26

Imagine you're making someone a tea, but for whatever reason they have to leave soon. How can I cool the tea so that they don't have to choose between leaving it unfinished or burning their mouth? Ideally the method should not only be fast, but also let me reliably reach about the same temperature every time.

I've thought of the following:

Add additional milk - cools tea, but affects taste.

Heat the water less - won't make tea as hot, but might affect how well the tea infuses.

Add cool water to boiled water - would cool down a fully-infused tea, but hard to control resulting temperature.

Put it in the fridge for 30 seconds or so - would cool tea, but seems like a bad idea.

  • 7
    Con: Inexact science on the contrary, thermodynamics is a very exact and well understood science. In a nutshell, the final temperature is the weighted mean of the temperatures of both liquids (assuming nothing else influences the temperature, which on very short period is close enough). e.g. to cool 250ml of 70* tea to 60*, simply add 50ml of 10* water to it. – njzk2 Dec 17 '15 at 1:14
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    @njzk2 If you keep chilled water in the fridge it'll work, but otherwise the water temperature won't be very controlled, so it's hard to make it reliable. – Cascabel Dec 17 '15 at 4:20
  • I doubt putting a hot mug of tea in the fridge would cool it all that quickly, especially if the mug was prewarmed and ceramic. But someone with a thermometer and some freshly brewed tea can probably take measurements of all these methods fairly easily and report back. – Batman Dec 17 '15 at 5:08
  • Some types of tea (green for example) are supposed to be brewed with less-than-boiling water anyway, so you could use correctly tempered water in the first place. – rackandboneman Dec 17 '15 at 13:01
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    There's an ISO standard for brewing, FWIW. en.wikipedia.org/wiki/ISO_3103 – Pranab Dec 21 '15 at 3:51

14 Answers 14

47

What is wrong with a regular ice cube? As you state that the tea is not yet ready, you just use slightly less water and then add the ice cube, which has a fixed temperature.

I use this for large scale ice tea production. As I use 1:1 hot water : ice cubes I simply brew a double strong tea.

  • 2
    I think this is a perfectly reasonable suggestion. This is exactly what I do when I make tea for my kids. – Digital Trauma Dec 17 '15 at 0:58
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    To improve this method, I suggest stirring the ice cube in so it melts a bit faster, then fishing it out with your spoon once the tea is at the desired temperature to avoid further cooling. – Zibbobz Dec 18 '15 at 14:24
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    @LarsFriedrich If I understand right, AleOtero93 is just suggesting using frozen tea cubes instead of frozen water cubes, so that adding them doesn't dilute the flavor of the hot tea you just made. (Tea does have flavor.) That is, it's an alternative to brewing extra strength tea before adding ice cubes. Would be a pain if you don't drink the same kind of tea all the time, but otherwise seems reasonable enough. – Cascabel Dec 18 '15 at 20:46
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    @Jefromi It is an alternative without any advantages, only disadvantages. Filling the cup with a little less water is simple and efficient and you do not dilute the tea as in 'reduce the taste' that way. I don't see how providing an inferior alternative would improve my answer. Not to mention that tea ice cubes already exist as answer. – John Hammond Dec 18 '15 at 22:26
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    You're adding water, so you do dilute it a bit, it's just not enough to matter, right? I wasn't telling you had to add it, just explaining, since that comment was a little hard to read you seemed to be focusing on "is tea a flavor" rather than the actual content of the comment. – Cascabel Dec 18 '15 at 22:44
37

One solution would be to use Whiskey Stones. These are essentially stone (or metal) cubes that you normally use for whiskey to chill it without diluting it. This will also work for your tea

whisky stones enter image description here

However, if this is a problem you run into regularly, you can freeze an ice tray with tea to make tea ice cubes and use that to cool down your tea. The main downside is, you would need to use the ice cubes on the same type of tea or it will affect the taste of the tea.

  • 1
    Alternative: put regular ice cubes in a plastic bag and submerge it in the tea (or pour the tea over the back). – Raphael Dec 17 '15 at 19:43
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    @JoeBlow Surface area is only part of the equation; heat dissipation and amount of material are relevant, too. A thin metal cup may very well have less material than a couple of cubes and thus may take less heat. A case can be made against stones when you want quick cooling (not what they are made for, stone usually dissipate heat slowly); metal cubes should not have any problem with that. – Raphael Dec 17 '15 at 19:45
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    The specific heat of the material doesn't really matter. The specific heat of ice is 2.03 Joules per gram per degree Kelvin. It's the enthalpy of fusion of water that is the big deal: 334 Joules to melt 1 gram of ice. Dave Arnold goes into detail about this, and he declares that the cardinal rule of cocktails is there is no chilling without dilution, and there is no dilution without chilling. Here's post on the cooking issues blog that goes into a lot of detail on it: cookingissues.com/index.html%3Fp=4585.html – Rosa Richter Dec 18 '15 at 2:11
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    @cantido - This is a valid point, but it's a bigger deal regarding tea than with cocktails, because the temperature differential between room temperature (or ice or freezer or whatever) and the tea is much greater, making the specific heat more relevant. For example, the specific heat of water is about 4.2 J/g-K. For a cocktail, the water might only rise 5-10C after melting until the drink reaches equilibrium, making specific heat only about 10% of the total cooling. But for hot tea, the raising the water temp from freezing to tea temp is likely more than 40% of the total cooling effect. – Athanasius Dec 18 '15 at 17:35
  • @Athanasius good point! – Rosa Richter Dec 18 '15 at 19:25
33

Possibly even easier than using ice or fridges or anything... pour it repeatedly from one container to another. Constant exposure to the air will rapidly cool the drink, you can get it to drinking temperature in less than a minute.

(Just make sure you pour accurately, or use larger containers. Spilling hot tea is no fun.)

Here's an example of a street vendor, who likes to be a show-off with this kind of thing. You can see him cool tea to drinking temperature in 10 seconds.

https://www.youtube.com/watch?v=-surEvJXj34

  • 2
    This is kinda obvious in India, it gives a nice froth to chai, cooling it is the secondary purpose. – Jesvin Jose Dec 17 '15 at 15:38
  • You can put the containers in the fridge beforehand -- if they are metal. – Raphael Dec 17 '15 at 19:40
  • @Raphael No point, if they're metal. Metals have such a low specific heat capacity that it takes almost no energy for the cup to come to the temperature of its contents. Indeed, drinks actually cool slightly more slowly in thin metal cups than, say, ceramic cups: the reason is that bringing a metal cup up to the temperature of the drink takes almost no energy from it and then the only cooling is by convection; a ceramic cup removes much more energy from the drink as the cup warms. – David Richerby Dec 20 '15 at 11:52
  • It is also very helpful to let the tea sit in these two different containers. Two mugs have twice the air contact as one. I use this technique often. – Rick Dec 24 '15 at 18:08
19

I do this everyday before I leave for work. I can't have really hot tea. So once my tea is ready:

  1. I put it in a tea pan (a deep pan used to make tea). You can substitute with any other clean deep pan.
  2. Add cold water to the kitchen sink
  3. Stand the tea pan in the kitchen sink for 2-4 minutes

And I have the perfect temperature for my tea that suits me :)

enter image description here

You can always stand it in cold water for more or less time to suit you. And it does not affect the taste of the tea. I have tried to put the tea in the fridge before but it hasn't worked for me.

  • I've never heard of a tea pan... what is that? – Catija Dec 16 '15 at 20:43
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    @Catija: I've edited the answer for more detail. But essentially, its just a pan that is used to make tea by boiling the water and tea together. Nothing special, just a deep pan :) – Divi Dec 16 '15 at 20:50
  • Oh... so that's a completely different method for making tea than I've ever used. I would never boil tea leaves. I boil the water, let it cool slightly and add the tea afterwards, once it's in the cup or in a teapot... then let it sit for a couple of minutes to brew. – Catija Dec 16 '15 at 20:52
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    @Catija: I think it's more an Indian way of making tea, to boil water, tea leaves, sugar and milk together – Divi Dec 16 '15 at 20:55
15

Pour the tea back and forth between two cups until the desired temperature.

Adjusting the height of pouring is fun to play with to get faster results but try it over a kitchen sink.

  • 1
    +1 - this is by far the easiest and most effective answer. – Bob Tway Dec 17 '15 at 17:20
  • Exactly as Matt says. The amount of surface area (with all the air, when in a "column" is enormous). – Fattie Dec 17 '15 at 18:11
  • Not very efficient, sloshing water will also cause it to warm (that's why it has to be much below 32° for a river to freeze) – bjb568 Dec 19 '15 at 17:17
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    @bjb568 The warming effects of friction within the hot tea are pretty negligible compared to the cooling effects of being poured through and mixed with room-temperature air. Specifically, if you pour the tea back and forth for a long time, your tea will reach a temperature slightly above room temp -- but that's massively cooler than the temperature the tea started at! – David Richerby Dec 20 '15 at 11:55
9

If you'd love to bring a gadget into play:

enter image description here

Many parents use a "Cool Twister" to quickly bring the water for baby bottles from boiling to a choosen temperature in less than 90 seconds. You could also run your tea through it and cool it down - or parts of it.

The manufacturer suggests the use for tea and coffee on his website as well:

Can the Cool Twister also cool down coffee or tea? Basically yes. The temperature can be chosen individually between approx. 40 and 80° C. [...]

7

Boring but effective: brew, pour and sugar/cream as usual; when teacup/mug is hot to the touch, transfer to fresh cup.

7

I put a silver spoon in the tea. It makes the spoon extremely hot very quickly, but the silver spoon will take the heat. Careful when removing the spoon as it will be hotter than you imagine!

  • 1
    This is my preferred method too. I don't have silver, so I just stick 3-4 stainless steel tablespoons in the tea. Their conduction is not as good as that of silver, but the greater thermal mass and greater area makes up for it. – rumtscho Dec 17 '15 at 17:31
  • The spoon will attain the same temperature as the tea, now slightly below the starting temperature; it can't cool it down more. If you want to really cool it down, you need to remove the spoon, wait for it to cool down (happens quite quickly) and then put it back in. – Raphael Dec 17 '15 at 19:41
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    @Raphael actually, the spoon's "stem" conducts heat to the air. It's not perfect, but with sufficient spoon-to-tea mass, it delivers results reasonably quickly. – rumtscho Dec 17 '15 at 20:12
  • I was thinking of a big cup and a table spoon, so there would be not much spoon above the surface. If the size ratio is more favorable, it may work well, agreed. – Raphael Dec 17 '15 at 20:52
6

make a concentrated infusion (same amount of tea less (boiling) water). When finished fill up with cold water.

  • This is exactly how I do it every morning. Make strong tea, put half an inch of cold water in the bottom of the mug, poor tea into mug. Done. This is also fantastically simple. – abligh Dec 17 '15 at 22:55
  • Do you need to adjust steep times to do this method? – Brad Dec 18 '15 at 23:30
  • I don't, I just use the same amount of tee with only half as much of water and top up with cold water after steeping – D.F.F Dec 19 '15 at 20:43
3

The system I use at my office desk is this: I have a small aluminum soda can (7.5 oz size) that I keep about an inch and a half of water in. I leave about 1.75" of empty space from the top of my mug. Once the tea is made and infused, I simply float the can in the tea for a bit. This pulls out just enough heat to make the tea pleasantly hot with no mouth burning.

(Note: Don't forget to clean the can and change the water so the water doesn't get nasty.)

3

A saucer was invented for that purpose (to accompany cups with a handle). Pour hot tea into saucer using the handle provided and slowly drink off from a point on its edge while raising the diametrically opposite point.

2

Stirring with any metal spoon will rapidly cool the tea, as the metal will absorb the heat. Silver, as suggested, is a good conductor, but any metal will do.

According to Physics.SE (and graciously cited by XKCD What-If), dipping the spoon in and out is slightly faster, though not by a highly significant value, and stirring or simply doing nothing will still get similar results.

Note that while you could use the results of that first link to time your own tea-cooling, I would recommend timing it yourself in your own environment, since the temperature and air pressure is likely to be different for you wherever you drink tea.

  • 3
    To be fair though, the Physics post was restricting itself to only using a spoon to cool the coffee. The current question is asking for the general case when several (more viable) alternatives are available. – Kyle Kanos Dec 19 '15 at 17:28
1

Shake it up (in a cocktail shaker?) with ice cubes then pour it out again through a strainer. This is how I make iced tea in summer. Obviously you shake it a bit longer for iced tea!

1

If you like to sugar your tea, you can replace the sugar by honey. It's better to me (but it also depends on your taste ^^).

Enjoy your tea !

  • 2
    How much of a difference would a teaspoon of honey vs. a teaspoon of sugar make? – Stephie Dec 18 '15 at 15:12
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    You can put a big spoon of honey instead a little spoon of sugar. It won't cool your tea instantly, but a little bit faster. When a hot fluid encounter a cold fluid, there is a heat transfert. The cold fluid will "absorb" the heat, according to heat transfert principle. Like your honey is colder than your tea, it will decrease the heat. – Tofuw Dec 18 '15 at 15:26

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