Why tap water tastes so different on holiday – and where you should buy bottled
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I’m currently planning what supplies to take on a family holiday, and the question came up of whether the tap water is OK where we’ll be going – a French island. I reassured my children that the water will absolutely be safe to drink – but it may well taste a little different.
The norms around drinking tap water versus bottled water certainly vary across Europe, as shown by an Italian court case this week. Restaurants were found to have no obligation to provide the free stuff, unlike in the UK.
But in the majority of Europe, municipal water is safe from harmful microbes and chemicals. So, why is it so common to dislike the taste of water from a different region to your home?
Tap water in most developed countries is safe because, whether the source is lakes, rivers or underground aquifers, water providers go to great lengths to remove any physical contaminants and harmful chemicals, and kill any bugs. They also carry out frequent quality tests of the water supply to check that nothing has gone wrong.
Less developed countries don’t have this same infrastructure, and so people are advised to buy bottled water in some places, to cut the risk of travellers’ diarrhoea, or even infections with parasites.
That means not just avoiding water from the tap, but also turning down ice in drinks, as well as raw fruit and vegetables that may have been washed in tap water.
Fruit should be OK if you wash it in bottled water and then peel it yourself. And don’t forget to use bottled water when brushing your teeth.
In the past few years there has been a surge of cases of salmonella and shigella infections in Cape Verde, a group of islands off West Africa. These are suspected to have been caused by contaminated water.
The UK Health Security Agency now advises travellers there to strictly avoid the tap water, and those who have weak immune systems may want to consider asking their doctor if they can take antibiotics out with them, as a precaution.
Regions to avoid drinking tap water
Mexico and the rest of Central and South America
Thailand, Vietnam and most of Asia – except high-income countries such as Japan
Most of Africa
Most of the Middle East
For more detailed information, see the website of the government agency, the National Travel Health Network and Centre.
Why water tastes different
Travellers have much less to worry about if they want to drink the tap water in Europe, North America and Australasia.
But you may find yourself wincing with your first taste. The main reason is that water from different regions has different levels of dissolved minerals, such as calcium, magnesium, silicates and bicarbonates.
“When the water rains down, it trickles through layers of rock and sand, and it picks up properties of those layers. And different minerals impart different flavour and qualities,” said Professor Elena Berg, a biologist at the American University of Paris who is also a water sommelier.
Water’s mineral content is measured as its total dissolved solids (TDS). Typical values for tap water are about 100 to 200 parts per million, while salty sea water is about 30,000.
The taste of water with a TDS that is too low can be just as disconcerting as that of water where the TDS is higher than you’re used to.
My children rediscover this when we visit Edinburgh every summer, where the tap water has a TDS below 50, while we are used to London water with a TDS as high as 350.
Water in the south and east of England has more minerals because it runs through easily dissolvable limestone rocks, while the hard granite landscape of Scotland is less liable to dissolve.
Scottish tourism promoters say Edinburgh water is therefore cleaner tasting – but it really depends on what you’re used to. As a southerner, I find Edinburgh water tastes oddly flat and bland.
You may have noticed other regional peculiarities. For instance, water in the French Alps can have very high TDS values, and some feel it is faintly metallic tasting. The hot water supply in Iceland may have an “eggy” smell, because the volcanic landscape means the water has dissolved hydrogen sulphide.
There may be other reasons that tap water on holiday tastes odd. No matter how good the water when it leaves the treatment plant, if pipes that bring it to your hotel or home are a bit rusty, that can be detectable. If you notice this, it is worth letting the tap run for a few minutes before using the water.
The water processing plant may also use a tad higher dose of chlorine than you’re used to, and it can be off-putting if you detect a residual whiff or taste, although it is completely harmless.
This can be fixed by filling a jug or large bottle with the water, leaving the top off, and letting it rest in the fridge for half a day, which lets the chlorine evaporate.
This has the benefit of cooling the water too, said Berg. “It’s really common that people like their water chilled.” At tasting competitions, though, the water is usually served at room temperature, to enhance the flavour, she added.
Some people may just prefer the taste of their usual brand of bottled water. These are usually made from a single water source, like a spring or aquifer, and so always have the same characteristic blend of dissolved minerals.
A more recent trend is for US firms to start with ordinary municipal tap water, remove all the natural minerals, and then add back their own blend. This is usually called “mineralised” water, rather than mineral water, to signify it has been artificially made. There is no recognised health benefit to doing this, but the companies usually claim it improves the taste.
Bottled water not superior to tap water
Contrary to popular belief, bottled water is not necessarily superior to tap water. In countries like the UK, the tap water supply undergoes so many checks for chemical or microbial contamination that experts generally say it is safer.
In a Yale University ranking of different countries’ tap water safety, “UK drinking water is amongst the highest in the world”, said a spokesperson for the water safety agency, the Drinking Water Inspectorate.
All the common tourist destinations within Europe, such as France, Spain and Italy, score similarly well in the Yale University ranking.
If a concern is “forever chemicals” from plastics, like PFAS, recent studies have shown these are at very low levels in drinking water in the first two regions of the UK that have been studied. Their levels in water supplied in plastic bottles are unclear.
But it seems unlikely that people will be dissuaded from buying bottled water. About a fifth of the UK consumes this rather than tap water; sales of bottled water have been nudging up by about 5 per cent a year and are showing no signs of slowing.
People can reduce the environmental impact of their bottled mineral water by trying to buy it from local sources, so it hasn’t been transported long distances. “We shouldn’t be importing this heavy water, and heavy glass bottles,” Berg said. “We should really be appreciating our local water sources.”
I’ve also written
Could we have misunderstood why junk food is bad for us all along? Processed food, like ready meals and snacks, is usually seen as unhealthy because of its high fat and sugar content and artificial ingredients. But the real reason could be that processed food tends to be softer, and so is eaten more quickly than its whole-food equivalents.
I’ve been watching
It is over twenty years since it first aired, but I’ve been enjoying rewatching the US sitcom Arrested Development, currently on Netflix. The first three series were widely acclaimed as a masterclass in comedy, and I’m reminded how much they deserve this status with nearly every episode.
The question is whether I dare watch for the first time the last two series, when the show was resurrected after a long hiatus.
