jhub1353 wrote:Hello Everyone,
I am starting to brew and don't have quite hard enough water to brew what I want. Does anyone know if Gypsum can be purchased at any chain grocery or chain specialty food store? There are only a few brewing places somewhat nearby, and am trying to avoid buying online. Thank you!
You are probably surrounded by gypsum on five sides as you read this. The wallboard in your house is made of it. You can also get it at your hardware store as Plaster of Paris which you can turn into gypsum by mixing with a little water and, after the mess hardens, grinding to powder. My LHBS was once sold out of gypsum (a local commercial brewer bought him out) and I had to brew so I bought plaster of paris at the hardware store but couldn't quite bring myself to putting this stuff in my beer because I had no idea what else might be in it (I always fancy it's mercury) and had some overnighted (shipping 5 times more than the gypsum was worth). And you wouldn't want to grind up sheetrock either - especially the high sulfur Chinese stuff that's been in the news recently.
So where to get it. It's pretty plain from a little poking around on the net that a homebrew supply shop is the place you will most likely find it but you might be able to find it in an asian market where it will probably be labeled as terra alba (white earth) or, more likely, in some asian script you will be unable to read so you will probably have to ask. Tell them it's the stuff used to coagulate tofu.
You also might be able to find it is gourmet food stores (both because it's used in oriental cooking and because it is used in baking) and perhaps your pharmacist might have some (though I don't think pharmacists do much compounding any more).
Finally, if you are just starting out I assume you are using extracts in which case you do not need to add gypsum (or anything else) to your water even if it is quite soft. The critical reactions that require calcium have already taken place at the factory where the syrup was produced. There are lots of things to learn about before you start making water adjustments.