All About Decaffeinated Tea - part 1 of 3



Giving up caffeine?

I've heard it a thousand times.

I can't sleep at night if I have a cup of tea too late... I'm trying to cut down on caffeine... I've got this new health regime...

Yes, these are all great reasons for drinking decaffeinated tea. And yes, All About Tea does stock some great decafs. But before you rush to the website and buy them, let's have a look at the whole caffeine issue and try and demystify it a bit.

What is caffeine?

Caffeine occurs naturally in a small number of plants, and is given a different name in each case- though the substance is the same. In coffee, it is caffeine, from the German kaffein. In tea it is theine, in yerba mate it is mateine and in guarana, guaranine. It also occurs famously in the kola nut, much chewed in West Africa, which is used in the manufacture of cola drinks. The kola nut is related to cocoa, which of course also contains caffeine.

So what is the point of caffeine, other than helping feckless undergraduates get their essays in on time? The answer is that it is a natural pesticide, and protects young plants and berries, for example the coffee cherry that coffee beans come from. So caffeine levels are higher in young leaves.

Good things about caffeine

Caffeine is great at the right time and in moderation.  It acts quickly (within an hour), and the effects wear off quickly (within 3 or 4 hours).  It increases physical endurance (studies have shown this in runners and cyclists).  It also increases capacity for mental work - as many a late night worker can testify.  And yes, it keeps you awake.  Which is great sometimes.  Another effect is reduction in weight gain, perhaps due to stimulation of the nervous system and inceased metabolic rate.

Bad things about caffeine

You get used to it.  Tolerance develops, which means that it has less effect as you get used to it.  It also means that the effect of NOT having it is greater - ie, you start to need it.  This explains why many people can drink coffee and still sleep - it takes 7 days to become sufficiently tolerant not to be kept awake by your normal consumption.

You can have withdrawal effects if you stop drinking caffeine - headaches, sleepiness, etc.  In overdose, it can cause irritability, anxiety and headaches.

Decaffeination

OK - so you want to cut down on caffeine.  So you decide to drink decaffeinated tea or coffee.  How do they get the caffeine out in the first place?

Caffeine is soluble.  It dissolves in water, for example - which is why it ends up in your body when you drink your morning cuppa.  So to remove the caffeine is simply a matter of dissolving it whilst leaving everything else, including the flavour, in place - not as easy as it sounds.  There are 3 highly selective caffeine solvents used in decaffeination.

CARBON DIOXIDE

CO2 is very safe and an excellent solvent of caffeine.   It also becomes a liquid at high pressures.  Even better, it can be persuaded into a "supercritical" state where it is both a gas and a liquid.  This means that it can get right into the tea leaves (like a gas), and dissolve the caffeine (like a liquid).

ETHYL ACETATE/METHYL CHLORIDE

These organic compounds are excellent caffeine solvents.  They are widely used in the tea and coffee trades.  They are not very nice chemicals, though the amount that remains is tiny and safe, so do not worry about those supermarket teabags.

WATER

Water is used to decaffeinate coffee - the so called Swiss Water method.  The beans are soaked in water, which dissolves the caffeine and quite a lot of the flavour-containing compounds.  Then it is filtered through charcoal, which soaks up the caffeine, and then added back to the coffee beans and allowed to evaporate, hopefully putting all the flavour back in the beans.

Does Decaf taste the same?

No, I'm afraid it doesn't.  Decaffeination is getting better and better, but these teas are still too often flat and taste of cardboard.  AAT has some decaf teas which we think are pretty good - but it'll never be the same as the real thing.  The best we have, in my opinion, is the tea we use in our Decaffeinated English Breakfast Teabags.  So that's the one to try first.  But check part 3 on Friday for some more ideas which may bring you back to real tea - without the sleepless night!