I think the jury is out when it comes to whether it works as a mild chelator, or not. Perhaps it is recipe-dependent? When our last house had somewhat hard water, I noticed less soap scum from the soaps with vinegar, when comparing with those that did not have vinegar. So my experience is anecdotal at best, but seems to be shared by a few other soapers, as well.I see, I thought that website I mentioned said vinegar is not a chelator. Is it more like a sort of almost chelator? You've definitely noticed the difference when incorporating vinegar though? Thank you!