Tolerable Tea Brewing Temperature

[Ivan]

I'd like to find out what temperatures people can tolerate their tea brewing at.

If you research it, the technical answer is 100C, but a lot of people make it at lower temperature (if you put the milk in first, you won't get anywhere near boiling point). From my brief experiments, I have found that several tea drinkers cannot tell the difference (or rather 'do not notice the difference') between tea brewed at 100C and tea brewed at temperatures down to 80C and slightly lower. For example:

I made a cup of solar-powered tea at 78C, and the drinker could not tell the difference (instant tea bag, white, no sugar). I wonder if certain types of tea are more likely to require higher temperatures.

Today is cloudy, and we have had no sun. By 3.30pm, my Navitron solar-kettle had reached 72C - which means that if you can make tea at 80C, it is possible to have a hot cup of tea even on a cloudy, overcast summer day.

Anyone care to do some experiments and report back?



Ivan

[Amaterasu]

Ivan
I think you need to make a distinction between brewing tea and boiling water.
Most people will boil the kettle (to boiling point -  ) and then make their drink from the results of that.

Brewing tea normally involves adding the hot water to the tea (or vice versa).

If you use the old fashioned method then tradition dictates that you "warm the pot" by swilling it with hot water first
Then add your tea (leaves) and hot water and allow to "brew" (stand) for a while.
Once brewed you decant into a cup and add milk to taste.

Nowadays most people use bags and the method has become blurred.
Personally I put the milk in the bottom of the cup - chuck in a bag, followed by the water.
After a number of stirs I remove the bag and squeeze with my thumb - this later process extracts the strongest fluid.

As for temperatures I suspect that as soon as you add any cold fluid the drop will be quite large. Its all to do with latent heat and absorbtion.

I'll carry out some experiments with kettle boiled water and cooling with milk tonight.

Are you intending to have the whole drink inside the tube from scratch. IE add milk tea and water in correct ratios and heat in the sun.
That way you shouldnt need to get the water temp above what would be palatable.

I'm not sure what the effect would be on the flavour !

[mike85]

Amaterasu,

I think what Ivan is trying to distinguish (as a non tea drinker) is if the temperature of the water added to the tea makes a difference to the final taste.
The idea is that if it doesn't make much difference we could simply heat the water to 70-80 degrees (shouldn't take long on a sunny day) before adding it to the tea bag and milk. Heating the water to 100 degrees would require sealing the end of the tube and make the process a lot more time consuming.

Mike

[Mike N.]

I was taught (at an age before I learned to question such things) that thge 100 degrees was essential to cause cell walls to rupture as the water content expanded and this then let the flavour out, It may be that this is not true. I am all in favour of this theory being disproved by research

Mike

[kristen]

http://en.wikipedia.org/wiki/Tea

"Typically, the best temperature for brewing tea can be determined by its type. Teas that have little or no oxidation period, such as a green or white tea, are best brewed at lower temperatures around 80°C, while teas with longer oxidation periods should be brewed at higher temperatures around 100°C."

So change your Brand and you'll be fine!

Kristen

[Mike N.]

Done some research...

Googling "how to make  tea" gives the usual 61m results. I've yet to find one that doesn't stress that the water must be boiling, not just boiled. Other interesting points include the perennial question as to whether you add the milk before or after (assuming that you are pouring the tea made with boiling water from a pot of course). It appears to be a social rather than a scientific thing, but I haven't read all 61m yet (and may well not  )

Mike
(Earl Grey, milk, no sugar  and definitely none of that poncey lemon)

[martin]

I was under the impression that it was a "manners" thing - Nancy Mitford in "U and non-U" refers to people who are "mif" - "milk- in-first!"  - and seen by the snobbish as being very downmarket for doing so!
The origin of that was supposed to be that the common 'oi polloi could only afford cheapo earthenware cups which would crack or craze if subjected to tea straight out of the pot, so the oiks put their milk in first to preserve their pottery!

[Ivan]

well I am handicapped in this debate, as I don't drink tea. But I am starting to think it is more about folklore or perfectionism than reality - instant tea, which most people drink, is quite different from 'real tea' - and I think a lot of the tradition comes from real tea. I, too, found everything on the internet seemed to point towards boiling water directly onto tea bag.....but I think this is because everyone is repeating what they have been told or read elsewhere.

What we need is some practical research - so far, I have made a few cups of tea at between 78 and 100C - and all have been perceived as being identical to a 'proper' cup of instant tea (as opposed to 'tastes ok but not quite right'). Having done research for 8 years of my life, I have discovered that it is quite possible to overturn some of the fundamental rules through experimentation.

I think it is probably desirable to heat only water in the tube, as it keeps hygiene and cleaning issues manageable  (can't easily put them in the dishwasher!!)


Ivan