History of Tea Cultivation and Processing
Tea is an evergreen plant, camellia sinensis, that grows wild in tropical climates and is indigenous to both China and India. It needs heavy rainfall of at least 100cm per year but deep, light, acidic, well drained soil. Providing these conditions are met it can grow up to 2100ft above sea level. Although there is reference to drinking tea far back into China's history, these are vague and not differentiated from other leaves boiled in water until 350CE when it acquires it own character. The first people to drink tea are mentioned as hillmen in south west China who would pick the leaves from the wild and boil them fresh to make a bitter, medicinal brew. It was around this time that the first plants were most likely cultivated and since then the methods of cultivation and preparation have changed dramatically to produce the drink we know today.
The first thorough description we have of early Chinese tea cultivation methods come from the Ch'a Ching, the Classic of Tea, written by Lu Yu around 760 CE during the Tang dynasty. By this time tea had already become a significant plant in Chinese culture, having been processed into blocks and traded with Turkish merchants along the Mongolian border for around 200 years, but the methods used are unknown or inferred to be prototype versions of those outlined by the Ch'a Ching. Lu Yu was an orphan who was raised in a temple where tea was grown and probably spent many hours in tea fields. He turned against his spiritual upbringing and left the temple to become an entertainer, then a government official before returning to his roots, becoming a scholar on tea and making implicit suggestions that tea was more than just a beverage but a spiritual practice as well.
Lu Yu's early descriptions of tea production list the 8 tea producing regions of Tang dynasty China together with their gradings and quality comparisons from each. He also lists the ancient tools and techniques used for picking, firing and storing tea that give us our first insights into methods of tea processing. The first of these is the “ying” (籯), a simple bamboo basket, between 2-6 litres in capacity for collecting freshly picked tea leaves on a sunny day. It had to have have good ventilation to keep the leaves cool and prevent the oxidation process. Next was the “zao” (灶), a stove for burning logs, without a smokestack on which would be placed on a “fu” (釜), a kind of cauldron or kettle made of iron, copper or clay with a lip to prevent smoke from getting into the leaves from the stove. The leaves would be placed on top of this in a wood or clay steamer with a bamboo slat called a “zeng” (甑). A little water would be added to the zeng to provide continuous steam and the leaves spread out using a three pronged fork allowing them to cool and keep the juices from escaping.
After steaming the leaves were crushed in a pestle, called a “wu jiu” (忤臼) or a “dui” (碓), that should be well seasoned by frequent use, and then pressed into cakes using a mould known as a “gui” (规), “mo” (模) or “juan” (桊) that could be square, circular or in fancy geometric shapes. The pressing would be done on a table called a “cheng” (承) made of stone or wood and covered with a “chan” (檐), a tablecloth to collect dropped leaves. Stone cheng were preferred for stability although wooden tables were acceptable if they had their legs half buried in the soil to ensure a steady work surface.
Once the cake was made it had to be dried in a sieve called a “bi li” (芘莉) around a meter wide. When it was partially dry a “qi” (棨), a small cutter with a wooden handle, was used to poke holes in the compressed cakes and bamboo strips called “pu” (扑) or “bian” (鞭) were threaded through the holes and used to suspend several tea cakes like a string. Finally came the firing process, where the cakes were transferred onto skewers called “guan” (贯) and mounted on wooden shelves or “peng” (棚) over over an underground fire pit called a “pei” (焙) where the leaves were fired. The peng had two shelves and the tea would start on the lower one before being moved up higher for final drying.
The last tools mentioned by Lu Yu were for the buyer and seller, a “chuan” (穿), a string like material for measuring quantity whose actual measure varied from region to region, and a “yu” (育) meaning cultivator that was a wooden warming cupboard with bamboo shelving and a small flame at the bottom used for people living in the wet regions to keep their tea dry during rainy seasons. It would then be boiled up in salted spring water, sometimes with additional flavouring from orange peel, jujube berries, onions, ginger or peppermint but never with milk or sugar and served in glazed cups or bowls.
In the Song dynasty (960 - 1279CE) every aspect of tea was further refined. Harvests became carefully regulated affairs with specific days chosen to harvest the leaves at their peak by young girls who had to keep their fingernails at a length where they could pick the leaves without them touching the skin. They worked to the rhythm of a cymbal or drum: picking, sorting into grades and pressing into cakes. The highest grades would be sent to the emperor as tribute and could be priceless while the grades immediately underneath would be worth several pieces of gold. During this time a new style of preparing “whipped” tea came into fashion causing the equipment and methods to change accordingly. In this second school of tea the leaves were ground into fine powder in a small stone mill and hot water poured onto the powder, left to brew and then whipped until it formed a frothy head. This method is still popular in Japan, as it was during this period that tea was reintroduced to Japan by a Zen Buddhist monk that had been studying in China, and the Japanese tea ceremony was born. Salt and all other traditional additives were done away with completely as the Song emperors wanted to taste the natural delicacy of the tea. The only remaining additive was some flowers such as jasmine creating the first flower teas and the first practices of ageing.
After the Songs, the Mongol Yuan dynasty took over and tea fell out of favour with the new court but it enjoyed a revival with the return of the Chinese Ming dynasty (1368-1644) who sought to revive all things Chinese, including tea. It was during this period that the fermentation techniques used to make black and oolong teas were developed. This is achieved by leaving the leaves out to oxidise before drying and is thought to have been discovered by accident although it is also possible that they were deliberately created through experimentation by the emperors tea gardens. These enabled tea to be subdivided into six different groups: green, oolong, black, white, compress and flower scent tea depending on its colour or processing procedure.
Another significant change in the production of tea during this time was the popularisation of loose leaf tea after compressed cakes fell out of fashion. In 1391 Emperor Zhu Yuanzhang issued a decree that loose leaf tea should paid as tribute instead of cakes in order to combat corruption in the tea trade. Tea cakes were frequently used as currency in China and the emperor wanted to make it less currency ready so it was not so easy to counterfeit. This would both protect the economy and preserve the taste of tea from being mixed with other leaves and spices in order to extend its value. With it came a change in the methods of picking and brewing tea. Now only tender leaves from flushing buds were used and infused into heated spring water. It was considered to be a simpler, more natural technique and bring out the true flavour of the tea. Along with these new methods a new age of innovation in tea culture was born. One of these innovations was the teapot, made of zisha, or purple clay, which slowly evolved out of the bowls used for drinking powdered tea and into the forms we are familiar with.
The Qing dynasty (1636-1911) sees tea production settle down to the form most like we know today. By now tea has nine major stages that vary only slightly for each type. First the leaves are picked during early spring and early summer or late spring before being left to wilt and oxidise under the sun or in a breezy room until they reach the correct moisture level. Next they may be bruised by tumbling in baskets or being kneaded or rolled over by heavy wheels to aid further oxidation before being left in a climate controlled room until they reach the desired level of darkness. This happens as the chlorophyll in the leaves is enzymatically broken down and the tannins are released or transformed. The level of oxidation varies according to the type of tea being made, from 5-40% in lighter oolongs, 60-70% in darker oolongs and 100% in black tea. White and green teas are not oxidised at all and skip the bruising and oxidation stages. Next the tea is fixated through a method called “shaqing” (殺青) that literally translates to kill-green. This is accomplished by moderately heating the tea leaves, traditionally panned in a wok or steamed but also more recently by baking in a rolling drum, in order to deactivate the oxidative enzymes without destroying the flavour of the tea. Some white teas and modern black teas combine this process with drying. Yellow teas then undergo a sweltering phase where the warm and damp leaves from the kill-green process are lightly heated in a closed container causing them to turn yellow. Then they are rolled into wrinkled strips and may be turned into spirals, balls, cones or other elaborate shapes before finally being dried, usually by baking, but also panning, sunning or air drying. Now it is ready to be sold. Some speciality teas such as puerh or flavoured and scented tea are aged further, with secondary fermentation, baking, or being sprayed with aromas or flavourings before being dried again. All these processes have to be carefully controlled to prevent fungus growing on the warm, damp tea which will render it unfit for consumption.
It is around this time that tea first becomes available in Europe and soon British pioneers begin to search for ways to cultivate the crop in Empire controlled countries. Initially tea was almost exclusively bought from China. The East India Company's monopoly on goods from the east made this a lucrative deal for both sides, providing the Chinese with a stable export and the East India Company with a guaranteed quality product but it was a bad deal for the British consumers at home and they soon realised this when they compared London's tea prices to America and Australia which were enjoying free trade relations with China. It was partially due to this merciless fleecing of the English public that the East India Company's trading functions were abolished in 1834 and the commanders of the British colonies in India were quick to look for alternative cheaper sources of tea without having the depend on the Chinese.
India proved to be a fertile ground which already had its own indigenous wild variety of camellia sinensis rumoured to be growing in the jungles of Assam. A man named Charles Bruce found some of these plants, had them identified as a species of camellia sinensis, but different from the Chinese variety. He returned to the jungle and found some of these plants growing wild, cleared the area around them and allowed them to grow. By 1838 he had harvested his first crop and shipped 12 chests of Assam tea to London. The novelty proved a success and the Assam Company was formed recruiting planters to immigrate to India and begin plantations. This was no easy journey with a 6 month voyage to Calcutta, followed by a twenty to thirty day trip up the Brahmaputra river and then a elephant ride through the jungle to the plantation where accommodation was just simple huts with little or no furniture, but the promise of easy success ensured plenty of volunteers.
Unfortunately the secrets of producing a truly great tea was still in the hands of the Chinese. The task of uncovering these secrets fell to Robert Fortune, a Scottish botanist, who disguised himself as a Chinese merchant and travelled around the empire with Chinese friends in 1848, visiting factories and plantations, buying seeds forbidden to be sold to outsiders by the Chinese government and sometimes even making notes from his sedan chair as he passed by. He brought these seeds and seedlings back to India using Wardian cases, small portable greenhouses, and introduced them to a new plantation of camellia sinensis founded by a Dr. Campbell in Darjeeling. Darjeeling proved to be a much better ground for breeding Chinese tea which did not fare well in the lowland jungles of Assam. This region has produced some of the finest Indian teas and is often considered to be for tea what the champagne region of France is for wine.
The British drive to find new lands to grow tea continued into Ceylon, modern day Sri Lanka. Coffee had been grown on this island since 1830 and was firmly established as the worlds finest but in the late 1860s a disease called “coffee rust” struck the plantations and decimated them. Thus when a Scotsman called James Taylor cleared and planted 21 acres of tea on Loolecondra Estate no one could have guessed how important his actions were. Tea quickly supplanted the ailing coffee crop and became the largest export of Ceylon upon which the country has relied upon through several changes in state and one change in name.
Another element that the west introduced to tea cultivation and processing was the use of industrial machinery, modern scientific techniques and technological innovations to the preparation and sale of tea. One of the most significant of these was the tea bag and accompanying the tea bag came a new method of processing called “crush, tear, curl”, also known as “cut, tear, curl” or CTC for short. This method was invented by W. McKertcher in 1930 and involves passing the leaves through a series of cylindrical rollers with hundreds of sharp teeth that crush, tear and curl the tea instead of the traditional rolling. This technique gives a quick and colourful brew that is well suited to tea bags and spread throughout India and Africa in the 1950s through 1970s. Today this makes up 80% of the Indian domestic market, especially in the export markets to major brands of tea bag manufacturers and for use in masala chai where the rich red-brown colour will come through the white of the milk.
The convenience of tea bags has continued to keep tea as the number one drink in the world and now even high grade teas are processed using the modern CTC method as people want quality and convenience combined, but there has also been a resurgence in traditional tea manufacturing methods including the ancient styles of bricks and powdered tea as well as the familiar loose leaf forms. This is probably due to the effects of globalisation and the information revolution of the internet. Today people are becoming more aware of the different styles of drinking tea that have happened around the world and throughout time. They are interested to find new and exciting ways to enjoy their favourite drink. Internet shops allow them to purchase varieties of tea that they may not find in their local supermarket and as the culture grows the major brands are forced to respond. Increasingly we are seeing some of the popular brands sell loose leaf versions and specialist shops appearing on our streets offering teas of all grades and processing styles to meet the demand.