Do you ever wonder how tea is made? What process involves that would turn fresh leaves into dried loose leaves? Are there different processes being used that contribute to the distinct characteristics that separate green, Oolong, and black tea? In this article, you’ll learn how each of them is processed from fresh leaves to final packaging.

Low Oxidization High Catechins

Let’s start with the most widely available black tea and increasingly popular green tea. Green tea does not go through the withering process, but instead straight to fixation, leaving the leaves no chance for oxidization and thus able to preserve a much higher level of catechins, a type of antioxidant. Additionally, black tea requires fermentation that further sets off chemical substance to react, turning the color of leaves from green to red.

Tea Processing: Black vs Green

Even different processes are used to produce grade-level and non-grade-level of black tea. The key difference between these two grades is whether the leaves are kept in whole or being shredded. Screening is absolutely required and normally a second twist rolling is needed to ensure its consistent quality. On the contrary, inferior leaves typically go through only one-time twist rolling since they are meant to be shredded later and often packaged into bags so are not easily for naked eyes to discern. Therefore, tea makers do not bother to screen them in order to save cost.

• Green tea (0% oxidization): harvesting –> fresh leaves–> manual or mechanical fixation–> twist rolling–> drying–> packaging
• Grade-level black tea (100% oxidization): harvesting –> fresh leaves–> indoor withering–> first twist rolling–> screening–> second twist rolling–> drying–> fermentation–> packaging
• Non-grade-level black tea (100% oxidization): harvesting –> fresh leaves–> indoor withering–> twist rolling–> shredding –> drying–> fermentation–> packaging

Taiwan Oolong Tea

In contrast, Oolong has the oxidization levels that come between green tea and black tea; therefore, it’s not surprising that making Oolong involves processes that can be found in both black and green tea. For example, indoor withering used in black tea and fixation in green tea are both used in Oolong. This enables the leaves to oxidize at various degrees, but also stops the leaves from continuing to oxidize fully at the timeframe planned by tea makers.

• Pouchong Oolong ( 8-18% oxidization): harvesting –> fresh leaves–> sun withering–> indoor withering (8-18% oxidized)–> manual or mechanical fixation–> twist rolling–> drying–> packaging
• Alishan/Milk/Dongding Oolong ( 20-45% oxidization): harvesting –> fresh leaves–> sun withering–> indoor withering (20-45% oxidized)–> manual or mechanical fixation–> ball rolling–> first drying–> cloth ball rolling–> second drying–> packaging
• Oriental Beauty Oolong ( 50-70% oxidization): harvesting –> fresh leaves–> sun withering–> indoor withering (50-70% oxidized)–> manual or mechanical fixation–> softening–> twist rolling–> drying–> packaging

Across all Taiwan Oolongs, sun withering is applied. But compared to twisted shaped Oolong such as Pouchong and Bai Hao, balls or pellet shaped Oolongs such as Alishan, Jin Xuan, Dongding and Tieguanyin, will go through rolling and drying twice rather than one.

I hope you would have a fresh perspective next time when you look or shop for different types of tea, that it does require much more work and processes than you may have assumed to get a tea from a farm to a market.