/ Food & Drink, Home & Energy

Why kettle water tastes funny: mystery (nearly) solved

Steaming red kettle

Earlier this year we asked you to help solve the mystery of smelly, foul-tasting kettle water – a problem that for many of you has been spoiling your daily cuppa. And now we’ve discovered a common cause.

The problem bubbled up when Which? members complained that the water heated in their kettle had a ‘plastic flavour that made it undrinkable’. We carried out testing in our lab, which confirmed there was a problem with how the water in one of the kettles tasted and smelled.

But it soon turned out to be far from an isolated problem. In fact, we’ve so far had more than 130 comments complaining about the taste and smell of the boiling water your kettle produced.

But what’s the cause? It soon turned out that it wasn’t a single brand that was to blame. Was it the water supply? Even some of you who used filtered water had the same problem.

The cause of smelly kettle water

We contacted scientists Luke Montgomery of Yorkshire Water and Dr Robin Price of Anglian Water. They told us that the chlorine in tap water reacts with phenol-based compounds sometimes found in plastic and rubber parts of the kettle.

There aren’t any associated health risks. And not everyone will have this problem – chlorine levels vary, and people have different sensitivities to taste and smell, Dr Price told us.

It’s recommended you compare the kettle water with water boiled in a saucepan to see whether it’s the kettle’s causing the problem. If it is, you can get rid of the chlorine by storing tap water in a covered jug in the fridge for a few hours.

We’re looking into whether in the future we can test every kettle we review for this problem, so you can avoid buying models likely to produce smelly water.

However, the mystery still isn’t fully solved. We had problems with the Russell Hobbs’ Ebony 15076 kettle even with filtered water that didn’t contain any chlorine.

Comments
Guest
Mountain Man says:
12 April 2017

My new Russell Hobbs ‘Cambridge 20071’ kettle boils up smelly water. Smells and tastes a bit like chlorine or bromine.
Before first use, I removed 2 plastic components: the red water-level indicator tab from inside the kettle; and also the plastic spout-screen.
That just leaves 2 plastic components: the black plastic lid; and the inside top anchor for the black plastic handle.
The rest of the kettle is all stainless-steel (no water level window on that model).
My cold water supply does not smell, and does not cause furring. Water is a municipal supply from a surface catchment area).
This new kettle replaces a 15-year-old white all-plastic kettle, that had no smell nor taste.
I have tried to get rid of the smell by boiling fresh water, and then discarding the smelly water; done this perhaps 20-times. And I’ve washed the black plastic lid in the dishwasher several times.
I see (on the internet) that this problem has been publicised since 2013. How come Russell Hobbs hasn’t been able to fix this in the intervening 4-years?

Guest

I purchased same kettle – same problems – tried washing, re boiling etc – nothing helped. I used it for about 3 weeks and also developed a pain in kidneys ( I have no health issues) – I purchased a BPA free kettle – all fine and after a couple of weeks kidney pain gone …is there a connection – very strange but happy with new non smelly kettle

Guest

Hi Fi – I remember you saying in another Conversation that you bought an all-stainless steel kettle and giving us the details. What you say here suggests that your previous kettle contained BPA. Is there evidence of this? Normally BPA is associated with polycarbonate and I don’t think the black plastic used in many kettles is polycarbonate.

Guest
Dave Tattam says:
20 May 2017

We purchased a new digital kettle from Aldi 2 weeks ago,a Ambiano premium digital kettle,The cup of tea/coffee tastes of chemical from the time we first used it,we boil water for tea/coffee in a saucepan and it tastes fine.What should we do?

Guest

Take it back as unfit for purpose?

Guest

As Alfa says, take it back. It’s sometimes suggested that sodium bicarbonate (baking soda) might help get rid of smells and tastes.

I wonder if my kettle is digital. The switch is marked 0 and 1.

Guest

I have just bought a new stainless steel Bosch kettle that is exclusive to John Lewis and am pleased to report there is no unpleasant taste.

Apart from the filter and maybe a very small seal, there is no other plastic on the inside.

Guest

Bosch kettles seem to be a good bet for anyone who is frustrated by the problem of strange smells and tastes.

Guest

A small seal, you say? Not a dolphin? 🙂

Sorry….

Guest

Sorry? You said that on porpoise. 🐬

Guest

Oh, you’re having a whale of a time…

Guest

Mind you, it might just have been a fluke…

Guest

Life’s a drag, isn’t it Alfa? You buy a brand new kettle and there isn’t a Which? Connect survey on hand to ask you why you bought it, whether you had tried to repair the old one, what it smelt like, what it tasted of, and whether you would recommend your mother-in-law to get one.

Guest

🙂
We’ve made several trips to look for a new kettle since the last one caught fire, using the previous one with a broken lid kept as a spare.

Most of them as so darned ugly which is why it has taken a while. The one we have bought wasn’t even on show and we had given up again but espied the box on the lower shelf. At last a kettle that (to us anyway) looks normal and pleasing to the eye. As others have reviewed, it is a bit on the noisy side, but hey it’s only on for a couple of minutes so not much to put up with.

Guest
Paul m says:
11 December 2017

Hi Alfa; can you tell me what the model is please? I am havg to return my third kettle in a row on account of the smell!

Guest

This one Paul, only available in JL.
https://www.johnlewis.com/bosch-town-twk78a01gb-stainless-steel-kettle-silver/p2963731

I don’t have a problem with the level indicator maybe because the kettle is in a well-lit position.

I still like it and don’t regret buying it.

Guest

I have noticed very few complaints about strange smell or taste for Bosch kettles.

I had assumed it was all stainless steel but from one of the reviews, the lid seems to be plastic: “Had this kettle for about a year now and for the last couple of months I have found that after it’s boiled I cannot open the lid to refill it again until it has cooled down as the plastic lid expands with the heat! “

Guest

We bought a Riussell Hobbs “Dome” polished kettle to replace our old R/Hobbs that recently developed an unreliable switch. A Which? best buy, £30 from ao delivered free. No taint, quiet, fairly quick to boil, pours well, easy to fill……:-)

Guest
Phil T says:
3 January 2018

I have the same Russell Hobbs kettle you describe. Steel lid but does have a water level window. Had a filter which I of course pulled out. Its an electric kettle that I do not fill from streams or outside water tubs.

When limescale inevitably begins to build up half fill your kettle with water and a chopped up whole lemon. Boil it a few times or boil it and put something on the on/off switch to make it stay on and let it boil for a few minutes.
Discard contents when it cools and give it a rinse the inside will look something like it did whan it was new.

I do this with new kettles anyway. I might be a good idea and its not a bad one.

Guest
Alan Roberts says:
3 January 2018

Have experienced this problem for years.. It definitely occurs when you add fresh water to previously boiled. Recently bought a filter kettle, same happened. I’ve just done an experiment using a saucepan. I boiled water, let it partially cool, added fresh water, boiled it again, the awful taste was there. Water company chemists – tell us what is happening ?? You can’t fob us off with it being the fault of the kettle anymore !! It’s such a waste of water and energy to have to empty the kettle and fill it again before re- boiling.

Guest

That might indeed be so, Alan, but it has always been the best advice. Obviously, it helps reduce waste if only the required amount [plus a little bit more] is put in the kettle in the first place.

It’s incredible that, so far as I can recall, no one else has mentioned mixing pre-boiled and fresh water as the source of the problem. That could be why we have never experienced the problem despite a wide variety of kettles having been used over the years as we always empty the kettle and refill it rather than top it up. As you say, it would be nice to have a scientific explanation.

Guest

All the things added to water to make it”safe” to drink could be the reason ?

Guest

In the introduction to this Convo, Paul Ryan explains that reaction of chlorine with plastics is a problem, so if you get rid of plastics that should solve the problem. There would still be the odd kettle that produces hot water with a metallic taste, but this seems relatively uncommon.

It might help to create a demand for kettles without any plastic parts in contact with the water.

Guest

Chlorine may be an answer; this would be easy to prove. Simply use chlorinated “test water” when Which? (and manufacturers) evaluate kettles to see if the water becomes tainted. Then use the “right” plastics in their construction if one type proves a cause. I’d like to see demonstrable cause(s) rather than conjecture. That would help develop better products on a sound basis.

Guest

Alan’s saucepan experiment above seems to shows that sometimes this problem is down to the mains water, and not the use of plastic parts in the kettle (or saucepan used).

Also, long standing good practice for tea making includes the advice “always use freshly drawn water”.

Guest

The well known plastics generally contain a variety of additives such as plasticisers, fillers and stabilisers and no-one other than the manufacturer will know what a particular batch of plastic contains. Age may be a factor too. When a plastic kettle is new, plasticisers and other volatile chemicals are more likely to be transferred to the water. I dug out an old travel kettle that had been stored unused in a clean, dry place for over 12 years. In storage the plastic had yellowed and each time I boiled water it had a musty smell.

All tap water is chlorinated by law and I expect that Which? testing does use tap water. I’m not sure how much help we can expect from manufacturers. Here’s an old article that suggests that RH would be looking at the concerns of Which? http://www.dailymail.co.uk/femail/article-3080577/As-mystery-whiff-spoils-nations-cuppas-thats-making-kettle-pong.html The advice on the website remains to put kettles through the descale procedure if you have a problem.

We still have not established some simple facts, such as whether some people detect a strange taste and others don’t. Different ability to detect certain smells/tastes can have a genetic basis, and some cases are well documented.

It would be interesting to know if any users of all-stainless steel kettles have a problem.

Guest

We have very different tastes – some cannot stand Brussels sprouts for example, and our sensitivity to taste varies considerable. Chlorine concentration differs across the country. NJo one seems to have analysed chemically what is in tainted kettle water. If it were a problem of sufficient magnitude this is where I would start – controlled water and proper tests. Until then we’ll just carry on boiling.

Guest

Given Alan’s results from a saucepan, I’d expect that he would get the same outcome from an all stainless steel kettle.

Then again, unexpected outcomes are part of the fun of doing science experiments.

Guest

Malcolm – The taste of sprouts is one of the examples I had in mind: http://www.nature.com/news/2006/060918/full/news060918-1.html The ability to smell cyanide is even more clear cut.

Guest

The first thing you do is to question and test one-off observations.

Guest
Susan B says:
5 January 2018

I had this problem with 3 kettles in a row, all of which I returned. I now have a hot water tap with a filter. Delicious hot water at the press of a button. My favourite kitchen addition 🙂