My kettle has separate setting for tea (boiling) and coffee (not quite boiling).
What's the science behind this ?

Ah yes, we had something similar once.... before....???
Anyway, yes the science is quite simple as I recall.
To produce a full infusion of Tea requires water to be at a higher temperature than for Coffee grounds.... I'm not sure if this applies to freeze dried Coffee granules but I suspect it does.
Anyway it's all down to the way in which the respective soluble components are presented. Tea is simply the dried leaf broken into small pieces which presents a small cellular cross section (relative to total volume) whilst Coffee is ground roasted bean which presents a much greater surface area.
Thus it requires less heat to release the soluble components from Coffee than it does from Tea and so your kettle has conveniently had these values pre-set, which is most convenient I must say.

Actually MPL, i beleive that coffee becomes bitter if made with boiling water, and so just below is preferable....

You know what I was just coming back in here correct myself Nails.
Yes you are correct, the higher temperature has a detrimental effect on the taste, I don't recall why exactly, but it does indeed tend to taste bitter if made with boiling water. I always boil the kettle and let it cool for a minute but having a pre-set temperature would be much more efficient.

Aha, so that's why coffee mysteriously (well not any more) tastes better if you mix in the milk first...

It's annoying isn't it Colm, you get to a 'certain' point in life when you think you have most of the basics covered and then someone throws a wide ball at you like that.
I mean coffee, we've been drinking it for years and yet my best instruction on it's preparation comes from Michaels Caine's portrayal of Harry Palmer in the Ipcress File.
How sad is that.

I may as well be sitting in my mums attic. Lol.

You know something..

quote:

Aha, so that's why coffee mysteriously (well not any more) tastes better if you mix in the milk first...

I've never tried that.

To the kitchen!

I thought it was about time I did a practical experiment.
This will not stand up to scientific scrutiny, but this morning I made two cups of coffee, one on each setting. The only difference I could detect was that the one made on the T setting was hotter than the one made on the C setting. The taste was equally average.
The coffee was instant granules, and I like it without milk (initially through laziness but I've got used to it).
Tomorrow is "posh coffee" day, so I will repeat the experiment with ground coffee beans.

Using water at too high a temperature definitely imparts a bitter taste to coffee, perhaps you simply didn't notice a difference. Maybe the coffee you made was to weak a concentration.

I only have one cup of coffee a day but I make it using Douwe Egberts medium roast in a cafetiere, it's nothing special but less faff than grinding your own first thing in the morning.
I reckon you always get the best cup from the first serving after the vacuum seal is broken, from then on it's downhill and even when kept in an airtight jar in the fridge after a week it is just not as good.
However I have noticed that using boiling water can make even the freshest grounds taste distinctly bitter and yet water that has gone off the boil will certainly make it taste better.
One tip for 'rescuing' past its best ground coffee, put a teaspoon of raw coco powder into the mix, et voilà, you have Mocha.

I have a coffee grinder MPL and I must say nothing beats actual freshly ground coffee as opposed to faux freshly ground coffee like those vacuum sealed bags. I'm not bothered to actually grind coffee every day though. I do suspect that day old ground coffee will be just as good as the day it was ground so I suppose I could grind some every other day.

hmm, I fear my "posh coffee" will not be up to the mark, being pre-ground in one of those vacuum sealed bags My wife keeps it in the freezer - does that make any difference ?

I would think that constant cycles of freezing and thawing might do some damage but don't quote me...

You should still notice a bitter taste if using pre-ground coffee(aka "freshly" ground coffee) from the bags. Or you could go all out and get a grinder, it's not that much work, honest.

I have to admit it's laziness on my part and indifference from Mrs. MPL who drinks neither coffee nor tea, that put me of grinding my own Ush. I never seemed to be able to do it without making an infernal mess of the kitchen bench and cause brown stains on just about everything, but you are right stored home ground will keep just as well, if not even better than the vacuum packed stuff and Lou, I'm not sure if freezing helps, to be honest it had never even occurred to me before but I suppose it could be beneficial, just so long as you let it return to room temperature before dowsing it with scalding water.

As for it being 'posh' well some time ago I realised that drinking an almost endless line of instant cuppas every day was not doing me any good so I decided that if I was only going to have one cup a day, then it would have to be half decent at least. Plus I'm not entirely convinced that 'instant' keeps any better than ground.

Does anyone recall Douglas Adams guide to making a good cup of tea? I think it was mainly aimed at Americans, and he thought that if you followed his instructions you would sincerely appreciate what a fine beverage it is.

Where I work, we get cups of hot-brown. Don't know what it is but it's hot and it's brown.