In discussing aspects of mazering with fellow Mead Judge classmates, a question has arisen on which there does not seem to be lots of available data. A check of Schramm's book provides only a few lines devoted to water. Not really much on the web either.
So, what type of water is best suited for making mead?
From what I have gleaned, the primary and maybe only factor most mead makers use is pH. If the combination of water and fermenting honey get a pH around 3.8, you don't need to make any changes. Kind of like with extract brewing, if the water is good to drink, then it will make good mead. But what about great mead?
It seems there are some prerequisites for the water profile of mead: Sufficient Ca for yeast health and clarity, sufficient CO3 to offset the gluconic acid produced during fermentation and the low pH of natural honey, the need to keep levels of Na, Cl, and metals in check so not to highlight any off-flavors, and reduction of chlorine/chloramines is a given. It seems that with proper nutrient additions, much of these basic items can be provided, thus killing two birds with one stone.
There has been countless hours of effort devoted to classic brewing cities water profiles for beer production and the various nuances provided by different ions in the brew water. What else is worth worrying about for mead?