Water Chemistry Part 2 of 2: CaCO3 & pH
In Part 1 of this topic I mentioned how minerals like Calcium and Magnesium contribute to healthy fermentation, clarity and flavor stability. Here, in Part II, we’ll identify the ideal concentrations of each, address brewing salt additions and explore the effects of pH and alkalinity on your mash conversion. Finally, I’ll explain how to use different ratios of chloride to sulfate to accentuate certain ingredients in your recipe.
Remember, hardness (expressed on your water report as “Total Hardness as CaCO3”) is not a bad word in brewing. Calcium and magnesium are the two main ions that contribute to hardness. Both are necessary for yeast health. Calcium is also responsible for helping to promote enzymatic activity in your mash as well as other biochemical reactions. The optimal brewing water range for Calcium is 50-150 ppm and for Magnesium, 10-30 ppm. Magnesium additions are seldom needed as malt usually contributes enough magnesium to reach these ideal concentrations.
There are several great (and free!) brewing water calculators available online. Start by inputting your own water’s data and then adjust to these ideal ranges as needed. If your calcium concentrations are lower than the ideal range, just a few grams of Gypsum (Calcium Sulfate) or Calcium Chloride can make a big difference. Be aware of the other ion in each compound (sulfate and chloride) as these concentrations will also be affected. If your concentrations are higher, you might consider cutting your water source with distilled, deionized or reverse osmosis water. A 1:1 dilution will cut your concentrations in half. In most cases, this should get you within an acceptable range for brewing.