Fresh tea leaves
Before fresh tea leaves are processed, they undergo a preliminary sorting step, during which dirty, diseased, etc. tea leaves are rejected. Sometimes, at the same stage, the highest quality flushes for elite teas are selected.
This sorting is done only manually.
Wilting
The main objective of the fading stage is & mdash; dehydration of tea leaf. In the process of withering, the leaf loses up to 55% of moisture.
Tea leaves are withered, usually in shade, in a well-ventilated room (or under awnings), but some varieties are also withered in the sun.
Tea withering can be natural, and then it lasts from 10 to 24 hours, or artificial, and then in special dryers the withering time is reduced by 3-5 times compared to the standard one. The time of withering largely depends on the surrounding conditions (air humidity, temperature, wind, etc.) and on the variety we want to get.
In addition to simple dehydration, at the stage of withering, another very important thing happens: the cell turgor (pressure) subsides, the leaves become more elastic and less brittle. In addition, the juice of tea leaves becomes more viscous, thick.
All of these processes guarantee quality twisting and fermentation in the future.
The quality of wilting is usually determined by the degree of weight loss of the starting material, but the standards in different regions are different. For example, in northern India, 40% is considered good weight loss when withering, and in southern India and Ceylon & mdash; 50%.
Sun fading
For withering, tea is usually laid out in a thin layer (up to 12 cm) in baskets, or on special pallets, which can be multi-storey, such as stacks.
In modern withering technologies, synthetic nets are used to unfold tea, which are set in motion (tea is shaken for more uniform withering), in addition, artificial air injection of the desired temperature and humidity, etc. is used.
Indoor fading
For withering, freshly picked leaves are scattered in a thin layer on special lattice racks in a warm ventilated room and left in this position for 8-10 hours until they become soft (withered). Throughout the drying process, the leaves are turned over with the hands, thereby partially disrupting the structure of the tea leaf cells, allowing air to enter, and creating favorable conditions for the fermentation process.
Processing
Tea processing depends on what they want to get The best varieties are produced by hand by skilled tea farmers, whose skills are honed and passed down from generation to generation.
Immediately after the tea leaf is torn off, it undergoes an oxidation process and changes color from green to brown.
The degree of oxidation, or, as it is correctly called, withering, depends on what kind of tea we want to ultimately get.
In each method, the tea master's talent lies in releasing the right amount of catechins, flavonoids, which, due to their antioxidant properties, determine the taste characteristics of future tea.
Shaking in baskets
After withering, tea leaves are shaken in bamboo baskets to slightly wash the edges.
Then they are alternately shaken and laid out for drying until the surface of the sheet turns slightly yellow and the damaged edges become slightly rusty (as a result of reaction with oxygen).
CTC (Crush Tear Curt with Full Fermentation)
CTC tea goes through three stages of machining during the manufacturing process, which are reflected in the name Cuts Tears Curls, which translates as: & laquo; crush, crush, twist & raquo;.
Twisting tea by machines, labeled as & laquo; CTC & raquo; and clearly illustrates the process of preparing teas from low-quality leaves, usually machined.
Most tea connoisseurs are contemptuous of CTC teas, as this process is fundamentally opposed to the careful handling of high-quality tea during its preparation.
But CTC has an important role in tea production: since it is & mdash; a fully mechanized process that produces large quantities of tea very quickly, as well as handling raw materials that were previously discarded.
In addition, CTC technology has a certain advantage, allowing you to make the strongest teas with a high caffeine content, even from mediocre leaves.
Machines quickly press the subverted tea leaves, squeezing out most of their juice; then they strongly grind (cut) the leaves and in the final stage roll them tightly into granular balls, strongly resembling instant coffee in appearance.
The tea pellets are then oven dried or dehydrated (dehydrated) in any other way.
Fermentation
The term & laquo; fermentation & raquo; First used in 1901 as the name of the oxidation process started by tea enzymes.
Most of the chemical transformations that occur in the manufacture of tea fall into the fermentation process.
The biochemistry of fermentation is quite complex, but in short, it can be described as the oxidation of a mixture of tea polyphenols and tea enzymes (enzymes) that activate this process. The result of this process is the formation of theaflavins and thearubigins (giving the infusion of black tea its characteristic red-brown color).
For direct fermentation, tea leaves are transferred to large cool, damp and darkened rooms, where they are laid out on a flat surface in layers about four inches (10 cm) thick. The surface should not chemically react with tea phenols, and usually aluminum sheets or specially treated wood are used for this.
The ideal combination of conditions for quality fermentation is to combine the lowest possible fermentation temperature (about 15 & deg; C) with the highest possible air humidity (about 90%). It is not as easy as it seems, because in those places where tea grows, such a low temperature & mdash; 15°C — almost never!
Fermentation can last from 45 minutes to several hours. This depends on a combination of many conditions: the initial temperature of the tea leaf after twisting, the degree of its humidity after withering, the humidity of the air and the features of airing the fermentation room, etc.
During fermentation, the color of the leaves darkens significantly (turns brown), from fermentation and sublimation & laquo; squeezed & raquo; tea juice, characteristic aromas of black tea appear & mdash; ranging from floral to fruity, nutty and spicy.
Here it is important to remember that the fermentation process must be stopped precisely at the moment when the aroma of tea reaches optimal condition. To stop fermentation, proceed to high temperature drying.
Partial fermentation
Partial fermentation is achieved by rapidly drying green leaves immediately after harvesting or slowly wilting at low temperatures. To stop the oxidation process, Oolong and Black Tea leaves are crushed and rolled to achieve semi-fermentation or complete oxidation.
Light teas are considered the mildest and lightest because they have undergone partial fermentation, which is otherwise called semi-fermentation.
Complete fermentation
Complete fermentation is achieved by holding tea at the lowest possible temperature (about 15 & ordm; C) of fermentation with the highest possible humidity (about 90%) for a long time. It is not as easy as it seems, because in those places where tea grows, such a low temperature (15 & ordm; C) & ndash; almost never! Fermentation can last from 45 minutes to several (3-5) hours. This depends on a combination of many conditions: the initial temperature of the tea leaf after twisting, the degree of its humidity after withering, the humidity of the air and the features of airing the fermentation room, etc.
We also add that along with classical fermentation, when tea is aged until an expert comes and says "Enough!" there is also conveyor fermentation. In conveyor fermentation, time is standardized & ndash; tea moves very slowly along the conveyor towards the dryer.
During fermentation, the color of the leaves darkens significantly (turns brown), from fermentation and sublimation & laquo; squeezed & raquo; tea juice, characteristic aromas of black tea appear & ndash; ranging from floral to fruity, nutty and spicy. Here it is important to remember that the fermentation process should be stopped exactly at the moment when the aroma of tea reaches optimal condition.
To stop fermentation, proceed to high temperature drying.
Pinning
Drying is an important step in tea production. It is necessary to interrupt the biochemical processes during fermentation in time and consolidate the desired properties of tea.
Steaming
Steaming is mainly used in the production of white tea to stop the fermentation process. Usually this is a kind of & laquo; burning & raquo; lasts about 1 min.
Pan
Panning is usually used to inhibit fermentation. This process is usually used in the manufacture of oolong. In this case, preliminary drying is carried out at a temperature of 250-300 degrees for 15 minutes. You can repeat the pan process several times as needed, alternating it with the twist process.
Baking
Firing (or high temperature drying) is used to stop fermentation. This is the only way to prevent tea from becoming moldy and rotting under the influence of its own juice.
The roasting process is very delicate, as under-dried tea deteriorates quickly, and over-dried tea is charred and acquires an unpleasant burnt taste. Ideal drying result & ndash; dry tea raw material, which contains not more than 2-5 percent of water.
Traditionally in ancient times, tea was fired on large baking sheets, grates or pans over an open fire. Since the end of the KhІKh century, closed air-blown ovens have been widely used. Standard firing temperature & ndash; about 90 degrees Celsius but in modern equipment, the firing temperature can reach several hundred degrees. In this case, the firing time is reduced to 15-20 minutes.
An important condition for the correct manufacture of tea is also the rapid cooling of tea raw materials immediately after removal from the oven (like any organic substance, tea can begin to smolder and & laquo; burn out & raquo; even after removal from the oven). So, the leaves are dried in large ovens in a stream of hot air under the influence of high temperatures. The tea juice released during twisting and its aromatic essential oils firmly & laquo; boil & raquo; to the surface of the leaves and retain their properties for a long time, extracting only under the influence of boiling water at the time of brewing.
Yellowing
Yellowing is mainly used in the production of yellow tea, in the technological chain of which there is a stage of languishing, in which tea leaves gradually turn yellow under the influence of moisture and heat.
Steaming out
Tea leaf is fixed by steaming at 95-100 & ordm; C for 5-10 minutes. The steaming method consists in the fact that a basket filled with a sheet with a perforated bottom is placed for half a minute at some distance from the surface of boiling water. This operation is carried out very carefully, since insufficient steaming can affect the aroma and other properties of tea.
Shaping
Shaping a Tea Flower sheet should occur immediately after roasting.
It is important to remember that the temperature should not drop at all, i.e. not a single second should be lost.
This often requires the interaction of more than one worker. There are two ways to twist tea leaves: machine and manual.
At machine - twisting is performed in special devices & ndash; rollers.
Twist technology varies greatly depending on the quality of the raw material and the pretreatment.
At the same time, the degree and method of twisting significantly affect the quality of the tea itself.
The easily twisted tea leaf is brewed rather weakly, while the highly twisted leaf gives a strong infusion.
Each manufacturer independently determines the number of twisting steps. One stage takes an average of 40 to 45 minutes. Typically, the entire shaping process takes about 2 hours.
For the correct development of oxidative processes accompanying twisting, a special temperature (22-26 degrees) and humidity (96-98%) conditions are established in the roller shops, and perfect purity is maintained.
If the river method of shaping is used in production, tea leaves are promptly placed on woven bamboo trays with edges. To shape & laquo; rou nian & raquo; the leaves are rolled out on a tray and massaged as it were.
Tea leaf shaping is necessary for several reasons. Firstly, with the help of it, the leaves dry in a twisted form, which is beautiful and saves space for packaging. Secondly, & mdash; the sheet's friction against the uneven woven bamboo surface disrupts its cellular structure.
Collectively, the twisted shape and damaged structure will result in slow release of essential oils, flavor and aroma when brewing tea. The taste, depth and aroma of tea, all this should gradually open up in the same way as tea leaves unfold in a teapot. Crushing changes the process of tea oxidation at the remaining stages of production, as well as when the tea is ready.
Twist
Twist Task & mdash; Squeeze as much tea juice as possible from tea leaves.
In addition, it was found that when twisted, tea polyphenols are mixed with tea enzymes, which is a prerequisite for normal fermentation.
Twisting can be done manually, and such tea is called orthodox (labeled as & laquo; ortodox tea & raquo;), or by machine. Machine-rolled tea is labeled as & laquo; CTC & raquo; (cuts, tears, curls), which in translation is called: & laquo; crush, grind, twist & raquo; and clearly illustrates the process of preparing teas from low-quality leaves, usually machined.
Hand-curling is perhaps an even more time-consuming process than hand-picking tea. The procedure is as follows: the & laquo; tortilla & raquo; from subverted leaves, about a centimeter thick, curls into a sausage, and begins its rolling.
The most suitable analogy here is & mdash; rolling dough, such as for dumplings.
Rolling is rarely performed on weight, more often on the walls of vats/baskets, or on special tables or boards resembling wavy washboards.
Twisting (aka rolling) should continue until the leaves turn from green to dark green, that is, they do not get wet, they are saturated with their own juice.
This is quite a challenge.
Easy twisting
Tea obtained by a slight twist, when brewed, gives a weak infusion, and tea from highly twisted raw materials has a rich strong mood.
Ball twisting
Rolled tea is rolled into a small ball by hand, after which it looks like a pearl. The stronger the ball is twisted, the greater its extractiveness.
Molding/Pressing
In the form of pressing, teas are tiled, brick and tableted. Tea in the form of tiles should have a smooth surface without cracks and broken edges and corners, sufficient fracture strength.
Its humidity should not exceed 9%. Depending on the variety, the caffeine content must be at least 2.2% in the highest grade, at least 1.8% & mdash; in grade 3.
Accordingly, the content of tannin should be at least 9.1 and 8%. Thanks to pressing, which limits the free access of air to the contents of the tiles, pressed tea retains its original properties longer during storage and is convenient for transportation.
Black tiled tea is produced only in Russia and China.
For the production of brick tea, raw materials are coarse and old leaves and shoots of late autumn picking or spring pruning of tea bushes. The production technology includes two stages: preparation of a semi-finished product & mdash; laocha (translated from Chinese "old tea") and pressing brick tea from it.
Classical laocha production technology is characterized by an extreme duration of the production cycle (15 & mdash; 20 days). Pre-steamed laocha is pressed on hydraulic presses under a pressure of 8 MPa.
At the bottom of the mold containing 2 kg of laoch, first steamed facing material is laid? tea leaf of the 3rd grade (200 g), then the mold is filled with an internal material containing at least 70% of the leaf and not more than 30% of green and lignified shoots (1600 g in total), and the facing material (200 g) is placed on top of it again.
The brick-pressed tea cools in molds for an hour and is then dried at 34 & mdash; 36 & deg; C and relative humidity 50 & mdash; 55% for 15 & mdash; 20 days to humidity 11 & mdash; 12%. Finished bricks have a standard size of 35.75x16.15x3.6 cm and weigh about 2 kg.
Each brick must have a clear imprint of the trademark or brand. When released from teapot factories, bricks are wrapped in paper and placed in standard boxes of 20 each.
Tabletted tea is a type of pressed tiled tea. Its feature is the low weight of tablets (3 & mdash; 5 g) and the high quality of raw materials & mdash; tea crumbs from higher varieties of tea, ground into a thin powder. Sometimes this powder is not pressed, but placed in small non-soaking porous paper bags for one or two infusions.
Mainly black tea is tableted. Tableted with excipients is also produced. milk, sugar, lemon, or dietary supplements.
Drying
Drying tea leaf at high temperature & mdash the only way to stop the fermentation process.
If this is not done, the tea will simply become moldy and rot.
This process is delicate, because if the tea is not dried & mdash; it will quickly deteriorate in packs, if it is dried out, it will simply char and acquire a disgusting burnt taste.
Perfect drying result & mdash; dry tea raw material containing not more than 2-5% of water.
Traditionally, in ancient times, tea was dried on large baking sheets, grates or pans over an open fire, as it were & laquo; roasted & raquo;. Since the late 19th century, closed air-blown ovens have been widely used. Standard drying temperature & mdash; about 900 & deg; C, but in modern equipment the drying temperature can reach several hundred degrees. In this case, the drying time is reduced to 15-20 minutes.
An important condition for the correct manufacture of tea is also the rapid cooling of tea raw materials extracted from the oven. The leaves are dried in large ovens in a stream of hot air at high temperatures. The tea juice released during twisting and its aromatic essential oils firmly & laquo; boil & raquo; to the surface of the leaves and retain their properties for a long time, extracting only under the influence of boiling water at the time of brewing.
Heat treatment
The heat treatment process is different, which brings a pleasant variety to the flavors of tea. There are three different types of teas depending on the method of thermal exposure on the freshly picked sheet:
- Roasted teas. The most famous of the roasted teas & mdash; this is Long Jing, Dong Ting Bi Luo Chun.
- Teas that are dried in an oven or in a special appliance like an oven. Of these, the most famous are Huang Shan Mao Feng, Tai Ping Hou Kui.
- Steamed tea that is steamed and then rolled. Teas produced using this technology are characterized by a delicate aroma with floral and fruity notes and a mild taste (Spindle Jade, Spiral Jade, Xue Hua).
Natural aging
The method of natural aging consists in the fact that the prepared tea leaf is collected in a heap and left for a long time (on average up to 10 years) in ventilated rooms with high humidity and stable temperature conditions.
Over time, tea juice begins to be released, and the leaves, under the influence of moisture and produced substances, undergo natural fermentation.
Wet Lay-up
Wet stacking (used mainly for Puer) means storing tea in a wet warehouse; long term. With this method, the effect of natural aging is also achieved. And tea takes on a specific raw taste.
Mixing with flowers and fruit
Mixing tea with various herbs, flowers and fruits is carried out in a special mixing (blending) drum. According to strict recipes, tea is made here that meets the standards of a particular variety.
After the tea has been dried and cooled, it is sorted, labeled and packaged. Sorting of ordinary teas is usually carried out by machines (according to the principle of ordinary sieving), and high-quality teas can be done manually.
After sorting, tea is evaluated and labeled.
It should be noted that this is only a preliminary assessment of the size of the finished tea, however, it does not take into account its taste at all.