Fundamentals of Green Tea
Have you ever walked into a restaurant and ordered a green tea by name? It’s pretty uncommon to have more choices than just “green or black”, but inside the category of green tea there is a vast spectrum of distinct teas to choose from. Fresh, fragrant, and cleansing, a good green tea offers a full sensory experience reminiscent of where it’s grown. Green tea can range from strongly savory, to delicately floral, to rich and fruity and any combination thereof. Green tea production encompasses four basic elements, and it is from these fundamentals that the endless variations arise.
Green tea has three steps from after harvesting to packaging. These are stopping fermentation, rolling, and drying. Fermentation here means that the enzymes in the tea leaves react with oxygen to begin breaking down some compounds and building new ones. This process is necessary to create black tea, but is undesirable in green tea, since it will interfere with the tea’s freshness.
To stop the enzymes from working, the leaves must be sufficiently heated. There are three different ways to heat the leaves effectively and these create the four different styles of green tea.
Steamed: The oldest method, hot steam is applied to the leaves to stop fermentation. This gives the most fresh appearance and taste, usually fairly grassy, and sweet. Although there are some Chinese green teas that use this style, it is most commonly used in Japan where familiar Sencha, Gyokuro, and Bancha teas are steamed.
Pan Fired: Pan fired teas use large hot woks to directly apply heat to the leaves. They have a distinct zip to them that is said to contain more energy and are associated with floral aromas. The most famous examples of these teas are Dragon Well and Bi Luo Chun.
Hot Air: The newest of the four methods, hot air can be used to stop fermentation. In this style, a long rotating cylinder is heated and then the leaves tumble inside, essentially baking. Mao Feng is made in this style, and it is from this heating that fruity and chestnut notes are fully evoked.
Sun dried: While sun dried leaves are a distinct style, it is only the final drying stage that is actually done in the sun. Usually sun dried teas stop fermentation by pan-firing, although there are exceptions. Sun drying keeps the most terroir in the leave as it soaks in the essence of the mountain where it was produced. This drying can be gentle enough to allow teas to age. For this reason, raw pu-er can be considered the most iconic of this style, though more often put in its own category.
Rolling is straightforward: the leaves are rolled either by machine or hand. This is to break down the cell walls enough to have some compounds interact with the air (increasing flavor and aroma) and also allows it to be shaped.
A fact that may surprise some green tea drinkers is that the season of harvest matters a good deal to the final product. The best season is Spring, because the leaves have more energy and tasty compounds. These teas are the most flavorful, the most delicate, and the most sweet. The next best season is fall. Fall harvests are less sweet but have a stronger fragrance than teas from spring.
Summer is rarely a good season to harvest tea, because it is too close to the spring harvest. This will result in tea that is less flavorful, more bitter and astringent, and causes too much stress on the tea plant to remain healthy for a long time. Respectful gardeners allow their plants to rest during the summer season and do not over pick the leaves.
Region and Variety:
Although all tea comes from the Camellia Sinensis plant, there are many different cultivated varieties. A single named tea such as Dragon Well may be made from one of several different varieties of tea plant. Usually the tea name comes from a geographic area and processing style, but there are often original plant varieties associated with each type of famous tea.
These two elements go together because of the evolution of tea. People experimented with local teas to find the process that worked best for that variety grown in that region. Famous teas spread due to their success, but transplanting a certain variety to a new climate is not always successful, nor is using a particular process with a different variety of tea.
Complicating everything is that much of the tea on the market labeled as famous teas are actually lower quality and grown in other regions. While lots of experience allows seasoned tea lovers to tell the difference, newer tea drinkers should find someone they trust to guide them in their tea adventures so they can develop the structure of what the names should taste and smell like.
Green tea is the most fickle type of tea to brew well. Boiling water will burn the leaves and some compounds, resulting in very bitter tea that tastes unpleasantly cooked. The highest temperature for good green tea is usually 185 F, but for more finely milled or for more tender tea, lower temperatures produce better results.
To more conveniently reach the proper temperature for green tea, you can bring water to a boil and then pour into another cup or bowl before pouring it again onto the tea.
Knowing these fundamentals allows you to not only realize what you like in green tea, but also to help you choose those types more easily. Knowledge gives you the power to interact with your local tea shop and ask them questions about location and quality, season and method. Happy steeping!