Decaffeinated Tea

Did you know tea can be decaffeinated in 4 ways?
Read below to learn how and how also you could “decaffeinate” at home?

Firstly Samantha from the Art of Tea spoke on ABC radio on 23rd August 2023 aboout the decaffeination process.
Listen Here for the ABC Hobart Radio interview with Joel Rheinberger

Essentially there are 4 methods, the first 2 being similar and could be named “the chemincal/solvent method”

The two “chemical” processes
Tea leaves can be immersed in a solvent of Methylene chloride or Ethyl Acetate. Immersed in either solvent the tea leaves leach out the naturally formed caffeine molecules, leaving the leaf largely “decaffeinated”.

1.
The Methylene Chloride process is least favourable methos and in many cases the tea leaves having undergone this process are banned from being imported to many countries.

2.
The Ethyl Acetate process, whilst in itself is a natural component in miniscule concentration in a tea leaf, where upon being bathed in a higher concntration as a solvent for the purpose of leaching caffeine molecule, may also be considered as a “chemical extraction ” decaffeination process.

3. Carbon Dioxide (CO2) decaffeination

The third method to decaffeinate tea is the commercially most popular. By pressuring and heating the natural CO2 gas and then exposing the tea leaves to the pressurised CO2 the smaller caffeine molecules release from the leaf. Leaving, in part, the majority of larger molecules of flavour/ flavanoids.

4. Water Method (a) commercial
The fourth decaffeination proces involves at a commercial scale exposing the tea leaves to hot (close to boiling) water for a period of time that results in the caffeine molecules leaching out. The water is then circulated through a carbon filter to remove caffeine molecules then the solution is reintroduced to the tea leaf to potentially allow the tea leaves to reabsorb any flavours and oils.

The above methods remove the majority of the caffeine but there is no certification to prove that all caffeine has been removed. Under certain criteria, eg 2mg caffeine, the term “caffeine free” or “decaffeinated can be used. Country by country labelling specificatons may vary. But Decaf tea and coffee are NOT 100% caffeine Free.

Water Method (b) at home

If you have ever wondered if you can reduce caffeine or “decaf your own tea” .. then yes, and you can do this method at home. There is a simple method.
Though no (post brew) testing is ostensibly possible and the caffeine content remaining is therefore unknown, the following method has been shown to significantly reduce caffeine in tea:

1. Select your favourite tea and place in an infuser (in a cup or a teapot)
2. Boil fresh water (to ~80oC for green, 100oC for black)
3. Pour water over tea leaves
4. Count/set timer for 30 seconds
5. Pour away/discard this first brewed tea
6. Pour over freshly heated water (to ~80oC for green, 100oC for black)
7. Steep to desired stength.

It has been reported that the caffeine molecule exit the tea leaves within 30 seconds of brewing, so the brew you make from step 6 onwards should be a largely caffeine REDUCED cup of tea.

The art of tea suggest that you not to drink caffeinated teas (or other caffeine containing beverages) after 3pm due to the time caffeine takes to dissapate from your body of which can influence your quality of sleep.

Read here to learn about caffeine quantities in tea.

If you would like to listen to an ABC radio interview with Samantha on decaffeinating teas, then listen here.

Read about Rooibos that is natually cafeine free here
Read about caffeine quantities in tea here