Brewing Water: A Practical Guide for Homebrewers

I recently picked up and read a copy of  ‘Water: A Comprehensive Guide for Brewers‘ by John Palmer and Colin Kaminski, and I was blown away with the complexities and intricacies of brewing water. Palmer and Kaminski did a great job with this book, and really opened my eyes to the importance of the base ingredient in beer — water — and how crucial it is to study and comprehend its role in the brewing process.

After reading through this book, I was inspired to create a condensed guide that fellow homebrewers (you) could use to make sense of a seemingly complicated subject matter.

Now, before you proceed, I’d like to mention that the information below is a compilation of information from many different resources. These resources are listed at the bottom of this page. For more information on this subject, I’d encourage you to purchase Palmer and Kaminski’s book, and visit the links of these resources. Many thanks to the authors and providers of these sources!

This guide provides first provides some information about (1) why water treatment is important for brewing, and (2) reviews the most important components in beer that have an impact on the final product. The guide then provides a few helpful metrics, and outlines a procedure for how you can apply this information into your brewing procedure.

If you have any feedback about this guide, or found it to be helpful in improving your homebrewing procedure, I’d like to hear from you! Feel free to leave a comment at the bottom of the page, or shoot me a message. Also, feel free to subscribe to my blog if you’d like updates when I publish new guides and blog posts.


Why is water treatment important?

Brewing water plays a very important role in the flavor of your homebrewed beer. Knowing the character of your local water source, as well as how to adjust it to improve your beer is a critical skill, particularly for more advanced brewers.

Water impacts beer in three ways:

  1. Mashing and Grain UtilizationWater ions are critical in the mashing process for all grain brewers, as they impact the mash pH which determines the efficiency and flavor of the extracted wort.
  2. Bitterness and Hop PerceptionWater also affects the perceived bitterness and hop utilization of finished beer.
  3. Overall Flavor ProfileFinally, water adds flavor directly to the beer itself, as water is the largest single component in finished beer.

What components in water have the greatest impact on my beer?

The effect of brewing water on beer can be characterized by six main water ions: Carbonate, Sodium, Chloride, Sulfate, Calcium, and Magnesium.

Note: mg/L and ppm are the same measurement.

  1. Carbonate and Bicarbonate (CO3 and HCO3) – Carbonate is considered the most important ion for all grain brewing.  Often expressed as “total alkalinity” on many water reports, carbonate is the ion that determines the acidity of the mash, and is the primary determinant in the level of “temporary hardness” of the water. If carbonate levels are too low, the mash will be too acidic, especially when using darker malts (which have higher acidity).  Alternately, if carbonate is too high, mash efficiency will suffer. Bicarbonates and temporary hardness can be reduced by pre-boiling the water – the precipitate that falls out after boiling is primarily bicarbonate, or diluting the source water with distilled (DI) or reverse osmosis (RO) water.

    Recommended carbonate levels are 25-50 mg/L for pale beers and 100-300 mg/L for darker beers.
  2. Calcium (Ca) – Calcium is the primary ion determining the “permanent hardness” of the water.  Calcium plays multiple roles in the brewing process including lowering the pH during mashing, aiding in precipitation of proteins during the boil, enhancing beer stability and also acting as an important yeast nutrient.

    Calcium levels in the 100 mg/L range are highly desirable, and additives should be considered if your water profile has calcium levels below 50 mg/L.  The range 50 mg/L to 150 mg/L is preferred for brewing. Can be perceived a “minerally” at high concentrations (>200 ppm)
  3. Magnesium (Mg) – Magnesium is a critical yeast nutrient if used in small amounts.  It also behaves as calcium in contributing to water hardness, but this is a secondary role.  Magnesium can be added by the brewer in the form of Epsom salt (MgSO4) to lower the mash pH. It’s important to note, additions for yeast nutrition are not necessary, as the wort typically contains more Mg than the yeast would require.

    Magnesium levels in the 10-30 mg/L range are desirable, primarily to aid yeast. Levels above 30 mg/L will give a dry, astringent or sour bitter taste to the beer.
  4. Sulfate (SO4) – Sulfate plays a major role in bringing out hop bitterness and adds a dry, sharp, hoppy profile to well hopped beers. Sulfate is only weakly alkaline and does not contribute to the overall alkalinity of water. It’s important to note that high levels of sulfate will create an astringent profile that is not desirable.

    Normal sulfate levels are 10-50 mg/L for pilsners and light beers and 30-70 mg/L for most ales. Levels from 100-130 mg/L are used in Vienna and Dortmunder styles to enhance bitterness, and Burton on Trent pale ales use concentrations as high as 500 mg/L, though moderate amounts (200 – 400 ppm) is said to increase the “linger time” of the hop bitterness, and accentuates the hop flavor and aroma.
  5. Chloride (Cl) – Chloride, like sodium, also enhances the mouthfeel and complexity of the beer in low concentrations. It provides a rounder, fuller, sweeter quality to the malt character and the beer. Chloride is usually added by the brewer in the form of CaCl2 to add calcium and lower alkalinity.

    Chloride is said to be corrosive to brewery equipment at concentrations greater than 100 ppm, however, normal brewing concentrations are around 150 ppm. Concentrations greater than 200 ppm are not desirable for many reasons.
  6. Sodium (Na) – Sodium contributes body and mouthfeel to the beer, but if used in excess will result in salty seawater flavors. It is important to note, that high sodium water often comes from household water softeners, which is why most brewers recommend against mashing with softened water.

    Sodium levels in the 10-70 mg/L range are normal, and levels of up to 150 mg/L can enhance malty body and fullness, but levels above 200 mg/L are undesirable.

BEWARE! Chlorine and Chloramine

Chlorine and chloramines are often used in city water supplies to sanitize, and can also reach high concentrations from use of bleach as a brewing sanitizer.  Heavily chlorinated water will result in “mediciny” or chlorine-like flavors that are undesirable in finished beer, called chlorophenols.

You can reduce chlorine and chloramine concentrations by using a carbon filter (this is probably the easiest), pre-boiling the water (30 minutes for chlorine, or 2 hours for chloramine) before use, UV degradation, or treating with potassium metabisulfite.

Note: Treating with potassium metabisulfite will modify the chemistry of the water by adding sodium, potassium, chloride, sulfate, and ammonia, and will also neutralize alkalinity.

Other important metrics

    1. Mash pH – The mash pH is important metric for a brewer to understand and measure the pH of the mash, as the pH has an effect on both conversion efficiency of the grain, and flavor of the end product. An ideal mash pH is between 5.2 and 5.6. Keep in mind, however, mash pH is different than source water pH.

      Helpful hint: get a pH meter! If you’re serious about understanding how water impacts your beer, this is a must-have tool.

    2. Residual Alkalinity (RA) – Residual alkalinity is also an important metric to measure because it allows the brewer to understand how the water hardness and alkalinity interact in the mash, and will set the basis for the eventual mash pH. If the value is positive, one could assume the mash pH will be higher (more basic) than 5.8, and may require an acid addition in the mash. A simplified equation for RA, using the Kolbach method, would be as follows:

      RA = Total Alkalinity – [Ca in ppm]/1.4 – [Mg in ppm]/1.7

      As an example, my local water profile follows along these lines:

      • Ca – 73 ppm
      • Mg – 8 ppm
      • Na – 32 ppm
      • Cl 28 ppm
      • SO4 – 78 ppm
      • Alkalinity – 177 ppm

      If I calculate my RA, I get a value of roughly 120.

      120.15 = 177 – (73 / 1.4) – (8 / 1.7)

      If I calculate my mash pH using Daniels’ equation, I get a mash pH of roughly 5.98, which is more basic.

      5.8 + (0.028 × [(177 × 0.056) – (73 × 0.04) – (8 × 0.033)]) = 5.988

      Thus, a positive RA value increases the base pH value of 5.8 to 5.98, so I should acidify my mash.

    3. Sulfate-to-Chloride Ratio – The sulfate-to-chloride ratio is not a perfect tool, but it can help the brewer understand the hoppy-to-malty / dryness-to-fullness balance of the end product. Keep in mind, however, that a minimum level of sulfate and chloride concentrations must be present for it to have a noticeable effect.

How to use this information

Step 1: Know your water source, and what to expect from it!

This is very important, as your water composition will vary drastically depending on your household water treatment system (if you have one), the source of your water, the flow rates of the plumbing systems, and even the time of the year. Having up-to-date and accurate information about your water composition will help you create the best beer possible. Either use the data included in this guide, call your utilities provider, or send a sample to a testing company like Ward Labs for analysis.

Step 2: Determine which water profile you wish to use for your beer

Once you’ve established the beer you want to create and identify the beer type, gravity, color, and bitterness, you can then establish which water profile you wish to use. This may be based on the Suggested Water Profile Tables (Appendix A), or a specific profile you create. Keep in mind, it’s perfectly fine to experiment!

Step 3: Calculate the estimated residual alkalinity (RA) of your source water

As discussed previously, the residual alkalinity is an important metric because it helps determine how the hardness and alkalinity of your water interact. This will be used in step 4.

RA = Total Alkalinity – [Ca in ppm]/1.4 – [Mg in ppm]/1.7

Step 4: Adjust your water to fit within the profile selected

Adjust your water by diluting with distilled (DI) or reverse-osmosis (RO) water, replacing your source water with another water, and adding various brewing salts until you meet your ideal water profile (see Appendix A). There are many helpful tools online which can assist in this process, or pick up a copy of Water: A Comprehensive Guide for Brewers to learn more.

Step 5: Begin your brew day by removing chlorine and chloramines from your water

The most practical ways to remove these compounds from your water would be to (1) use a carbon block water filter, (2) pre-boil your water, or (3) pre-treat with potassium metabisulfite (campden tablets).

Step 6: Measure out your brewing salts with a gram scale

Divide the custom salt blend into two dishes by weight, one for the mash water and one for the sparge divided in the same ratio as the water. For example, if you will be using 3 gallons to mash followed by 6 gallons to sparge you should add 1/3 of the salts to the mash, and the rest to the sparge.

Step 7: Mash in by mixing the malt, hot water, and the mash portion of the brewing salts

Wait 5 minutes for the pH reactions to take place, pull a small sample of wort, cool to room temperature in a bowl, and take a pH reading. A pH between 5.6 and 5.2 is optimal at room temperature. Ensure your sample is corrected for temperature.

If the mash pH is on target, let the mash rest as normal (this happens 90%+ of the time). If the mash pH is too high add ¼ tsp of phosphoric acid, stir and take another reading, repeat until the pH is low enough. If the mash pH is too low, add either chalk or baking soda ¼ tsp at a time until the pH is high enough. It would be a good idea to note how much change each addition causes so you can use this information next time.

Step 8: Add the rest of the salt blend to the sparge water, and sparge

Some salts may not dissolve completely in water so it is worth giving the water a stir occasionally to keep them evenly suspended. Complete sparge when pH rises above 5.8, or when runnings drop below a gravity of 1.008.

Step 9: Measure, adjust, repeat

You’ll never learn from this process if you don’t measure, adjust, and repeat. So get to it!

Appendix A – Suggested Water Profile Table


Gravity / Type Color Bitterness Calcium Alkalinity Sulfate Chloride Residual Alkalinity Acidify Mash?*
light lager pale soft (assertive) 50 0-40 0-50 50-100 -60-0 Yes
medium lager pale moderate, assertive 50-75 (75-150) 0-40 (40-80) 50-150 50-100 -60-0 (-30-30) Yes
medium lager amber soft, moderate 50-75 40-120 0-100 50-150 0-60 Maybe
medium lager brown, black soft, moderate 50-75 80-120 0-50 50-150 40-80 No
strong lager amber soft, moderate 50-75 40-80 0-100 50-150 0-60 Maybe
strong lager brown, black soft, moderate 50-100 80-150 0-100 50-100 60-120 No
light ale pale moderate, assertive 50-100 0-80 100-200 50-100 -60-0 Yes
light ale amber soft, moderate 50-150 40-120 100-200 50-100 0-60 Maybe
light ale brown, black moderate, assertive 50-75 80-150 50-150 50-100 30-90 Maybe
medium ale pale soft, moderate 50-100 0-80 0-50 0-100 -30-0 Yes
medium ale pale moderate, assertive 50-150 40-120 100-400 0-100 -30-30 Maybe
medium ale amber moderate, assertive 50-150 40-120 100-300 50-100 0-60 No
medium ale brown, black moderate, assertive 50-75 80-160 50-150 50-150 60-120 No
strong ale pale moderate 50-100 0-40 50-100 50-100 -30-0 Maybe
strong ale amber moderate, assertive 50-100 40-120 50-100 50-150 0-60 No
strong ale brown, black moderate, assertive 50-75 120-200 50-150 50-150 120-200 No

*“Acidify Mash” means to add acid malt, phosphoric acid, or lactic acid to the mash.

Referenced Resources & Recommended Readings

Last updated: 2014-08-12

4 thoughts on “Brewing Water: A Practical Guide for Homebrewers

  1. Just what I was looking for, I always believed that its the water that makes the difference. You can have the best hops but if your water is crap your beer will be crap.

Leave a Reply

Your email address will not be published. Required fields are marked *