Brewer's Notes
pH in Strike Water, Mash and Boil Kettle
I have swapped over entirely to R/O (reverse osmosis) water, which requires me to add back in certain ions to achieve good tasting water and beer. The largest requirement is calcium, through the careful additions of calcium chloride (CaCl2) or powdered gypsum (CaSO4) to acidify the liquor and mash.