Minerals can theoretically be added to distilled water, but you can only market bottles as ‘natural mineral water’ if the mineralization occurs organically in aquifers. Water picks up its mix of minerals as it seeps through layers of rock on its way from the earth’s surface to underground streams.

While you may decant the sourced water to filter out undesirable chemicals such as iron and arsenic, your production process may not add any minerals further to it.