STiR coffee and tea magazine

36 STiR coffee and tea / Issue 3, 2017 (June/July) SFTGFOP1 and 'Purple Mist', made from purple tea cultivars. The first stage of the process for both CTC and orthodox teas is wither- ing and, whereas most factories spread the tea out by hand in long troughs and then leave it to evaporate a percentage of its water content in uncontrollable ambi- ent conditions that can vary according to the climate and time of year, Emrok uses an automated bulk withering machine. This allows controlled withering, regard- less of climate and ambient humidity and temperature, and ensures consistently bright liquors. The machine is mechani- cally loaded and holds the leaf for about 14 hours in an enclosed tunnel where the initial process, involving controlled air passage and critical temperature monitor- ing, achieves the chemical aspects of the leaf's wither. This is followed by a rapid moisture loss process that achieves a predeter- mined moisture level in the green leaf. For the CTC teas, the moisture level is reduced to 68% and for orthodox to 58-60%, while shufflers inside the tunnel tumble the leaf to ensure an even wither. From the withering tunnel, the leaf is passed along conveyor belts to either the CTC cutters or the orthodox rolling machines. Anand Varma, technical consultant for specialty tea manufacture at Emrok, designed the layout, has taught staff aspects of orthodox tea manufacture that they previously did not think were possible, and he oversees the continuous batch processing of the orthodox leaf. Handling of the leaf is kept to a minimum and, after rolling and oxidation, the tea goes into a vibrating fluid bed dryer that has an output of 400kg per hour. Finally, the dry leaf is sorted into 13 different grades by an automated color sorter. Purple tea As in other parts of Kenya, farmers are now growing the purple cultivar that has been bred for its high levels of antioxidant anthocyanin, a polyphenol found in purple foods such as blueberries, purple sweet potatoes, black grapes red cabbage, and now also in this new tea clone. The 'purple' cultivar (TRFK 306) was developed more than 25 years by the Tea Research Foundation of Kenya (TRFK) and was released to farm- ers in 2011. The biggest challenge faced by growers and processors when they first grew it was the very bitter and as- tringent taste of the tea liquors caused by the high level of polyphenols in the green leaf. Emrok has planted a division of the Ogirgir estate with the cultivar and the factory has a separate section for the pro- cessing of the fresh leaf. Purple tea is only made to order since a mainstream mar- ket for the new tea is not yet established, and Emrok only produces between 100 kg and 200 kg per day. Robert Keter be- lieves that production of this type of tea is "the way to go to secure Kenya's tea industry. There is a market for purple tea. It's particularly well received in Asia." Fully automated orthodox manufacturing production line Emrok operates one of Kenya's most modern tea processing facilities Tea plants are harvested all year long

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