Your cup of tea 4: Modern processing

YUM Eat Cafe - teaThe coming weeks we introduce you to about 25 different natural health teas (without added flavours and other additives). Here the third part of the introduction. All teas at Yum Eat Cafe are served in-fusion.

When tea cultivation began in Assam, Chinese growers came to instruct the planters in leaf preparation,  It was soon apparent that village hand methods were not suited to plantation work, and new processing methods were developed.  In the new withering process, the leaves were spread on trays and left overnight, then rolled only once, and spread on the floor to ferment.  Drying began in a hot iron pan and was finished on trays placed over a charcoal fire.  Hand rolling required the greatest amount of labour.  The modern mechanical roller was developed in Assam in 1887.  In the same year drying machines were produced in which the rolled, fermented leaf, spread on moving metal trays, was subjected to hot air currents. By 1890 the tea factory had replaced the tea house.  The leaf, withered, or dehydrated, on racks for 18 hours, was then machine rolled for about an hour, fermented in a cool, humid room for three to four hours (including the rolling period);  then dried by machine firing.  Mechanical sorting or grading was carried out on wire mesh trays.  Six or more grades were produced, ranging in size from the unbroken orange pekoe to the smaller broken grades, fannings, and dust.

Tea leave withering or wilting has always presented difficulties.  Controlled loft withering was studied in Ceylon, but it was not until 1958 that trough withering was invented in the Congo.  In the trough method conditioned air is forced through a 20 cm layer of leaf, producing an even wither.  In the loft method the leaf is spread thinly, producing a wither that varies widely from rack to rack.  In Assam 100 parts of fresh leaf may lose 30 parts of water during the wither, whereas in Sri Lanka the loss may be as much as 45 parts

In Assam, where natural conditions often discourage withering, the loft is impractical; rolling frequently has to be performed on unwithered  leaf prior to the invention of the trough.  Unwithered leaf does not roll well, and in 1925 the “”unorthodox” procedure was instituted, in which a Legg tobacco cutter was used to shred fresh leaf.  This method makes a cut out 0.08 cm wide, distorting most of the leaf cells, and is followed by a short roll, a brief fermentation period, and firing.

A CTC (crushing, tearing and curling) machine was invented in Assam in 1930.  Normally withered leaf is given a short, light roll, then put through the machine.  Two engraved rollers, one making 70 rpm and the other, 700, distort the leaf in a fraction of a second.  Other machines producing rapid and full leaf distortion have also been perfected.  The unorthodox method is currently applied to 70 percent of the tea manufactured in northeast India, and the method is also prevalent in several other countries.  The grades of tea produced are mainly dust and fannings, with some brokens.

The tea is machine fired, and on the following day it is sorted into grades.  It is then stored in bins until a sufficient amount accumulates to make up an invoice of about 60 to 240 chests.  Tea chests, made of three-ply wood and lined with aluminium foil and rice paper, hold 36 to 50 kg of tea.


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