True …calcium hydroxide or calcium carbonate …but I chose a while back to simplify my approach to brewing.
Oh, I had a box full of all the salts I ‘needed’ to brew to style. (sodium metabisulfate, calcium hydroxide, calcium carbonate, calcium chloride, calcium sulfate, magnesium sulfate, sodium chloride, sodium bicarbonate, ….).
I followed water recipes from all different sources. Used various spreadsheets. Fiddling with this only to throw that off and adjust here to screw up something over there. None of the spreadsheets agreed. None of the experts agree. Mash pH was all over the map. I had to add acids or lime to control it. And on, and on. Like a dog chasin’ his tail. But bottom line: I thought the beers sucked.
So, I gave up all that crap, quit spending so much time and concern about what water was supposed to be for certain styles, and chose one simple method. This move was influenced heavily by G Strong’s book Brewing Better Beer.
I choose to restrict myself to use of the two (CaCl and gypsum) for very specific reasons, alone or in combination, in RO water to get me where I want to go. I traded in time spent on spreadsheets, the confusion, the box full of salts, and meticulously measuring them on a gram scale for a set of teaspoons and BeerSmith’s water module to report ppm. It is 10x less PITA.
Admittedly, it might not be for everyone, but I sure like the outcome and it’s so much easier for me. Bottom line: the beers don’t suck.
(Sorry for high jacking your thread Tommy).
Disclaimer: Any comment I add is simply the way I brew beer. I am not paid or sponsored by anyone. There are certainly other ways that can be equally effective which other brewers may contribute. This is what I’ve found that works for me using my equipment and processes so I offer this for your consideration. YMMV