🍺 Top-down Brew: EZ But Crude Water Calculator

Purpose: This is a quick but rough calculator to adjust the chemistry of brewing water.

1. Enter the water volume:

gallons or liters

US gallons Metric liters

2. Enter the starting water concentrations in parts per million (ppm):

Calcium (Ca2+)
Magnesium (Mg2+)
Sodium (Na+)
Sulfate (SO4)
Chloride (Cl-)
Carbonate (CO3)

3. Enter the salt additions in teaspoons:

Calcium sulfate (AKA gypsum)
Calcium chloride
Magnesium sulfate (AKA epsom salt)
Sodium chloride (AKA table salt)
Calcium carbonate (AKA chalk)
Sodium bicarbonate (AKA baking soda)

Results: *** Waiting for results ***

Notes

This calculator is for adjusting the mineral concentrations of brewing water. The use teaspoon measurements is quick and easy, but somewhat crude. Use this calculator if you prefer ease-of-use over precision.

The following are some minimum/maximum recommendations (Green (2017) BYO, May-June, p. 84-91):

The calcium and carbonate/bicarbonate levels are arguably the most important. Calcium levels of at least 30 to 50 ppm are needed for the mash sugar conversion process and for yeast health. The carbonate/bicarbonate levels are important for determining the mash pH. High carbonate/bicarbonate levels can pose problems for the mash pH of pale beers.

For most beer styles it is best to begin by adjusting the calcium sulfate and calcium chloride additions. The other possible salts are less essential. Calcium carbonate does not readily dissolve into neutral pH water. It may be useful when added directly to the mash of dark beers like porters and stouts to counteract the acidity of dark malts. Calcium carbonate should be avoided for lightly colored beer styles.

Brad Smith has a nice description of the sulfate-chloride ratio based on John Palmer's research. In brief, ratios of 0.8 to 1.5 are considered balanced. Ratios that are less than .8 (more chloride) enhance maltiness and over 1.5 (more sulfate) emphasize bitterness.

Gordon Strong uses a similar volume-focused (teaspoons) approach with reverse osmosis water (Strong, 2020 March-April, BYO, p. 50-57). Here are his basic suggestions. Keep in mind that reverse osmosis water starts with zero minerals and is adjusted to pH 5.5.