Many of our customers are looking for either caffeine free or decaffeinated loose leaf tea, so we thought it would be useful to produce a short blog post explaining the difference between the two and also the different methods of decaffeination and how you may be able to tell the difference just by tasting them. A naturally caffeine free ‘tea’ or infusion is one that has never contained caffeine.
Probably the most well-known is Rooibos also known as RedBush, Red Tea or or Rooibosch. As well as being caffeine free, it is also low in tannin. Rooibos is not related to the tea bush (Camellia sinensis ) but is actually a member of the broom family and grows primarily in Cederberg, in the Western Cape province of South Africa.
Another caffeine free alternative to tea is Honeybush, similar to Rooibos, also low in tannin, but slightly sweeter, it only grows in the southeast and southwest of South Africa.
Other caffeine free alternatives are usually referred to as herbal teas, such as Peppermint, Chamomile, Hibiscus, Nettle, Raspberry Leaf, to name a small selection or fruit infusions or Tisanes (the definition of tisane being a water based infusion from herbs, spices and / or fruits).
As the name implies, a decaffeinated tea is produced using the leaves of the tea plant (Camellia sinensis), but the caffeine has been removed using one of 4 processes.
Using this method, caffeine is removed by soaking tea leaves in methylene chloride directly or indirectly, by soaking the water (used to remove the caffeine) in methylene chloride and then returning the water to the tea for re-absorption of flavours and oils. In some countries it is forbidden to import teas treated this way. Methylene Chloride is used in a number of industrial processes, including paint stripping and metal cleaning and degreasing.
The solution also used as a solvent where caffeine is extracted in the same way as with methylene chloride processing. Tea processed using ethyl acetate may be referred to as “naturally decaffeinated” because ethyl acetate is a chemical found naturally in tea. However, with this method of decaffeination, ethyl acetate is very difficult to remove after the decaffeination process, and people sometimes describe tea treated this way as having a chemical taste. Ethyl Acetate is also a chemical used in producing glues and nail polish remover.
Carbon Dioxide (CO2)
This is the method that is used to decaffeinate all Carslake Tea Company tea blends. It is also known as a natural method of decaffeination and it is the safest form of decaffeination that still retains the tea flavours and health benefits. How tea leaves are normally treated with this method is basically “pressure cooking” them with this naturally occurring gas. When the CO2 becomes a solvent, its small, non-polar molecules attract the small caffeine molecules and removes them from the tea leaves. As flavour molecules are larger, they remain within the leaves, retaining the natural flavour.
Water Processing Decaffeination
Caffeine extraction with water is not a primary method of tea decaffeination. Although it is a more popular method of coffee decaffeination, only a small amount of tea products are decaffeinated using this method. After the caffeine is removed from the tea by soaking the tea in hot water for a period of time, the solution is passed through a carbon filter for caffeine removal. The water is then returned to the tea for re-absorption of flavours and oils. Some people who have drunk water process decaffeinated tea have said it tastes weak and watered down.
It is worth noting that even decaffeinated tea is not 100% caffeine free and will usually retain between 1% and 2% caffeine.