I get all my drinking/cooking water from the machine in the grocery store. While I'm filling up my 5 gal. plastic water bottles I read on the label that it's basically filtered, reverse osmosis water (as I expected). But the final step is what they call "UV sterilization" which was probably defined by the marketing guys. I'm just thinking, if I sanitized my container first, this grocery store water is probably just as good for adding to wort after the boil as my current method using boiled then refrigerated water.