What is fermented tea?
Fermented tea is a black tea that has undergone fermentation. In addition to oxidation, which is common to all black teas (the darkening of the leaves when exposed to air), a new step takes place: fermentation. This plays a significant role in defining the flavour, giving fermented tea its unique character.
How is tea fermented?
Placed in a warm, humid environment, the tea comes into contact with moulds, yeasts and bacteria. The proliferation of these micro-organisms accelerates the ageing of the tea leaves. Different techniques are used to achieve this. The first is ancestral, artisanal and traditional. It simply relies on time—a long ageing process to ferment the tea leaves, ideally in a warm, humid cellar, which provides the most favourable environment. The second method, developed in the 1970s, is more industrial. To save time, the process is accelerated, sometimes with the addition of yeasts. The leaves are moistened and placed under an airtight cover in a room with constant heat and humidity for about fifty days. The goal: deprive the tea of oxygen and accelerate the proliferation of micro-organisms.
The different names for fermented tea
In China, the birthplace of tea and the world's leading exporter, post-fermented tea is known as “black tea” or “dark tea”. It is called this because what Westerners call black tea is known as “red tea” by the Chinese. Among the various varieties of Chinese fermented tea, the most famous is Pu-Erh tea (or pu'er tea), grown in China's Yunnan province. Often mistakenly called “semi-fermented tea”, Oolong tea is not, in fact, a fermented tea. It is a semi-oxidised tea, halfway between green tea and black tea. This is why it is also referred to as blue or blue-green tea. It just goes to show that with tea, you can find (almost) every colour of the rainbow!
What does fermented tea taste like?
Fermenting tea radically transforms its flavour. Forget the astringency and bitterness often experienced with certain teas. Fermented teas boast smoother, earthier notes, paired with intense woodland undertones. For instance, Chinese fermented tea Pu Erh is renowned for transporting you to the heart of the forest, closer to ancient nature. Quite a journey!
Kombucha, a very trendy fermented drink
A trendy elixir, kombucha is not strictly speaking fermented tea. It is a fermented beverage born from the symbiosis of bacteria and yeasts. It is primarily for flavour that kombucha is made with black tea, green tea, white tea, or from herbal teas and infusions. Using already fermented tea is not a requirement at all. It is the addition of a colony of micro-organisms (known as the “kombucha mother” or SCOBY) that enables fermentation. Under the action of bacteria and yeasts, the sugar contained in the tea turns into carbon dioxide, acetic acid, and a small amount of alcohol (less than 1%). Although enjoyed for thousands of years, the kombucha drink is enjoying a comeback, like all fermented foods prized for their probiotic properties. The micro-organisms they contain are thought to be beneficial for our gut flora.
Precautions to take before drinking Kombucha
Often homemade, Kombucha is not an innocuous drink. If it is too sweet or too acidic, it can damage tooth enamel in particular. Furthermore, the bacteria contained in the beverage, if too “aggressive”, can be harmful—especially for pregnant or breastfeeding women, or for vulnerable and immunocompromised individuals. Make sure to inform yourself before giving in to the Kombucha trend.
Our tips for brewing the perfect fermented tea
Looking to discover fermented tea or introduce it to your loved ones? Here is our advice on choosing the right one and brewing it to perfection. Looking for (another) distinctive tea? Don't miss out on smoked tea, which is also very much in vogue.
How to prepare fermented tea
For a fermented Pu Erh tea, infuse for 3 to 4 minutes in simmering water at 90°C. Be careful not to boil the water, as this could damage the tea leaves. To boost its digestive benefits, you can pair fermented tea with aromatic herbs such as thyme or rosemary. Not sure which teapot to use? Take a look at our complete teapot guide.
When should you enjoy fermented tea?
The tea fermentation process has the power to reduce the caffeine level, allowing you to enjoy dark teas gently throughout the day. For most people, this low caffeine content will not interfere with sleep, although this can depend on individual sensitivity. The purported digestive benefits of fermented tea make it an ideal tea to enjoy after meals.
What are the benefits of fermented tea?
Enjoyed since the dawn of time in China, fermented tea is believed to boast digestive properties thanks to the polyphenols and theaflavins it contains. These powerful antioxidants help boost metabolism and aid digestion. Fermented tea, like other tea varieties, is also thought to have a detoxifying effect and promote weight management (alongside a varied and balanced diet).
Which fermented tea is offered by Kusmi Tea?
This is organic Pu Erh tea, a one-of-a-kind dark Chinese tea that gave its name to the city of Pu'er in Yunnan province. Pu Erh is an exceptional tea for several reasons. Firstly, its size: it comes from tea plant varieties with particularly large leaves. But above all, its distinction lies in the rarity imparted by its fermentation process. Pu Erh is a post-fermented tea, produced through a long, very gradual, natural drying process. And that's not all: Pu Erh tea also improves with age… A true treasure indeed!
Pu Erh tea, an ancient treasure
In the days of the Ancient Tea Horse Road, when famous caravans of horses and yaks journeyed across the mountains, Yunnan producers compressed Pu Erh tea into cakes (also known as “bird's nests”) or bricks to make it easier to transport to Tibet. It even served as currency. Pu Erh can be stored for several years—up to several decades for some—provided it is kept in a very humid place. It's easy to see why it is such a prized tea!
So, ready to try fermented tea?