I think distilled water has become a marketing name rather than a technical name. If you read the fine print on the bottle, some that say distilled water in large print will say in small print something like "produced by xxxxxx method" - where that could be distilling, ultrafiltration, or reverse osmosis, maybe even a few other things, or maybe a multi-step method. I suspect is has to meet some final spec, and they get away with using whatever method they can that meets the final spec for distilled water, if there is one. I'm not saying the water isn't good, I'm just saying you have to be careful about generalizing what may be in it based on your notion of how you think they make it.