Can people perceive the difference between bottled water and tap water? Two studies suggest that – at least in France and in Northern Ireland – water tastes like water.

A French research team ran a taste test of six different bottled mineral waters and six municipal tap waters. This 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 tasters were "389 persons 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 team published their study in the Journal of Sensory Studies in 2010.

The researchers identified what they call the "three main tastes of water" that can be found if one swigs a great variety of bottled and tap waters. These are "the bitterness of poor mineralised water, the neutral taste (associated with coolness) of water with medium mineralisation and the saltiness and astringency of highly mineralised water."

The report concludes that "most consumers cannot distinguish between bottled water and tap water when the latter is chlorine-free". (But most is not all. The report goes on to say: "However, 36% of the subjects were found able to distinguish between tap water and bottled water.")

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)".

Wells, a senior lecturer in psychology at Queen's University, then wrote a report called The Identification and Perception of Bottled Water, which appeared in the journal Perception.

"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".

That thought was not entirely new.

The previous year, we awarded an Ig Nobel prize in chemistry to the Coca-Cola Company of Great Britain. The company has long publicised the existence of a "secret formula" for its signature cola beverage. The key ingredient is water.

But that's not what won them the prize.

They were honoured for using advanced technology (mostly pumps) to convert ordinary tap water (obtained from Thames Water, in Sidcup) into Dasani, a pricey, water-filled bottle. It sold briskly – until news broke that Dasani was just bottled tap water.

But ... it wasn't "just" bottled tap water. As the Guardian reported on 20 March 2004: "The entire UK supply of Dasani was pulled off the shelves because it has been contaminated with bromate, a cancer-causing chemical."

• Marc Abrahams is editor of the bimonthly Annals of Improbable Research and organiser of the Ig Nobel prize