I've always heard that you need 50ppm calcium in your brewing water to produce good beer. I've read it in the water book and on this forum, but I've never heard the genesis story of this heuristic. Does anyone know? (seriously, not just a question that serves a rhetorical purpose)
Not having 50ppm calcium can cause:
* Your mash not to convert
* Your beer not to ferment
* Your finished beer not to clarify
I know I've brewed beers using < 50ppm calcium and I think that I could brew with distilled water.
Before doing any sort of experiment with a full batch of beer, I figured I should first try to determine if a mash would convert using distilled water. I knew I wanted to take a gravity reading, and I also knew that my hydrometer tube is ~200mL, so I started with 300mL distilled water. I added 150g grain to keep to roughly 1qt/lb.
I wrote up this little test here: http://www.tylercipriani.com/brewing/distilled-water-conversion/
**tl;dr**: The mash _did_ convert...eventually.
I want to try some 1 gallon experiments using 0ppm calcium (distilled), ~25ppm calcium and 50ppm calcium waters and monitor their mash, starting gravity, final gravity, fermentation, clarification and, ultimately, flavor.
Thoughts? Anyone besides me think it's a cool idea?