Learning Lab: Water Treatment for All

Decent beer is definitely good but learning about water chemistry can give you additional control over what you brew and take your beer from good to great.

Jester Goldman Jul 27, 2019 - 10 min read

Learning Lab: Water  Treatment  for All Primary Image

Are you ignoring the biggest component of beer? If so, you’re not alone. Most homebrewers have been at it for quite a while before they bother to think about their water. As long as it’s clean and tastes okay, water is easy to take it for granted.

Water doesn’t really show up on brewers’ radar until they start making all-grain batches. Even then, some people reduce water treatment to a poorly understood habit of tossing in some gypsum or maybe some Burton salts (brewing salts). It’s time to give water some serious thought.

Water Primer

The main reason brewers pick up anything about water treatment is to control mash pH, but their focus is tightly constrained to that goal. There’s a pH sweet spot, between 5.2 and 5.6, where the enzymes work most efficiently. Your grain bill has a significant impact on where your mash will end up, with darker grains pulling the pH down, but the initial water pH and alkalinity define the foundation you have to work with.

In fact, that’s why different regions’ water profiles historically influenced what styles worked out the best. (That leads some homebrewers to reproduce a particular water profile for a given style of beer.) Areas with higher alkalinity were usually more successful with darker beers, independent of any water modification that a brewer might have made.


The alkalinity is caused by dissolved carbonate or bicarbonate ions, which act to buffer acid’s ability to pull the pH lower. Gypsum drops the pH a little, so a default addition can end up working fine, but that’s assuming that your water is not too alkaline and that there isn’t too much dark grain in the grist. If you’re lucky, that habitual bit of gypsum can pull the pH into the right zone without overdoing it.

To eliminate guesswork and hit-or-miss solutions, the starting point is a water report from your utility company, or you can have your water tested. Once you have a good assessment of your water, there are plenty of online resources for learning more about mash chemistry, including some useful calculators to help you bring it in line.

Getting your mash pH in the zone is a bare minimum. Interestingly, though, even if you ignore mash pH, water chemistry can still have a big impact on how your beer tastes. In this Learning Lab, we’ll look at a select set of ions and the effects they have. Although we use malt extract in the experiment, this is relevant for all brewers, extract and all-grain alike.

Key Ions

The ions in brewing water are the positive (cation) and negative (anion) components of the minerals dissolved in the water. The two most important aions to cover are sulfate (SO4-2) and chloride (Cl-1). Sulfate brings out hops bitterness, while chloride tends to emphasize malt and sweetness. That contrast drives some general style-specific recommendations about the ratio between the two. Hoppier styles such as a West Coast IPA work best with a sulfate-chloride ratio of about 4:1 (four times as much sulfate as chloride), while maltier styles would flip it over to something like 1:2. The ratio is pretty useful, but there are practical limits: If the actual levels get too high, your beer will pick up harsh, minerally off-flavors or worse. But how much is too much? A good rule of thumb is to keep sulfates lower than 400 ppm and chloride lower than 200 ppm.


A key cation in brewing is calcium (Ca+2). Aside from its role in acidifying a mash, calcium helps yeast settle out, contributing to clarity and flavor stability. Put this together with planning your sulfate-chloride ratio, and your easiest water treatments are gypsum (calcium sulfate) and calcium chloride.

There are other interesting ions, such as sodium (Na+1), magnesium (Mg+2), and carbonate (CO3-2), but they play a lesser role. Smaller amounts of sodium can sharpen a beer’s flavor profile, but it’s not all that common unless you’re making a gose. Of course, if the carbonate is too high, any beer will come across as dull and lifeless.

The Experiment

Our experiment is based on a simple, fairly balanced amber ale. Between the caramel malt and the hopping rate, this recipe should provide a decent canvas for evaluating the effect of our water treatment.

Given that everyone’s water is different, we’ll set a standard blank slate by using reverse-osmosis (RO) water or distilled water as our base. The malt extract will contribute some minerals, based in part on what the manufacturer used in their mash, but the dilution will allow our water treatment to stand out.


Volume (after boil): 1 gallon (3.8 liters)
OG: 1.056
FG: 1.014
IBUs: ~38

Mash: 1.25 lb (567 g) light dry malt extract (DME); 5 oz (142 g) 80L crushed crystal malt
Hops: 0.125 oz (3.5 g) Amarillo hops [8.6% AA] at 60 minutes (bittering); 0.125 oz (3.5 g) East Kent Golding hops [5% AA] at 30 minutes (flavor); 0.125 oz (3.5 g) East Kent Golding hops at 5 minutes (aroma)
Yeast: ½ package SafAle US-05

Water Treatments
The experiment will contrast four different water treatments:
- Untreated distilled water
- Sulfate-heavy: 1 g gypsum dissolved before steeping the crystal malt
- Chloride-heavy: 1 g calcium chloride dissolved before steeping the crystal malt
- Balanced: 1 g gypsum and 1.2 g calcium chloride dissolved before steeping the crystal malt

Directions for Each Batch
Fill your pot with 1 gallon (3.8 liters) of treated water plus the makeup for evaporation loss. Put the crushed crystal malt into a small nylon grain bag. Turn the heat to medium and allow the crushed grain to steep, stirring occasionally. After about 20 minutes or if the temperature hits 165°F (74°C), pull the grain bag out of the water to avoid extracting tannins from the grain.


Remove the brew pot from the heat and add the DME. Stir it well to dissolve, then place the pot back onto the burner and bring to a boil. Boil for 60 minutes, following the hops schedule above.

Chill the wort to pitching temperature (use a cold-water bath or immersion chiller). Transfer to a gallon jug and the pitch yeast.

After primary fermentation has finished, bottle with about 0.8 oz (23 g) total dissolved priming sugar. Allow 2 weeks for carbonation.

Repeat the above process for each of the water treatments.



Pour a sample of each beer and take in all of the details of appearance, aroma, flavor, and mouthfeel. See how the actual beers compare with your expectations. The untreated beer provides a baseline for hops and malt balance. Contrast that with the balanced-treatment beer. Did the added calcium affect the clarity? How do the aroma and flavor differ between the two batches? You’d expect that the balanced-treatment beer to have a bit more mouthfeel and slightly more assertive bitterness.

Now contrast those two with the sulfate-heavy and chloride-heavy beers. Are they skewed toward hops or malt the way you’d predict? Dig a little deeper into the nuances of each. Does the sulfate beer have a drier, crisper finish? How does the aftertaste linger?

Next Steps

This experiment demonstrates the impact of water chemistry on your beer, but it’s necessarily a simplistic step. If you want to get more serious, you’ll need to get your water analysis as mentioned above. The best of the brewing-water calculators online will let you plug in your numbers and choose a target water profile, for example Munich Dark Lager. Then the tool can help you work out which salts to add to bring the water in line with the target. Note that those target profiles often include choices that let you play with the sulfate-chloride balance rather than just reproducing a historical profile.

If you’re an all-grain brewer and you haven’t paid much attention to water treatment, this is particularly worthwhile. It’s unlikely that you already have the perfect water, so a closer look may improve your mash efficiency and the quality of your beer. Aside from playing with different target-water profiles, you could also apply what you’ve learned to make minor adjustments to recipes you’ve already worked out. For example, a touch more sulfate may kick your IPA to the next level or give your German Pils a crisper finish.