Finally….I get the water thing figured out thanks to my German brewing books I am using in my M.Sc. studies. Gotta love that German know-how….Here is what you do……. from your water report, take the Alkalinity value, the Calcium value and the Magnesium value. Start by calculating your Effective Hardness which is Calcium (ppm) / 1.4. Next, take Mg / 1.7. Add these 2 figures to get Effective Hardness. Subtract the Effective Hardness from Alkalinity to get Residual Alkalinity (RA). A nicely balanced water will have RA of about 40-50. If your RA is above that, you run the risk of making a distilled spirit where the taste is blaaaah and un-balanced. Let’s take some actual values from a real situation at a craft distillery in the south part of the Okanagan in BC (name withheld for privacy). The local water has Ca of 18 ppm, Mg 34 and Alkalinity 238 ppm. So, 238 minus [(18/1.4) + (34/1.7)] = 205. This water is not exactly the most balanced and could very easily interfere with flavor balance on a distilled product. Plus, the Calcium to way to low for making sure the yeast can function. This distillery (last time I checked) was adding Gypsum to up their Calcium to 100 ppm. At 100 ppm, the new RA becomes 238 – [(100/1.4) + (34/1.7)] = 146. Better, but still not balanced. What this distillery can do (could do?…should do ??) is a novel approach that involves adding a 25 kg bag of Chocolate Malt to every mash. The acidity of the Chocolate Malt grains will be offset by the RA (residual alkalinity) and their distiller will likely notice a significant improvement in distillate flavor and an improvement in taste complexity. And, of course, their distiller will be adding acid to reduce the high pH of his water. There are 2 approaches for this – (1) add actual acid or (2) add a couple pails of the leftover liquid from a distillation run to his next mash. This leftover stillage is highly acidic. This method is what the Kentucky Bourbon makers call the Sour Mash method.