Have kettles gone off the boil?

I’m told that gold-plated taps stay shiny and are not affected much by limescale. There are plenty of good solutions to problems if you are prepared to spend a lot.

I have never worried about the noise made by a kettle and the only time it has been messy was when one sprung a leak.

The Qooker delivers boiling water but for a really good cup of tea (or coffee) the rule is don’t boil the water. It should be very hot but not boiling. OK if you’re one of the snobby “milk in first” brigade but then how do you get the strength right?

Why “snobby”?

Firstly, there is no need for pejorative comments – people can make tea any way they please.

Secondly, it was the poor who put their milk in first. They could not afford high-quality bone china. Starting with cold milk causes less of a shock to the cup and it is less likely to crack!

And thirdly, in this household, the butler serves the tea how I like it. It’s not my problem.

…and fourthly, if you suddenly drop cold milk into a mug full of boiling hot tea, the milk scolds. If you poor hot tea onto cold milk, the milk heats more progressively so doesn’t scold.

Although I know that you shouldn’t use boiling water to make the best coffee, I don’t believe that is true for tea. As the wartime government information film demonstrated (yes, governments played trivia even during the war), you should preheat the pot for a minute, add the tea and pour BOILING water onto the tea to make the best cuppa. Also, you should use freshly drawn cold water to fill the kettle and only boil it once (boiling water drives out the dissolved air/oxygen from the water making an inferior cuppa).

There’s nothing snobby about whether milk goes first or last, but I can taste the difference and so can my wife.

The 1941 video is on YouTube if you want a laugh: http://youtu.be/vnvYymrCn4g

I quite like the idea of scolding milk: “What are you thinking of, adding me to boiling hot tea! Don’t do it again!!!” Where can I buy some?

Maybe that’s what people mean when the milk is bad.

Well the Quooker may seem a good idea until you look at the cost. The basic Quooker is £630 before fitting. That’s over 30 kettles which would last 60+ years. How long before the Quooker fails or you replace the kitchen.

The Quooker looks an environmental and financial disaster to me.

@ Em

I feel like a scolded schoolboy again! I meant “scald” of course. You must be an English teacher?

@terfar – No, it just made me smile.

Environmentally, the Quooker draws 10W on standby.

If my maths is correct, that is the same amount of energy as filling up a 2 litre kettle once a day, boiling it, and then leaving it to go completely cold again. And that would be in addition to any energy used to heat the water you draw off.

On the other hand, I suppose you would only use exactly the amount of water you need. An over-filled kettle also wastes energy, but unless you live at home and have a large family to cater for, a Quooker probably uses more energy than a conventional kettle and saucepan arrangement.

I don’t like the idea of having electrical equipment under a sink. No doubt the unit itself is adequately protected but I imagine that most kitchen fitters would put the plug and socket under the sink, at risk of getting wet if there is a plumbing problem.

With the Qooker, the water is heated to 110C, according to the manufacturer’s information. That is less than a pressure cooker (up to 121C) but having a powerful electric heater in a closed container could be fun if the heater did not cut out for any reason.

@EM

Wow, 10W on standby! That’s incredible.

According to the Which? tests, the average 3kW kettle boils a litre of water in 2m20s (140 seconds). That’s approximately 330Wh.

The Quooker is using 240W/day doing nothing. It is certainly wasting the equivalent of 3 mugs of tea per day.

Here’s a video showing how to descale a Qooker.
https://www.youtube.com/watch?v=Bc7bpswqHqY
All you need is a service kit, familiarity with plumbing and electrical systems and to be happy to poke around under the sink. Easily done within hours.

Boiling water in a saucepan provides a useful reminder of how quick and convenient an electric kettle is.

I’m not sure about 100% efficient, if you take into account the rate of cooling due to lack of insulation. I am surprised that insulated kettles have not become standard.

I’ve been experimenting with boiling a single cup of water at a time in a microwave oven recently. I compared the amount of electricity used doing that, against boiling a kettle at the minimum fill of 2 cups and throwing away the other cupful of boiling water. I found that it’s possible to make a saving under certain circumstances. Using cold tap water, it uses about the same amount of energy (the microwave takes twice as long but uses half the power). But if you already have a cupful of tepid water in the kettle, it’s more economical to bring it back to the boil in the microwave than to add a cupful of cold water and boil it in the kettle. (I know you’re not supposed to boil water twice, and I generally don’t, but on some occasions I’m not too bothered about a slight reduction in taste quality.) The main drawback is I can never tell exactly when the water reaches boiling point in the microwave. Sometimes it’s too cold, and other times it’s superheated and starts bubbling furiously as soon as I drop a teabag in it.

@ClintK

Microwave ovens are inefficient, though they are a convenience.

Many new kettles are designed so that you can boil just a single mug of water. We had to wait a long time for that monumental breakthrough in kettle design!

Clint

Are you measuring the power consumption of the microwave oven or using the power output (the figure generally quoted). A kettle is very efficient but a microwave is certainly not. This will depend on model and what is being heated, but as a guide, Wikipedia mentions an efficiency of 64%.

Take care because superheated water can virtually explode if it is heated in a smooth walled container.

That’s a good point. I was looking at the power shown on the front door, which I guess it’s the power output. The power input would then be written on the back of the oven where the mains cable goes in, but I won’t bother as it’s a bit of a hassle moving it. But with a typical efficiency as you quote, it wouldn’t be as economical as a kettle, even though I am boiling only a cup. So I’ll go back to just using the kettle. I know I can buy a kettle with a one-cup minimum fill, but I’ll only do that when the current one breaks, as the expense of a new kettle would outweigh the savings in electricity from only boiling one cup.

Clint

I would not want anyone put off using a microwave oven for its normal purpose since it is more efficient than a conventional oven.

The main power loss in a microwave oven are in the magnetron, which produces microwaves. That gets hot and has to be cooled by a fan.

As you say, the power consumption of a microwave oven will be shown at the back. That will be an estimate of the power used at the highest setting.

Despite my comment, I use my microwave oven for reheating filter coffee – which would spoil if kept hot. Two minutes and twenty two seconds is spot on for a mug of cold coffee.

‘Wavechange

Agreed. Microwaves do have a role to play in the kitchen. For starters, warming a baby’s bottle is so simple – a boon in the middle of the night. They are great for defrosting in a hurry. And reheating many small portions of foods such as left-over rice or a bowl of soup. We would do without ours, but we are very selective what we use it for as often the gas hob is cheaper (if not just as efficient)!

Terfar

Yes, and I am surprised that no-one is promoting old-fashioned kettles on gas hobs. I wouldn’t have one because I don’t like the idea of unflued gas appliances, but (mains) gas is certainly a cheaper way of producing heat.

Em, try real tea (leaves) in an infuser instead of a tea bag if you just want a single cup. Otherwise a tea pot – you can’t beat leaf tea.
Kettles are pretty safe at pouring boiling water – much more risky to use a saucepan or any other open-topped container.
I still find the statistics hard to believe.

You raise some interesting and complex points regarding energy efficiency. Gas boilers are far from 100% efficient whereas the humble electric kettle is almost that. Even if you have a combi boiler, depending on its distance from the kitchen sink tap (the time it takes to bring the water up to temperature and flush the cold from the pipes) using that source for a bowl of hot water is unlikely to scrape 50% efficiency. It is only because gas is so much cheaper per kW than electricity that it becomes cheaper than boiling the kettle. Environmentally, it would be better if we stopped using gas central heating boilers as a source for hot water.

I note that most dishwashers and washing machines are usually cold fill only devices these days. Perhaps if we all used instant electric showers and kettles and stopped using gas to heat water it would benefit the environment (but not the pocket).

Electricity can be converted into heat very efficiently, but what about the efficiency of electricity generation and transmission? The merits of hot/cold fill washing machines have been debated at length in another Conversation. Depending on the plumbing of a house, they could be more or less economical (financially that is).

John is right to highlight the importance of house design for supplying hot water efficiently. I don’t know what regulations apply for new buildings. However good the pipe insulation is, the water in pipes will cool fairly quickly, so a short pipe to the kitchen tap is vital. I’m planning to move home soon and this is one thing I will look at when viewing houses.

I have friends with a large and very expensive kitchen in a huge house. The hot tap is not even connected because the pipe run from the hot water tank would be far too long. Anything that does not go into the dishwasher is washed using water heated in an electric kettle and/or a kettle on the Rayburn.

That sounds right, Terfar. Economy and evironmental performance are frequently at odds. Apart from anything else, having twenty million little boilers [and a few million really big ones for schools, hospitals, office blocks and stores] is not the most efficient way to heat our water or our indoor space. I don’t suppose the grid could cope with the demand if we all converted to electricity at once but a managed change could be devised and new power sources [including gas] brought on stream in harmony with the rise in demand.

On the washing up question, and the waste of water that precedes the arrival of the hot, we don’t really want it at the full heat so letting some cold into the bowl before the hot arrives can usually produce the ideal working temperature and one soon gets to judge how much to use. With the best will in the world, and using the water fill gauge, it is impossible not to boil too much water to make two cups of tea but I usually have a ready use for the excess to wash up a mug or clean out a sauce bottle or something.

It illustrates that we have a very long way to go before we can say we are truly green. All the governments efforts at ‘greening’ and planning for our future energy needs seem pretty futile to me when there is just so much we haven’t done to reduce our existing demands.

Subsidising electric cars to the value of £5000 seems crazy when the same money could be used to make a few homes more energy efficient and make a REAL saving to the environment! Making a home more efficient makes it more comfortable and cheaper for the occupants whilst making a real contribution to reducing energy consumption, reducing environmental pollution and reducing the demand on our limited natural resources. Subsidising electric cars using our current technology will save nothing at best and possibly causes more long-term harm.

The electric kettle will be with us for many more decades yet.

I totally agree with these points, Terfar. The electric car is only green if you choose to ignore some of the most important considerations. Buying an electric car on environmental grounds is about as flawed as spending £1000 on a boiling water tap to save money.

It’s about time that kettles were sold with a 10 year guarantee – both on environmental grounds and to save consumers’ money.

Hmm, there seems to be a problem with “Reply”. Several times now, I’ve noticed my posts are detached from the sub-thread in question.

I am surprised that we hear so much about solar power, both PV and water heating, but little about heat pumps. Perhaps rising fuel prices will make heat pumps a more attractive option, particularly to those using LPG or oil for heating.

I would be very surprised if a plug-in timer would be reliable if used near its maximum capacity. You would be better to use a hard-wired professional grade timer, or have an isolation switch on the circuit.

I cannot provide you with any facts, but think about the consequences of a leak or failure of a boiling water tap and a kettle. Which would be easier and less expensive to deal with?

garry – I think you miss the point of the Quooker if you intend to turn it off at night. They are basically giant extremely efficient thermos flasks with an element. So leaving them on at night means a very slight amount of electricity is used to keep them at boiling point.

Overall I suspect that with two of us at home and drinking tea and coffee morning noon and night whatever the cost is for the overnight electric we wil have more than made up by the amount of exact amounts of water we put in our cups. Boiling excess water in a kettle is very easily done. For five people I would strongly suspect that the Quooker would actually be more efficient than a kettle – capital costs aside.

I think where the Quooker really scores heavily is obviously convenience, but, more importantly to me is the freeing of worksurface. I have mine so that it is by the main tap – a position that no kettle could occupy.

When I recall electric cables and filling the kettle it seems really quite laughably inefficient. I was going to say I would always have one though on reflection if struck for cash I could go for an induction hob and a suitable kettle. Induction hobs boil water very very quickly and you are losing no space. The downside of course being if someone wants a coffee during Sunday lunch preparations!

Incidentally on the space front I bought some Christel pots and pans used with detachable handles which makes for some very efficient space storage. Space in kitchens is finite so paying for efficient space use is not daft.

dieseltaylor wrote: Induction hobs boil water very very quickly…

Earlier you wrote that it took under two and a half minutes to boil half a pint of water. My kettle cost under £30 and will boil this amount of water in under 50 seconds. A gas hob and a good kettle might be even faster, but there must be a reason why electric kettles are so popular.

A good reason to argue against electric kettles is safety. Having a powerful electric heater in a plastic container is a fire hazard. Fortunately, they boil so fast that they are unlikely to be left unattended.

Just for laughs I tried 1pt /20fl ozs in a 20 cm pan and that was 2 minutes for 203F and climbing a a degree a second. It was difficult to be accurate with my hot sugar thermometer as if I touched the base it flipped off. Judging by the amount of steam generated I would think a kettle switches off earlier – though you can imagine the benefits in time if you only warmed to 98C as how many people check the heated water from the kettle.?

Does you kettle double its time for a pint?

This is interesting and at the bottom a film regarding kettle design
http://www.explainthatstuff.com/how-electric-kettles-work.html

Good point. I do think Which? has a tendency to silo products to a particular set of tests.

Going to basics like what is the best/easiest/most efficient/ cheapest way to boil water for tea/coffee/ scalding vegetables etc would mean a more discursive article but one that might even mean coffee machines came out on top!

oh! and a bit about if you have gas or solid fuel how it alters the case.