bmorosco: the very first kit I did i used my tap water. Unfortunately I forgot that we have a water softener. Even worse, I was starting a WE Selection Estate Cab...somewhat costly. I went ahead and finished it to bottling. Well, it's got about 18 months on it now and while it has great aroma, the flavor is just not there. The lack of minerals, etc. really knocked it out. I open a bottle every month to see if anything has changed, but no luck. I'm trying to figure out what to do with it now. Cooking maybe??? All of my other kits I have started I have used either tap water from a faucet that is pre-water softener, or as others do...spring water from WalMart. Live and learn.