What is the difference of green and black tea?
Earlier, we talked about what makes tea tea, but what is the difference of white tea and black tea?
I’ve been contemplating how to explain this for a while and the analogy I keep coming back to is similar to distinguishing countries and continents. There are eight continents on planet earth, and most people agree there are six main categories of tea: white, green, yellow, oolong, black, and dark (which includes pu’er).
Much like how North America and South America are distinguished by the geo-political border of Panama and Colombia, categories of tea have their own borders which are determined by oxidation levels.
Oxi-whaaa?
Oxidation is the chemical process that happens when you bite into an apple; leave it out and it starts turning brown.
The degree to which a tea leaf is oxidized, is the principal factor determining what category of tea the finished leaf will belong to. Here is a handy cheat sheet:
green tea (un-oxidized)
white tea (minimally oxidized)
oolong tea (partially oxidized)
black tea (almost fully oxidized)
pu’er tea, a sub-set of “dark teas” are distinguished by post-processing
yellow tea (a fairly rare category of tea) is a post-processed green tea that is allowed to further oxidize in meticulous way.
Tea processing is basically the artful manipulation of heat and moisture to optimally control oxidation.
Oxidation vs. Fermentation
It is important to make a quick aside distinguishing a frequent mix-up in tea education between oxidation and fermentation. These are two totally different scientifically defined chemical processes and should not be used inter-changeably.
As you see in the bullet list above, only two categories of tea undergo the chemical process of fermentation: some dark and all yellow teas. To repeat: the most important chemical process for tea making and distinguishing tea categories is: oxidation.
Continents : Countries:: Oxidation : Terroir and Cultivars
Within geographical continents, there are hundreds of countries which together make up the continent. Similarly, within each category of tea, there are hundreds of specific teas (for instance, hundreds of different green teas in China alone) that make-up the broad category of green tea.
To continue with my continent and country analogy, oxidation level is the border that divides continents/categories of tea. Terroir and tea plant cultivar are the properties that distinguish countries from each other within a continent/types of tea within a category of tea.
Just like Korea and Japan are both Asian countries but distinctive, unique, and separate countries, Iron Goddess of Mercy oolong tea and Phoenix Honey Orchid oolong tea are both oolong teas but have distinctive, unique, and separate properties that differentiate them from each other.
So while countries within the same continent may vary specifically in linguistic, cultural, and historical differences, the main features that distinguish tea within the same category from each other are terroir and plant cultivar.
Terroir? Plant cultivar? Don’t worry! We’ve got you covered…I break these down for you here.