Researchers tested whether consumers could tell the difference between bottled water and tap water, and guess what? Most people can't.

A French research team ran a taste test of six different bottled mineral waters and six municipal tap waters.  The 389 tasters came from all over France.  The bottled waters were "chosen among the French bottled water available". The tap waters were "from various regions of France, supplied by Lyonnaise des Eaux". The research was a collaboration between two scientific institutes (CNRS, the French National Centre for Scientific Research, and INRA, the National Institute of Agronomic Research) and Lyonnaise des Eaux, a company that manages many public water supplies. The team published their study in the Journal of Sensory Studies in 2010.

The report concludes "most consumers cannot distinguish between bottled water and tap water when the latter is chlorine-free".

Five years earlier, in Belfast, Deborah Wells had run a similar test, with slightly more than 1,000 people tasting water from several sources. These included "one of the UK's most popular brands of still bottled mineral water (Evian, Danone Waters), distilled water (supplied by Queen's University Belfast), and tap water (supplied to Belfast by the Water Service from the Silent Valley, Co. Down)".

"The findings from this study indicate that people cannot correctly identify bottled water on the basis of its flavour," she declares. This "suggests that the currently high consumer demand for this beverage must be based on factors other than taste or olfactory perception".