Green tea is not always green. You may come across green tea leaves that seem brownish, white or yellow. The tea you make from these leaves can be anywhere from a pale white color to a dark brown.
If green tea is called green tea, why is it not green? And why does this tea type have all these different colors? In this post, I want to go into detail about the color found in green tea.
SHORT ANSWER – Why Green Tea Sometimes Is Not Green
The color of green tea is green because of compounds like Chlorophyll. The infusion of green tea is not necessarily green and most Chinese green teas will yield a yellow infusion. The color of green tea will change over time through oxidation, decomposition and microbial activity.
So processes are happening within the tea leaves and the beverage that change the color of the tea. Now I want to go into detail for each of the possible colors to explain how these come to be and if you should be concerned.
Why Is Green Tea Called Green Tea?
The categories that we commonly divide tea into are based on the color of the tea leaves themselves and not necessarily the resulting brewed tea. Green tea production takes care not to oxidize the tea leaves, which keeps them green and fresh.
Green tea leaves are most commonly green but can have yellow, white and darker colors like brown and red in there, too. The resulting brew of Chinese green tea is often anywhere between a pale yellow and a brownish-yellow.
A truly green brew is something you get with many Japanese green teas. Matcha is most well known for the green color but the tea technically contains the tea leaves themselves. The brew of Fukamushi and Gyokure often have a pale green color.
So green tea is associated with green color because of the tea leaves mostly nowadays. The Japanese way of processing green tea has been common in ancient China too, though. The origin of the name could come from the brew itself but this does not make sense nowadays.
Why Is Green Tea Green
The green color of green tea comes from the same molecule that makes the leaves of any plant green. It’s Chlorophyll, which are pigments found in algae and plants. (Source)
Chlorophyll is needed to do photosynthesis and therefore is necessary to keep the plant alive. Chlorophyll is inside the leaves and the tea leaves will stay green as long as these molecules are not decomposed or destroyed.
With black tea, oolong tea, cooked Pu Erh tea, and aged raw Pu Erh tea you can tell that aging and oxidation will decrease the green color of tea. The same is true for green tea.
Over time the green color will disappear naturally and depending on the processing of the tea leaves, the color of the tea leaves and the resulting brew can vary.
Why Is Japanese Tea Green
As stated, Japanese green tea is the tea that is greenest in color. A few things are special about the production of Japanese green tea that play into this.
The first and primary reason that is true for almost all Japanese green teas is the steaming. Japanese green teas are steamed with hot water to kill the enzymes and microbial activities within the leaves. This will keep the green tea fresh and green.
Chinese green tea is roasted, which introduces heat directly to the tea leaves and creates steam by doing so. This direct heat will partially degrade compounds in the tea. Just like food in a frying pan, the leaves will get brown and the Chlorophyll is partially destroyed.
Furthermore, Japanese tea farmers often shade the tea plants days or weeks before harvesting the tea leaves. As the plant gets less sunshine, the tea plant will produce more Chlorophyll to stay alive and be able to grow.
This step in Japanese tea production is an additional effort not everyone wants to put in. You can see the difference between shaded and regular tea with cheap and quality Matcha.
High-quality Matcha will have an intense green color while the cheaper unshaded Matcha will have a yellow color and be far more bitter in taste. I recommend tasting both variants at some point to taste the difference there.
How Is Green Tea Different From Black Tea?
What makes black tea black and green tea green? The reason for green tea being green has been stated above. But what makes black tea black and where does the green color go?
Black tea is fully oxidized tea. The oxidation process is what destroys the Chlorophyll and through that the green color. If you look at oolong teas of different oxidation levels you will notice lightly oxidized oolong still has color and taste of green tea.
Medium and highly oxidized oolong tea will be more like a proper black tea. Additionally, some teas are roasted as part of the processing. This is most common with oolong teas. The introduced heat will also destroy the green color within the tea leaves.
What Makes And Changes Color Of Tea
Green tea can have many colors. Green, yellow, white, brown, red or black are all colors found in tea leaves in the same way you find them with tree leaves in autumn. There is a reason for every color and I want to go more into detail here.
Oxidation And Tea Color
Oxidation reactions are very common. With tea, oxidation is associated with black tea and oolong tea.
This reaction type is inevitable and happened to every tea you have ever had. Oxidation of green tea will, over time, slowly degrade the Chlorophyll contents of the tea. (Source)
This will result in the slow disappearance of the green color. With some types of tea, this process is desired but with green tea, we do not want this to happen.
The oxidation of green tea will result in brown, red and black colors. Green tea should be stored cool, dark and ideally under nitrogen or in vacuum packaging to be kept from oxidizing.
If you have green tea that is a year or two old, you will notice the diminished green color already. We all have that old green tea that we do not touch anymore because it does no longer taste fresh and vibrant, right?
Green Tea Color Change Through Heat
Heat has a major impact on the Chlorophyll content of the tea leaves. I have mentioned earlier that Japanese green teas are steamed and that the steaming process will keep the leaves greener than the pan-frying or roasting processes common in China. But why is that?
The roasting process introduces heat through contact with the metal surface of the wok. Where the tea leaves touch the metal, the leaves are heated to very high temperatures and will burn.
As this process goes on, more and more of the tea leaves will turn brown and black through a process essentially in the same way as fried food will turn brown through direct heating.
The steaming method limits the temperature to the boiling temperature of water. This is enough to kill the enzymes in the tea leaves, but will not burn the tea. The resulting tea is not as sweet or complex but is able to develop unique grassy and vegetal flavors.
Color Change Through Natural Decay
The two processes previously mentioned are the main processes responsible for the decay of Chlorophyll and the green color of green tea. Additionally, the green color will diminish over time through natural processes.
These processes can often include microbial activity inside the tea leaves. With raw Pu Erh tea, this is commonly seen and desired. But organic compounds like Chlorophyll will also naturally decay over time.
The disappearance of the green color is faster when the tea is stored warm, as higher temperatures allow for faster decay. You can store green tea in the refrigerator to keep it fresh.
Light is another major factor in the natural decay process, as it is able to destroy the molecules responsible for color and taste. Remember to keep your tea safe from light and especially UV-light!
Why Tea Turns Black With Honey
You may have tried drinking your green tea with natural sweeteners before. If you tried to add honey to your green tea, you may have noticed the tea to turn into a dark brown color, maybe even black?
With some brands of honey green tea will turn opaque grey, brown or even black. The reason for this could be oxidizing agents present in the honey that rapidly oxidize the green tea. The green tea will then look the same as if you would have left it out overnight.
Why Is My Green Tea White?
Green tea leaves will be partially white or overgrown by white hairs naturally. The buds of the tea plants have very noticeable white hairs that can get quite long.
Other than this, light green or light yellow colors are common with tea leaves that have not been oxidized such as green tea, yellow tea, and white tea. All of these teas are far less oxidized than dark oolong tea or black tea.
Depending on the tea you have, the resulting brew can be very pale in color. Young teas produced in the same year that have been delicately handled are more likely to have a pale infusion.
Generally, an infusion made from intact loose leaves are lighter in color and less opaque than those from broken leaves and tea bags. The broken leaves will have more surface area and be able to let more colored compounds dissolve into the tea.
Why Is My Green Tea Yellow?
The tea leaves of green tea can have a yellow hue to them, as the color varies depending on the Chlorophyll content of the leaves and the time of harvest.
Chinese green tea most commonly yields a yellow brew. Through the pan-frying or roasting processes in green tea production, green pigments in the tea are partially destroyed.
The steaming process in the production of Japanese green tea allows the resulting brew to be much more green and vibrant in color as the pigments remain in the tea leaves.
Using high water temperatures when brewing green tea, you are more likely to get a yellow infusion. The yellow color comes from compounds that are more easily dissolved at high temperatures in the same way that bitter compounds are dissolved.
Why Does Green Tea Look Brown?
You may have been asking yourself why some green tea is brown. The most likely reason for this has to to with the processing done during production, the brewing methods you use.
First I want to clarify that broken tea leaves and tea bags are far more common to yield a brew that is darker in color such as yellow or brown. This is due to oxidation processes happening to the broken tea leaves which makes the green tea less green.
If you oversteep your tea, you may dissolve pigments that are darker in color and through that turn your tea brown in color. You could try using lower temperature water and check if that is the case.
Other tea types that yield a brown liquid are black tea and darker oolong teas. This is due to oxidation processes that change the composition of the tea.
Chlorophyll, which is the main pigment responsible for the green color of green tea, will be destroyed through oxidation. Furthermore, oxidation processes tend to darken the tea leaves and the resulting tea further.
Why Green Tea Turns Brown When it Sits
Green tea will turn darker and darker over time until it becomes very dark brown or black. Leaving out your tea allows the molecules that have been dissolved in the water to oxidize.
Before brewing the tea, the tea leaves have been protecting the molecules and the surroundings did not allow for the oxygen present in the air to fully oxidize the tea.
When the tea has been made and left out overnight, the oxygen will have much better chances. The dissolved molecules are much more susceptible to oxidation and will turn dark overnight because of this. After one or two days, the tea will be completely dark and opaque.
Why Is My Green Tea Red?
Red color is rather uncommon with green tea. This color is also predominantly created through oxidation and heating processes and is most often found in oolong tea.
If the tea leaves of your green tea have red parts, this is most likely due to some mistakes made during production. Mistakes may be the wrong word to use because the outcome could be desired by the producer.
When roasting tea through pan-frying or directly of fire or hot coals, the composition will change as molecules are destroyed and recombined in the heat. Some of these processes yield compounds that are red in color.
Why Green Tea Turns Red
If green tea you have brewed turned red over time, you do most likely have the same case as described above under the headline Why Green Tea Turns Brown When It Sits. I will give a quick summary of that here.
When brewed tea is left out in the open air, the tea will oxidize. The oxidation process is responsible for the light and pale colors turning dark and brown or even completely black. You will almost always see your tea turning opaque, too.
This process will occur very fast with some teas and you may notice your tea turning slightly brown only a few minutes after pouring from a teapot into a glass or a cup.
If your tea turns into a dark red color this is most likely the same color as black tea, a fully oxidized tea variety would have. Essentially, your green tea has turned black.
There’s a lot more to learn about tea! If you are looking for a good place to start, I highly recommend the book Tea: History, Terroirs, Varieties. You can check its current price on Amazon here.