Have you read the first lesson: What is tea ?
As all tea comes from the same plant, the secrets behind the different types of tea lie in production. The production of tea is associated with a lot of mystery and secrets and each tea master has his own way of producing tea. A tea master is the person who is responsible for production and has extensive training in the subject. Mainly, we divide the production into five basic steps: picking, withering, rolling, oxidizing, heating. Some theme masters do not use all of these and some of them several times.
Of these steps, oxidation is the most important in relation to the type of tea you want to produce. Oxidation is the same as what happens to a banana when it turns black from being left for too long, or to an apple when you remove the skin. The enzymes react with the oxygen after the cell walls have been broken down. To speed up the oxidation, you can beat, roll or cut up the tea leaves so that more cell walls are broken down and the enzymes react faster. What separates the different types of tea from each other is how long, and if, they are allowed to oxidize. When the tea master thinks it is enough, he starts a heating process called "kill green". This heat treatment stops the oxidation and enzyme activity. We can see the same again in an apple that is baked in the oven; it will have the same golden color as when it was fresh because the enzymes have not had a chance to react with the oxygen at all.
Depending on the production methods, we get the different types of tea. We will deal with the most common ones: white, green, oolong, black and pu-ehr.
White tea is the least processed, yet most expensive of all tea types. It is produced in the simplest possible way - picked and dried. From the time the leaves are picked until they are completely dried, they have time to wither a little. The leaves oxidize a little in the display phase, but rarely more than 20%. Traditionally, and most often, the leaves are dried in the sun. If the weather does not allow it, the tea is dried in suitable rooms over machine heat or fire with a drying heat of around 50 degrees.
White tea comes from the delicate, immature bud and/or leaves from the first flush. Due to the minimal processing, white tea retains catechins (antioxidants) and also has a high caffeine content because it consists of fresh shoots. White tea has the same healthy and good properties as green tea. Since white tea is harvested with young leaves, they do not contain the same amount of chlorophyll as green tea and therefore do not taste as vegetal.
A fine white tea has white hairs that cover the surface and often become extra visible on the slightly darker tea leaves.
White tea has the mildest taste of the tea types.
What distinguishes green tea from white tea is that the leaves are roasted or steamed (most commonly in Japan) to kill the enzymes in the leaves so that oxidation stops. Green tea can also be twisted, shaped or rolled during processing. The finest green teas are shaped and fried in a wok with just a few hundred grams at a time!
Green tea can be made from any of the flushes. The most expensive ones are often from the first flush. In areas of China that produce white tea (of the first flush), the second flush is used while the third flush is most common in India.
There is a wide range of flavors and appearances with green tea. In China alone, there are hundreds of different types.
Yellow tea is made very similarly to green tea, but does not have the same vegetal flavor. The difference is mainly in a slower drying phase that yellow tea gets. After the leaves have been steamed and become moist, the leaves are left to dry. Different provinces use different methods of drying, but often it happens between paper. This process gives it a clearer and smoother taste than green tea.
Yellow tea is only produced in China (Yunnan, Hunan, Anhui and Sichuan) in very small quantities.
"Yellow tea" was, without comparison, formerly an expression for the tea the peasants gave to the emperor as tribute every year.
Oolong tea is semi-oxidized. This happens by pounding the leaves, preferably in a bamboo drum, and roasting in repetitive exercises over a period of time until the desired oxidation is achieved. Oxidation of oolong can vary from 10 to 90%. The production of oolong is complicated and the tea is able to hold a complexity of flavor and aroma beyond what white, green or yellow tea can.
Some oolong teas are repeatedly rolled and roasted to shape the leaf. Some are processed by machine, others are by hand, this brings the moisture from the inside to the outside of the leaf.
Black tea is fully oxidized. That is, the oxidation process is allowed to stop on its own. After oxidation, the tea is dried by roasting. It is oxidation that makes the tea leaves dark.
Black tea has a strong, often earthy taste and is the most common type drunk in the Western world. Most people prefer to drink black tea with milk, but high quality teas such as Assam, Keemun and Darjeeling are also lovely on their own. A common misconception is that black tea has more caffeine than other types of tea, but it is the cultivar of the tea plant that determines the caffeine content and it is practically kept constant after harvesting the leaves.
Black tea is the most common variety we know in Norway and in the West. Mostly it is black tea, of poor quality, we find in tea bags and tea that has been flavored.
What sets puerh apart from other types of tea is that it is compressed and given the opportunity to develop -or added- a bacterial culture (such as wine and cheese) and ferments for a specific period. This makes it suitable for storage and many teas get better with age, but proper storage is very important. The tea is packed together in the form of a ball, plate or cake. For brewing, a piece of the desired size must be cut off.
The production of pu-erh is surrounded by music and some types can be stored as fine wine. It is common for pu-erh to be 3 to 10 years old, but there are also younger and much older versions. The oldest are dated back to the Qing dynasty in the 16th-18th centuries.
Puerh tea has a very complex, strong and earthy taste.