In this blog post we will examine Purple Tea, a cultivar developed in Kenya that is much more than just a fancy name. Whilst in Kenya recently I met with the scientists behind this fascinating project, as well as seeing the developed plants growing in the fields and tasting the finished product.
Firstly a little background. Tea is made from the leaves of the Camellia sinensis plant. From this crop species of the genus Camellia many so called ‘cultivars’ have been created. A cultivar is a ‘cultivated variety’ that is produced by selective breeding. This sounds much more scary than it is. In fact most of the worlds crops are cultivars that have been chosen for their favourable characteristics, such as high yield, pest resistance or desirable colours.
SO WHAT IS PURPLE TEA? Purple tea is so called because it has purple leaves. More specifically it is cultivar TRFK306, developed over a period of twenty five years, which naturally produces ‘brick-red pigment’ in the leaves. According to Lilian C. Kerio (a biochemist at the Tea Research Foundation of Kenya and one of the project’s scientists) this colour is attributed to the leaf pigment anthocyanin. It is this pigment which makes purple tea extra special.
My visit to Kenya came at the end of a long dry spell. The purple tea plants such as the one pictured lose a lot of their purple colour when there is drought but you can still pick it out here.
This led me to question the scientists at the TRFK about the best processing and brewing practices for purple tea. They informed me that to maintain the maximum health benefits from the finished tea the processing must involve minimal heat and exposure to water. This should therefore be those methods used for making white tea or pan fired green. The use of steam such as in the process used to make Japanese teas should not be used. The lengthy oxidation process of black tea would also depreciate the presence of anthocyanin. Brewing should also be cooler than a black tea and for a shorter time. They recommended 80°C for 1 minute. From my research I have discovered that these recommendations are not always those that have been followed. Indeed from the samples I gathered on my recent trip I have purple tea examples that have had oxidation stopped by both steaming and pan firing like green teas, as well as a few that are fully oxidised and rolled in the style of black teas.
WHY IS PURPLE TEA WORTH INVESTIGATING FURTHER? I will firstly start with you, the tea-drinker. How do you, the tea drinker, benefit? Well, firstly in the taste. Our main concern with all of our teas, after their provenance, are that they taste great. If processed, brewed and served correctly purple tea is distinct and delicious.
That leads us on to health and back to the topic of Anthocyanins mentioned above. Ultimately health is the reason why Purple tea has been developed. For us as a tea merchant, this has to be in additional benefit to the taste and experience, rather than the primary reason for drinking.
On top of the discussion above, purple tea has been linked to specific health benefits. Lilian Kerio et al write in their paper ‘Purple tea’s health benefits include antioxidant, anti-inflammatory, antimicrobial, and anticancer, induction of programmed cell death in cancerous cells, protection of cells against induced oxidative stress, improvement of vision and neuroprotective and reduction of the risk of coronary heart disease.’
Each one of these benefits is referenced to a separate paper on the subject. Discussion of these individually is beyond the scope of this blog, but please read up further if you desire. However, in a general there is still limited research into how anthocyanins behave in speciality orthodox loose leaf tea. Much of the research is into CTC (crush, tear, curl) processing, which will produce different results. Despite this the potential benefits seem clear and plausible.
In addition Lilian stated that the caffeine content in purple tea is much less than green and black. For those that are looking for this, you won’t get many teas lower.
The benefits of this tea do not stop here, as we have not yet talked about the farmers and makers. During my visit to the TRFK Lilian went on to state that the plant is ‘high yielding, highly resistant to pests, diseases, frost and drought.' Purple tea is widely adaptable and suitable for all designated tea growing regions.’ Clearly very positive factors for the farmer. In addition to this is the financial benefit. From talking to small holders growing purple tea and the factories buying it, it is also the case that a higher price is being paid for each crop.
So purple tea offers a crop that requires no extra resources to cultivate and offers benefits on every level. The new plants themselves are being provided by the TRFK, so the farmers don’t have to start propagating their own. The only major issue is having available land to start growing purple tea. This can either come by expansion or the replanting of a section of a holding. This puts this section of the land out of action for around three years, which if managed correctly may not be too much of a loss.
Photo courtesy of Kenyan Tea Research Institute
The next stage are the factories, the processors of the purple leaf. As I mentioned in my last blog the tea we will buy from Kenya will come direct from small producers or from factories that are supplied by smallholders. How does purple tea benefit them? Well, in the normal system this is down to the price which they can achieve through the sale of the finished tea. For this to be realised the product has to be processed properly. As discussed earlier this is achieved in a different way to what the majority of factories are used to. Therefore there needs to be extensive training to ensure that the reasons behind the development of this specific tea are not lost.
In Conclusion : There is still a great deal about Purple tea that is not known. It is an intriguing product and one that ultimately has a great flavour and health benefits. I feel that we now have the knowledge to work with our contacts in Kenya to bring a purple tea to our teapots and shelves that will demonstrate its full potential. Stay tuned!