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Author Topic: Why does tea taste different when it's cold?  (Read 10950 times)

Offline Olga

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Why does tea taste different when it's cold?
« on: 19/10/2008 13:16:05 »
Olga asked the Naked Scientists:

Why do things taste different (better/worse) when hot/cold?

Specifically tea. It's always hard to finish a cup of tea that has gone cold before you have had chance to get back to it in time.

What do you think?


 

Offline chris

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Why does tea taste different when it's cold?
« Reply #1 on: 20/10/2008 08:02:29 »
I suspect that this is because several aspects change with temperature:

1) The viscosity - warmer liquids (including water but especially oils) are less viscious at higher temperatures and this will affect the sensation of the liquid in the mouth.

2) Receptor interactions - we sense chemicals in food and drink using chemical docking stations (receptors) which are distributed around the tongue and mouth. Some molecules interact strongly with their respective receptors (even at cold temperatures), always giving a good signal. Other substances interact less willingly but do so more keenly at higher temperatures - this is because the particles have more energy and are therefore are moving faster; this produces more collisions with the receptor and at higher speed, favouring successful interactions.

3) Density effects - When a cup of milky tea goes cold the convective effects of the hot liquid cease. These normally keep the consituents of the drink well mixed by "stirring" the liquid in the cup. But when the tea goes cold this thermal stirring stops and so the consituents begin to separate by density. The fat from the milk you added rises to the top, the heavier tea particles sink to the bottom. As a result the composition of the average sip you take is different, so not surprisingly so is the taste.

Chris
 

blakestyger

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Why does tea taste different when it's cold?
« Reply #2 on: 20/10/2008 12:03:48 »
This isn't quite the same but while we're on taste, how is it that macaws are fed dried chillies as part of their diet? They don't seem to suffer the afterburn effect that we do next day after a particularly hot chili dish.
 

Offline Don_1

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Why does tea taste different when it's cold?
« Reply #3 on: 20/10/2008 16:56:51 »
There are some people who actually like cold tea! And even a few who prefer tea cold.

I think it's a matter of personal taste.
 

Offline Bored chemist

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Why does tea taste different when it's cold?
« Reply #4 on: 20/10/2008 20:19:12 »
A lot of what is called taste is actually smell. So the temperature might well make a difference. At a different temperature the mixture of volatiles will be different so they will smell different.
 

Offline dentstudent

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Why does tea taste different when it's cold?
« Reply #5 on: 21/10/2008 09:31:38 »
There are some people who actually like cold tea! And even a few who prefer tea cold.

I think it's a matter of personal taste.

I take it that you've not had proper iced tea? It's hugely refreshing in summer - lots of ice and lemon.....There is also iced coffee which is also very nice - with a dash of rum and some cream over crushed ice, it's also a great drink!
 

Offline chris

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Why does tea taste different when it's cold?
« Reply #6 on: 21/10/2008 17:27:07 »
Thanks BC, that's a very important point that I missed.

And BT, birds lack the receptor (known as TRP-V1) that is required to detect (and experience the burn) of the chemical, called capsaicin, that gives chillis their kick. As a result birds can eat curry with impunity.

But don't be tempted to over-feed them curry - a friend of mine did that to a chicken once and it slipped into a "korma".

Chris
 

Offline Olga

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Why does tea taste different when it's cold?
« Reply #7 on: 22/10/2008 00:36:09 »
I have had lots of lovely iced tea but it's not the same as having made a cup of tea, intended to be consumed whilst hot, and then ended up drinking it a little later than planned. My lab work is the usual culprit for distracting me and causing me forget about it.  Reheated tea never tastes the same either, even when made without milk which is how I normally have it. I don't drink coffee but am led to believe the same is true. Judging by the colour of my cup all the tasty stuff comes out of the tea as it cools and doesnít go back in to solution on reheating.
Thanks for all your answers. Iíll be sure to keep a tract of time post-brew from now on.
 :D
 

Offline Don_1

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Why does tea taste different when it's cold?
« Reply #8 on: 22/10/2008 15:23:20 »
There are some people who actually like cold tea! And even a few who prefer tea cold.

I think it's a matter of personal taste.

I take it that you've not had proper iced tea? It's hugely refreshing in summer - lots of ice and lemon.....There is also iced coffee which is also very nice - with a dash of rum and some cream over crushed ice, it's also a great drink!

Iced tea I do like, but not cold tea with milk in.

 

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Why does tea taste different when it's cold?
« Reply #8 on: 22/10/2008 15:23:20 »

 

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