How is Tea Decaffeinated?

How is Tea Decaffeinated?

Blog Key Takeaways:

1. **Challenges of Decaffeination**: All true teas from the Camellia sinensis plant contain caffeine, and removing caffeine without compromising the tea's quality is challenging. Most methods either damage the leaves, leave an unpleasant aftertaste, remove antioxidants, or are difficult and expensive to implement.

2. **Water Processing Method**: Water processing is a simple, home-based method where you steep tea for about 30 seconds, discard the liquid, and re-steep the leaves. However, research indicates this method only reduces caffeine by about 9%, making it ineffective.

3. **Ethyl Acetate Method**: The most common commercial method uses ethyl acetate, a solvent that removes caffeine but also strips most antioxidants and leaves a chemical aftertaste. This method is sometimes marketed as "naturally decaffeinated," although it involves the use of a solvent found in nail polish remover.

4. **CO2 Method**: The best decaffeination method involves using supercritical CO2, which is effective and retains about 92% of the tea's antioxidants. This method is expensive and complex, involving high pressure and heat to create a supercritical fluid that selectively binds to caffeine molecules.

5. **Availability and Alternatives**: Due to the cost and difficulty of decaffeination, decaf versions are usually limited to common tea varieties. For a wider range of caffeine-free options, herbal teas and rooibos are recommended, as they naturally do not contain caffeine.

All true teas, that is to say, teas which are made with the leaves of camellia sinensis, contain caffeine.  Removing the caffeine from these leaves is quite the challenge, and there is no perfect way to do it.  All methods either damage the leaves, leaving an unpleasant aftertaste, and almost no antioxidants, are very difficult and expensive to use, or don’t work.  There are four common methods of decaffeination for tea: using ethyl acetate, using methylene chloride, using carbon dioxide, or using water processing.

water process decaffeinated teaWater processing is the easiest method.  Tea cannot be stored after it is water processed, which makes it impractical for commercial purposes.  However, you can use water processing to decaffeinate your tea yourself.  This is a very simple method.  You make a cup of tea, as you usually would, but after about 30 seconds, you pour it out, and then re-steep it.  The idea is that caffeine steeps faster than the flavor, so while you do lose a great deal of flavor, you lose more caffeine.  The problem with this method is that it likely doesn’t actually work.  The scientific research done by Hicks et all concluded that a 30 second steep of western style tea bags resulted in a 9% reduction of caffeine.* This seems hardly worth the time and effort.


 >>>>>> Check out our Decaffeinated Teas <<<<<<<

Ethyl acetate is the most commonly used process of decaffeination.  Ethyl acetate is a solvent which literally strips the caffeine from the leaves.  It should be noted that both ethyl acetate and methylene chloride are commonly used as the active ingredient in nail polish remover.  This means that both of these methods leave the slight, unpleasant aftertaste of caustic chemicals.  These methods also strip the majority of the antioxidants from the leaves, as  well.   According to this website, they only leave behind about 18%.

 >>> Read the blog post discussing Caffeine Free V Decaf <<<<

The ethyl acetate method of decaffeinating tea is frequently advertised as “naturally decaffeinated,” because it sounds better than “decaffeinated with nail polish remover.”  This is technically a true claim, given that, like arsenic, ethyl acetone is a naturally occurring compound.  If your tea claims to be “naturally decaffeinated,” this is how it was done.

 >>>>>> Check out our Decaffeinated Teas <<<<<<<

decaffeinated tea supercritical fluid CO2 method


The best method for decaffeinating teas is the CO2 method.  This is the only method which we use at Good Life Tea.  The CO2 method is challenging because it is very expensive, but it works remarkably well.  It leaves behind about 92% of the tea’s antioxidants, rather than the 18% of the ethyl acetate method.  The way in which it is done is also really, really cool.  The tea and the CO2 are put together in a closed container, which is then put under enormous pressure.  This pressure is usually about 300 bars.  For reference, a car tire is usually under about 3 bars of pressure.  Then, heat is applied.  Under this much pressure, the CO2 become what is called a supercritical fluid.  This means that it should, technically be a gas, however, it can’t, because there is just too much pressure.  Supercritical fluids also turn up in other places, like when steam escapes the earth’s crust at the bottom of the ocean, and on the surface of Venus.  The CO2 the begins to bind with the smallest molecules in the tea leaves, which is to say, the caffeine.  This method is the best at removing just the caffeine, and very little of the flavor or antioxidants.  

 >>> Read the blog post discussing Caffeine Free V Decaf <<<<

Decaf versions are usually only made of the most common varieties of teas, because decaffeinating them is a costly and difficult process.  If you’re looking to explore more decaf teas, I highly recommend taking a look at our herbal and rooibos teas, which are naturally without caffeine.

 >>>>>> Check out our Decaffeinated Teas <<<<<<<

* Food Research International Vol 29, Nos 3-4, pp. 325-330.

Check out some of our decaffeinated teas below!


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1 comment
  • Well written

    Krystal on

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