s not listed in the water report may actually be tracked.
But what if you’re on a well, like Denny? At that point, you’re going to need to generate your water profile. There are brewing oriented test kits like LaMotte’s BrewLab or Sensafe’s eXact iDip. You can feel like a kid with a chemistry set all over again! Or if you want something more precise (and this goes for those with water district reports as well), order a W-501 Brewers’ Test from Ward Labs (www.wardlab.com/). It costs about the same as a batch of beer, but it tells you precisely what’s coming out of your taps at the time.
One nice bit of handiness about that Ward report is that it’s become such an industry standard that most water calculators directly tell you how to input the water report. If you’re truly serious about adjusting your water, a lab report is well worth the investment. The precision in these reports is superior to the average rates reported by municipalities. See Table 2 above with some real numbers and see how far off some can be.
If you use reverse osmosis (RO) or distilled water, your water profile, assuming that the filtration systems are properly maintained and functional, is effectively zeros across the board. (You’ll definitely want to confirm this with a total dissolved solids tester.) And if you’re using “spring water” or “drinking water,” check out the source company — they too might have a water report you can use as well.
If you really want to dig in deeper on water, but not as deep as Water by John Palmer and Colin Kaminski, we’d recommend reading the basic tutorials at brunwater.com and Kai Troester’s water tutorial at braukaiser.com
