Water is essential to all life on Earth. Beer is over 80 percent water. Needless to say we are glad we have it, but what choices do we have to make about the water that goes into our beer? Most water is rarely completely pure, but often has a large number of things disolved in it.

There are a handful of ions relevant to the brewing process. There are ions that affect the mash chemistry either by buffering or altering the pH. Some ions are necessary cofactors for mash enzyme activity.

Table 1: Some notable ions in brewing water and how each ion effects mash chemistry, fermentation, and on the flavor of finished beer. Some less important effects were omitted for clarity.
Ion Mash Fermentation Finished Beer
Calcium Lowers pH. Needed for enzymatic activity Essential nutrient for yeast metabolism
Magnesium Lowers pH Essential nutrient for yeast cell division Enhances flavor at low concentrations
Sodium Salty flavor creates perception of roundness
Carbonates Buffers the acidity from dark grains
Chloride Very weakly basic
Sulfate Weakly basic Enhances hop bitterness
Table 2: Various salts can be used to modify the ion concentrations in water used for brewing. This table shows the contribution in parts per million (ppm) of 1 gram of each salt disolved into 1 gallon of water. It should be noted that chalk has very low solubility at neutral pH and more easily dissolves in the mash solution which is slightly acidic. Values for kosher salt and chalk from Noonan [1], Values for baking soda from Palmer [2], all other values from morebeer.com [3].
Salt Formula Ca2+ Mg2+ Na+ HCO3 Cl SO42–
Baking Soda NaHCO3 75 191
Burton Salts (mixture) 44 11 27 105
Calcium Chloride CaCl2 72 128
Chalk CaCO4 105 158
Epsom Salt MgSO4 26 103
Gypsum CaSO4 62 148
Kosher Salt NaCl 110 170


  1. ^Noonan, Gregory. 1986. Brewing Lager Beer. Boulder: Brewer's Publications.
  2. ^Palmer, John. "15.4 Using Salts for Brewing Water Adjustment." How to Brew. Retrieved 2012-12-19. http://www.howtobrew.com/section3/chapter15-4.html
  3. ^Morebeer.com. Retrieved 2012-12-19. http://morebeer.com/search?search=salt