Does tea ferment?

In this brief guide, we are going to answer the question “does tea ferment” with an in-depth analysis of whether or not tea ferments. Moreover, we are going to discuss the changes brought about by fermentation and the classification of tea on the basis of fermentation.

So without much ado, let’s dive in and figure out more about it.

Does tea ferment?

Yes, tea does ferment and the process of fermentation brings about many changes in the chemistry or chemical composition of tea leaves. Molds are the species that are chiefly responsible for bringing about the process of fermentation. 

There is a little contradiction regarding the chief species that are responsible for the fermentation of tea. 

Some studies point out that Aspergillus Niger is the one that is the principal organism that brings about the changes in tea leaves by the process of fermentation while other studies suggest that Aspergillus luchuensis is the primary agent responsible for fermentation.

What are the changes brought about by fermentation in tea?

The fermentation of tea leaves changes their overall chemistry. so what the process of fermentation does is that it changes the organoleptic characteristics of the tea that is made by using such leaves. 

it is worth mentioning that organoleptic characteristics or organoleptic properties are the ones that are perceived by using the five senses of touch, taste, sight, smell, and taste. 

So fermentation influences the smell of the tea and gives the tea its characteristic soothing aroma. 

The process of fermentation also changes the taste of the tea and improves it by diminishing astringency and sharpness while improving the mouthfeel and persistent flavor of the tea. 

The microorganisms may likewise create metabolites with wellbeing benefits, thereby responsible for the benefits that are associated with tea.

Classification of tea on basis of fermentation

Tea is categorized into four categories based on the degree to which they are fermented.

  1. Non and light-fermented
  2. Semi-fermented
  3. Fully-fermented
  4. Post-fermented

Non and light-fermented tea

Non or light-fermented teas are the ones that have an oxidation status of only 10%. These teas include green tea, yellow tea, and Jasmine scented green tea. 

To inhibit the process of fermentation in these tea variants, the leaves of tea are pre-heated via steaming or roasting, and this pre-heating halts the process of fermentation in them. 

Non and lightly fermented teas mostly have their color between yellow to green, a refreshing smell and they are famous for their benefits.

Semi-fermented tea

Semi fermented teas are the ones that are fermented between 10% to 80% and are further categorized as light (10%-20%), medium (20%-50%), and heavy (50%-80%).

When semi-fermented tea is brewed they yield a brewed tea having a soothing, fragrant aroma and have their color between slight yellow and brown.

Pouchong tea, ding dong oolong tea, and red oolong tea are some of the examples of semi-fermented teas.

Fully fermented tea

Black tea is a fully fermented tea and it is worth mentioning that the fully fermented tea has a strong aroma, taste, and color. 

What the process of fermentation dies is that it changes the insoluble compounds present in the formulation of tea leaves in the soluble ones that can easily get dissolved in water. 

These compounds are the ones that are responsible for the flavor, color, and aroma of the tea.

Post fermented tea

Post fermented teas are the ones that are allowed to ferment, then the process of fermentation is stopped for some time, and afterward, they are again allowed to ferment. Pu-Erh tea is an example of post-fermented tea.

You can read how to make Kombucha tea here.

Tips to store tea properly

You should always store dry tea in an air-tight container or jar and store it in a cool, dry, and dark corner of your pantry or kitchen cabinet to preserve its freshness for a long time. You should never store your dry tea in a humid environment as humidity is the enemy of the delicate flavors of tea and it can even spoil your tea (if tea is stored for too long in a humid environment and that too uncovered).

Tea can pick up smells and that is another reason why we advised you to store your tea in an air-tight container. 

UV radiations present in the sunlight can also mess up the delicate flavors of tea, therefore it is recommended that once you open your tea pack, store the rest of the tea in a tinted or colored air-tight container. 

The reason behind using a tinted or colored container is that the sunlight won’t be able to penetrate it, thereby the quality of tea will be preserved for a long time.

Another thing that you should always remember is to never use a wet spoon to scoop out tea. Moreover, you should close the lid of the container in which you stored tea as soon as you are done scooping out the tea that you needed.


In this brief guide, we answered the question “does tea ferment” with an in-depth analysis of whether or not tea ferments. Moreover, we discussed the changes brought about by fermentation and the classification of tea on the basis of fermentation.



Mahnoor Asghar is a Clinical Nutritionist with a bachelor's degree in Nutrition and Dietetics. She is compassionate and dedicated to playing her part in the well-being of the masses. She wants to play a fruitful role in creating nutrition and health-related awareness among the general public. Additionally, she has a keen eye for detail and loves to create content related to food, nutrition, health, and wellness.

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