# Microwave vs electric kettle **URL:** \ **Category:** Factual Questions\ **Created:** [February 23, 2020, 8:11pm UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406 "2020-02-23T20:11:05Z")\ **Posts on this page:** 19\ **Page:** 2
**Author:** ![GreenWyvern](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/greenwyvern/32/2834_2.png) [@GreenWyvern](https://boards.straightdope.com/u/GreenWyvern)\ **Post date:** [February 25, 2020, 4:59am UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/21 "2020-02-25T04:59:01Z")
> [@psychonaut](#): > > Another factor that needs consideration is the amount of water you need to boil. Most modern electric kettles I’ve seen have a “minimum fill” line at around 500 ml. If you’re just making a drink for yourself, that’s probably twice as much water as you need, so the efficiency of the kettle is effectively halved. Modern kettles with a flat heating plate at the bottom, rather than an exposed heating element, can heat a very small quantity of water. My kettle has a 500ml minimum line, but that’s only to try to make it idiot-proof. I just boiled 200ml with no problem. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [February 25, 2020, 7:14am UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/22 "2020-02-25T07:14:32Z")
My kettle has a one-cup minimum. But I would never use it to make cocoa. _That_ is done by heating milk and a Mars bar together in a saucepan. ---
**Author:** ![EdelweissPirate](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@EdelweissPirate](https://boards.straightdope.com/u/EdelweissPirate)\ **Post date:** [February 25, 2020, 8:37am UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/23 "2020-02-25T08:37:21Z")
> [@psychonaut](#): > > We have an induction stove and it it heats water even faster than our electric kettle (which I believe is also based on induction). It probably isn’t—resistive heating elements are really well suited to electric kettles—but maybe yours is an outlier. Why do you suspect it’s inductive? My induction hob boils water in my tiny Lodge cast-iron pot (~1 cup) in less than 30 seconds. That’s at 1800 watts with 250 ml of water out of the tap at about 130° F / 55°C prior to turning on the hob. > [@psychonaut](#): > > I think the efficiency of a stove is going to vary greatly according to whether it’s gas, electric, induction, etc., and also the material and thickness of the pot. Absolutely. Generally, the more direct you are, the better. If you’re trying to boil water, it’s hard to beat immersed resistive heaters. ---
**Author:** ![nelliebly](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nelliebly/32/5422_2.png) [@nelliebly](https://boards.straightdope.com/u/nelliebly)\ **Post date:** [February 25, 2020, 8:39am UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/24 "2020-02-25T08:39:51Z")
Is an electric kettle faster than a Keurig? The kettle is undoubtedly better for the environment even if you use a refillable pod in the Keurig. Just curious. ---
**Author:** ![psychonaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/psychonaut/32/4655_2.png) [@psychonaut](https://boards.straightdope.com/u/psychonaut)\ **Post date:** [February 25, 2020, 9:11am UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/25 "2020-02-25T09:11:03Z")
> [@EdelweissPirate](#): > > It probably isn’t—resistive heating elements are really well suited to electric kettles—but maybe yours is an outlier. Why do you suspect it’s inductive? Only because it’s faster than any kettle we’ve ever had, and almost as fast as the induction stove. Admittedly not very sound reasoning, so maybe you’re right that it’s resistive and just uses a lot of power. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [February 25, 2020, 12:03pm UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/26 "2020-02-25T12:03:42Z")
> [@DPRK](#): > > Sure. And if your kettle used 3000 W instead of the 1200W model they tested, it would be even more efficient, because the water would boil much faster. That’s like saying driving at 80 MPH instead of 55 MPH saves gas because you get there faster. You need to add a fixed amount of energy to a fixed volume of water to boil it. Increasing the power of the heater to make it faster doesn’t make it more efficient, because it is consuming the energy faster. If the 1200W kettle needs 2 minutes, then the 3000W kettle would need 0.8 minutes, and their efficiency is probably about equal. Electric appliances that produce heat are very high efficiency because all of the energy goes into producing the heat. Heat is not a wasteful by-product, it\* is\* the product. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [February 25, 2020, 12:27pm UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/27 "2020-02-25T12:27:39Z")
Hot water cools off, though, by losing heat to the environment, the longer it has to sit in the kettle. All that is wasted energy. I’m not claiming it is an enormous difference. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [February 25, 2020, 12:33pm UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/28 "2020-02-25T12:33:55Z")
> [@psychonaut](#): > > But reboiling water is something you should never do if you care at all about how your tea tastes. People seem to disagree whether this is due to the loss of dissolved gases or the concentration of dissolved solids, but either way, the tea ends up not tasting as good. :dubious: Has this been confirmed in blind taste tests? Because it seems unlikely. Concentration of dissolved solids shouldn’t be an issue unless you’re boiling the water long enough to evaporate substantial amounts of it, and near-boiling water will have very little dissolved gases in it, regardless of whether it’s the first or second time it’s been boiled. [Just found this:](https://www.cooksillustrated.com/how_tos/6697-reboiling-water-for-tea) a blind taste test showed no difference in flavor. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [February 25, 2020, 12:39pm UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/29 "2020-02-25T12:39:07Z")
> [@CookingWithGas](#): > > That’s like saying driving at 80 MPH instead of 55 MPH saves gas because you get there faster. No, it’s like saying that accelerating from 0 to 80 rapidly saves gas (compared to accelerating from 0-80 slowly) because you spend less time losing energy due to drag. The more time your pot of water spends at a temperature above ambient, the more energy it pisses away to the environment. So, all else being equal, if the pot of water is heated more quickly, you’ll waste less energy. ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [February 25, 2020, 12:42pm UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/30 "2020-02-25T12:42:34Z")
In this area at least, electricity is more expensive than gas, so the most economically efficient means would be to heat the water on a gas burner. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [February 25, 2020, 12:43pm UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/31 "2020-02-25T12:43:08Z")
> [@Banksiaman](#): > > An average kettle (we call them jugs in these here parts) … Coincidence time: Just last night we were watching an episode of the NZ show _The Brokenwood Mysteries_ where an older character said he was going to put a jug on. From context I figured it meant making tea. Watch a lot of UK, Aus, NZ, etc. shows and this may be the first time I heard this. Then I read this thread and here it is again. ---
**Author:** ![psychonaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/psychonaut/32/4655_2.png) [@psychonaut](https://boards.straightdope.com/u/psychonaut)\ **Post date:** [February 25, 2020, 12:50pm UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/32 "2020-02-25T12:50:40Z")
> [@Machine\_Elf](#): > > :dubious: Has this been confirmed in blind taste tests? Because it seems unlikely. Concentration of dissolved solids shouldn’t be an issue unless you’re boiling the water long enough to evaporate substantial amounts of it, and near-boiling water will have very little dissolved gases in it, regardless of whether it’s the first or second time it’s been boiled. > > [Just found this:](https://www.cooksillustrated.com/how_tos/6697-reboiling-water-for-tea) a blind taste test showed no difference in flavor. There’s also [a Q&A article in _New Scientist_](https://www.newscientist.com/article/mg15420808-100-the-last-word/) that reports that some people can indeed tell the difference in blind taste tests. It’s argued that the hardness of the water and the length of the boil may determine whether the difference is detectable. (I suppose this can be significant for those in hard-water areas who use thermostat-controlled tea urns.) Here’s an excerpt from the article: > [@](#): > > My father was a tea taster and faultless at detecting whether we had boiled the water for too long. How did he do it? > > Hard waters (and most waters do have some mineral salts in solution causing hardening) brew slower than soft or alkaline waters. If you boil hard water for considerably longer than the standard half a minute or so, more of the dissolved salts deposit themselves on the inside of the kettle. The emerging water is then softer than expected and softer than the tea taster balanced the tea blend for. It will brew quicker and with a darker colour than usual. ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [February 25, 2020, 2:10pm UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/33 "2020-02-25T14:10:37Z")
> [@GreenWyvern](#): > > Modern kettles with a flat heating plate at the bottom, rather than an exposed heating element, can heat a very small quantity of water. My Hamilton Beach [electric kettle](https://www.amazon.com/Hamilton-Beach-40998-Electric-Kettle/dp/B00ZPN3O2I) is roughly the size and shape of a coffee percolator. The heating element is built into the bottom of the kettle and it sits on a base with contacts and a switch on it. That way you’re not dragging a cord around when pouring. It’s claimed to be faster than a microwave but I’ve not timed it. It’s certainly handier to load the kettle, flick the switch, then prepare the cup of whatever while the water’s heating. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [February 27, 2020, 6:19pm UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/34 "2020-02-27T18:19:35Z")
> [@Machine\_Elf](#): > > No, it’s like saying that accelerating from 0 to 80 rapidly saves gas (compared to accelerating from 0-80 slowly) because you spend less time losing energy due to drag. > > The more time your pot of water spends at a temperature above ambient, the more energy it pisses away to the environment. So, all else being equal, if the pot of water is heated more quickly, you’ll waste less energy. I agree that’s true, although the greatest heat loss rate occurs when the pot reaches the maximum temperature. I don’t have the numbers but the difference in heat loss during heating is probably negligible compared to the heat added to bring it to the target temperature. But yes, technically, it’s a loss of efficiency. ---
**Author:** ![YamatoTwinkie](https://avatars.discourse-cdn.com/v4/letter/y/cc9497/32.png) [@YamatoTwinkie](https://boards.straightdope.com/u/YamatoTwinkie)\ **Post date:** [February 27, 2020, 8:06pm UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/35 "2020-02-27T20:06:23Z")
> [@CookingWithGas](#): > > I agree that’s true, although the greatest heat loss rate occurs when the pot reaches the maximum temperature. I don’t have the numbers but the difference in heat loss during heating is probably negligible compared to the heat added to bring it to the target temperature. But yes, technically, it’s a loss of efficiency. In this case, once the pot reaches maximum temperature, it’s used for cocoa immediately. While heat transfer _rate_ is greatest at max temperature - the pot (ideally) spends zero time at max temp, so zero energy is lost during this period. Unless OPs standard process for heating water is “Put kettle on, then go to the store and come back 15 minutes later” -the sooner max temperature is reached, the less heat is lost overall. ---
**Author:** ![Banksiaman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/banksiaman/32/3334_2.png) [@Banksiaman](https://boards.straightdope.com/u/Banksiaman)\ **Post date:** [February 28, 2020, 9:15am UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/36 "2020-02-28T09:15:54Z")
I’ve just been away for a few days. The motel I stayed in has an electric kettle, tea bags and coffee sachets so I could make a cup of tea [or shite coffee] any time I felt like it. What do you have in American motels to fulfil this essential function? ---
**Author:** ![EdelweissPirate](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@EdelweissPirate](https://boards.straightdope.com/u/EdelweissPirate)\ **Post date:** [February 28, 2020, 9:51am UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/37 "2020-02-28T09:51:31Z")
Drip coffee makers. You can get hot water for tea just by leaving out the coffee and filter. It’s essentially an electric kettle with a fancy dripping mechanism. I mean, they both make the kind of coffee the French call _eau de chausettes._ ---
**Author:** ![psychonaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/psychonaut/32/4655_2.png) [@psychonaut](https://boards.straightdope.com/u/psychonaut)\ **Post date:** [February 28, 2020, 10:54am UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/38 "2020-02-28T10:54:22Z")
> [@EdelweissPirate](#): > > Drip coffee makers. You can get hot water for tea just by leaving out the coffee and filter. It’s essentially an electric kettle with a fancy dripping mechanism. I mean, they both make the kind of coffee the French call _eau de chausettes._ This isn’t ideal—coffee is normally brewed at 90 to 95 °C, whereas for tea you really want boiling water. ---
**Author:** ![EdelweissPirate](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@EdelweissPirate](https://boards.straightdope.com/u/EdelweissPirate)\ **Post date:** [February 28, 2020, 11:03am UTC](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406/39 "2020-02-28T11:03:53Z")
Which part of my post asserted that crappy motel coffee makers are ideal for _any_ use? 🙂 [Previous page](https://boards.straightdope.com/t/microwave-vs-electric-kettle/848406.md?page=1)