Different Types of Tea

A Handful of Tea Leaves

A Handful of Tea Leaves

For the casual observer it is safe to assume that all types of tea are produced from a common source material, the leaves of the camellia sinensis plant family – although there are some minor variations to this if my understanding of current taxonomy beliefs is correct. The differences experienced between tea types being due to the either the standard of leaf harvesting or processing methods.

Teas are most often classified into 6 broad types:  Green, Black, Oolong, Yellow and Dark.  Probably the most significant difference between types is the degree to which leaves are allowed to oxidise during processing (as this is where the greatest chemical changes occur), but it does not tell the whole story.  In simple ‘elevator pitch’ terms (but not necessarily technically correct) green tea is un-oxidised, oolong tea is semi-oxidised and black tea is fully oxidised.  White, dark and yellow teas can be regarded as variations or extensions of these three types.

There are some who have very fixed views on whether individual teas belong to a particular category type or not often based on their own prejudice or expectations.  There are most definitely overlaps at the boundaries between each type.  Personally, I see it more as a guide to what you might expect and have never come across any prescriptive rules stating that a particular tea must be processed in a particular way.  I look at it in the same way as a movie being assigned to a specific genre.  If you went to see an Action movie and it had a touch of Romance then who cares.  But if you went to see a Sci-Fi and it turned out to be a Musical then something has gone very wrong.   I believe it is best to remain open-minded provided there is not an intention to misrepresent or mislead.  A tea should be judged on your overall experience rather than in comparison to a checklist of features.

Tea Leaf Styles

Tea Leaf Styles

Before continuing we will pause to consider some of the terminology used in tea circles, specifically in relation to ‘oxidation’.  Oxidation is a chemical reaction that occurs when harvested leaves come into contact with oxygen.  The more of the leaf structure that is exposed to oxygen the greater the degree of oxidation.  Oxidation can be prevented or stopped by heating the leaves at the desired time; a process known as kill-green, firing or denaturing.  In the early days of tea processing it was believed that this process was, in fact, fermentation and even now the words ‘oxidation’ and ‘fermentation’ are used interchangeably. To add more confusion is the fact that a more accurate description of the process should be ‘enzymatic browning’ rather than oxidation but as oxidation is the most commonly understood I will continue to use it here.

A final complexity is with dark teas which are typically referred to as post-fermented.  For these teas further chemical changes take place at the end of processing as a result of microbial action.  While fermented or post-fermented teas are the generally accepted ways of describing such teas it would be more accurate to describe it as microbial ripening

We will consider the detail and intricacies of Tea Processing at another time and for now content ourselves with a very brief introduction and overview to each type:

Green Tea (genre: Drama) – a short physical wither after which leaves are fired within a few hours of harvesting to deactivate the enzymes that cause oxidation and the chemical changes that this produces.  Firing can take the form of steaming, baking or frying.   The leaves are then generally rolled and dried but maintain much of their green colour. Tea flavours are typically grassy, vegetal or floral.

Black Tea (genre: Action) – subject to a prolonged controlled physical and chemical wither prior to a hard rolling (maceration) that breaks down the leaf cell walls to facilitate oxidation.  Once oxidation is complete the tea is dried, graded and sorted.  Black teas are often  brisk, full bodied with flavours tending typically towards malty and chocolate.  In China, black tea is referred to as red tea which is a better approximation to the colour of the brewed tea.

Oolong Tea (genre: Adventure) – undergo physical and chemical withering before being shaken/ bruised at the edges to promote oxidation.  The degree of oxidation in Oolongs can vary greatly and are typically quoted as being between 20% – 80%, which is often an estimate in any case.  The complexity and variety of flavours in Oolongs is vast and is further developed by the practice of roasting or ageing the finished tea.

White Tea (genre: Romance) – mainly just withered and dried although it is sometimes lightly rolled for shape.  Usually described as minimally processed, this is only true in terms of process steps rather than the time and degree of attention required.  Oxidation occurs during extended wither but is controlled through drying rather than firing.  Frequently but not always made from leaf buds only while the inclusion of young leaves delivers stronger flavour.

Yellow Tea (genre Sci-Fi) – a variation of green tea, yellow tea undergoes an additional step of moist heaping or smothering under cover after firing and before rolling.  The resulting tea is more mellow and without the grassy aroma of green tea.  It is the least common of tea types.

Dark Tea (genre: Epic) – aka post-fermented tea of which the most famous is Pu’erh tea.  Dark tea will usually start life as a simple green-like tea but allowed to ferment (microbial ripening) as a post processing activity.  A more recent development has seen accelerated ripening employed by heaping fired leaves under covers to promote microbe activity.  This is referred to as ‘cooked’ Pu’erh while the more traditional method (i.e. without accelerated ripening) is known as ‘raw’ Pu’erh.  Earthy and woody flavours are typically associated with post-fermented teas.

Flavoured Tea (genre: Musical) – not really a type of tea but an increasing trend is flavoured teas.  Tea leaves have a great capacity for absorbing flavour and there are a wide range of available, from the more traditional floral scents (e.g. jasmine) to more exotic and contemporary flavours.  Many purists turn up their noses at scented teas but they can be delightful.  The majority of modern flavoured teas, however, are artificially scented.

Blending Tea With Flowers

Blending Tea With Flowers

Here in Vietnam all types of tea are produced albeit in different quantities and qualities.  The exception is any yellow tea as described above although you will come across those who say they are making trà vàng (literally yellow tea), particularly in the wild tea growing areas.  This, though, is a very basic green tea (no smothering involved) that frequently goes across the border to China for further processing as dark tea.

Oolong tea production is a more recent phenomenon in Vietnam often in collaboration with Taiwanese businesses while dark tea production has long been undertaken but is having something of a renaissance due to increased worldwide interest.

Jasmine and lotus teas from Vietnam have become quite well known in overseas markets.

What Is Tea? The Basics.

Tea Bud and Leaves

Tea Bud and Leaves

At the most basic level the answer to the question “What is Tea?” is a simple one.  It is leaves harvested from a specific type of bush where most of the water has been removed without anything else being added.  That the skills and techniques in achieving this are so many and varied are what makes it such a fascinating subject and the range of teas available so many and varied.

The term tea (at least in English) also has a certain ambiguity to it and if, in the future, you were to summon your virtual assistant to “bring me some tea” the outcome could well be unpredictable.  For a start, tea is used not only to describe the dried leaves but also the drink made by steeping those leaves in water.  An added complication is that in some circumstances, say in ordering a peppermint tea, there would be no actual dried tea leaves involved – unless that is it happened to be a green tea blended with peppermint.  Many other leaves, roots and flowers are steeped in water to produce a drink and although these should more correctly be referred to as tisanes, common usage is most likely to describe these as tea.

If you were to subscribe to a news feed with the keyword of ‘tea’ then the most popular topic coming your way would concern places near you where you might find an attractive afternoon tea.  Originally a British invention this has now made its way around the world and although tea is usually served at these events the main attractions are the variety of cakes and sandwiches that will accompany it.  Even more confusing is that in some parts of the UK people refer to their evening meal as tea (or high tea) which may include a hot meal, pudding, bread and butter but not necessarily any tea.  I trust that has cleared things up.

Wild Tea Tree

Wild Tea Tree

In the very long many thousand year history of tea and the way that we now usually make tea (i.e. steeping dried leaves in water) is a relative recent innovation (only in the last 600 years or so).  If this were trendy, like coffee, we might well call this third wave.  Go right back to the very early origins of tea as a folk medicine and the leaves would have been used fresh from the tree and indeed some people still make tea in this way today.  Drying or processing tea was a means to preserve it and transport it to distant lands.

All cultures would have used leaves, roots and flowers at one time either as herbal remedies or possibly for recreational drinking.   As an example the English botanist Nicholas Culpepper identified over 400 medicinal herbs in his 17th century publication The Complete Herbal (original published as The English Physitian in 1652 and available to download or read for free from here if you are interested).  Despite his research into the medicinal use of herbs, Culpepper died at just 37 years old.

That out of all the potential different brews tea rose to become a worldwide favourite is testament to the special properties of this remarkable leaf.  In the same way grapes became the preferred fermented fruit in the making of wine (due to the ideal balance of sugar, acidity, water content, skin surface etc.) tea claimed the throne in the non-alcoholic world as a result of the incredible complexity and uniqueness of its leaf content.  A tea leaf contains many thousands of chemical compounds but more about this another time.  Differences in processing techniques and sequences cause these compounds to interact in ways that result in the different styles and types of tea now available.

We now know that all types of tea (green, black, white, oolong, yellow, dark) are made from the leaves of the same plant.  It would be possible to make any style of tea from any harvested leaves although the results and quality might well vary.

Farmed Tea

Farmed Tea

To keep things simple, for now, it would be ‘almost’ correct to say that all tea is made from the same plant species: Camellia sinensis and that there are two main varieties used for the majority of commercial tea production.  These are Camellia sinensis var sinensis and Camellia sinensis var assamica – although other varieties (and other Camellia species) are also put forward as sources of tea leaves.  The taxonomy of plants isn’t as clear cut (or scientific) as one might think and much of the classification is based on observation rather than anything else.  Much more knowledgeable people than me have argued this topic for many years and we shall probably come back to it in more detail at another time.

As tea production developed into a huge industry, researchers and planters developed new cultivars (short for cultivated varieties) either to improve pest and disease resistance or in search of particular characteristics that would find their way into the finished tea.  Many of these cultivars would hybrids of the sinensis and assamica varieties.

Tea was originally a wild plant native to parts of Asia.  To quote from the Royal Botanical Gardens, Kew on the plants geographical distribution:

The origin of tea is not clear. Camellia sinensis var. sinensis is probably native to western Yunnan, while C. sinensis var. assamica is native to the warmer parts of Assam (India), Burma, Thailand, Laos, Cambodia, Vietnam and southern China. ‘Wild’ tea plants can be found growing in forests, but these may be relics of past cultivation.

Left to own devices the tea plant will grow into a small tree of 10 metres or taller.  In a farm environment it is typically kept pruned back as a shrub with a height of around one metre to aid harvesting.

If the tea plant was indigenous to a fairly broad geographic area, one in which political boundaries have shifted frequently over the time, the development of tea as a recreational beverage and as an industry rests entirely in Chinese culture.  Although there is some evidence of tea cultivation as far back as 6,000 years ago the drying and shipping of tea most likely dates back to the 4th or 5th centuries.  A sure sign that it was a significant industry is that taxes on it were introduced in China by the end of the 9th century.

Today commercial tea production has spread to over 40 countries and totalled 5,300 metric tonnes by 2015.

Wild Tea Trees of Vietnam

It is generally accepted that the tea plant is native to parts of China, Assam (India), Myanmar (Burma), Thailand, Laos, Cambodia and Vietnam. In a number of these countries, including Vietnam, wild tea plants can still be found growing but are most likely relics of past cultivation rather than truly wild.

Ancient Tree Suoi Giang

In Vietnam it is the mountainous area in the north of the country where wild tea trees can be found, usually growing in mixed forests on high mountain slopes. Significant wild tea areas exist in Dien Bien, Lai Chau, Lao Cai, Yen Bai and Ha Giang provinces reflecting the spread of one-time nomadic ethnic groups (particularly the H’Mong and Dao ethnic groups) whose habitation in these parts pre-dates any current geographic boundaries. It is believed that families carrying tea seeds with them as they moved from place to place is responsible for much of the current distribution.

There is also a story that an expansion of wild tea planting in the second half of the 19 th century was prompted by bags of tea being accepted as settlement of tax demands by the colonial French government. The alternative was to spend time working in government run factories.

Many extravagant claims are made about the age of tea trees. There are some in Vietnam that are said to have been dated to 800 years old but a best guess is that the majority are somewhere in the range of 80 to 150 years old. Differences in altitude, aspect, soil and climate means that trees grow at different rates making comparison difficult. Without human intervention trees may reach 4 or 5 metres in height. As the trees seed themselves you can also find younger trees but these take many years to reach maturity.

In Vietnam you will often found wild trees referred to as shan tuyet which translates literally to snow mountain. In theory a shan tuyet tea should mean that it is produced from old wild tree leaves but this is not always the case. It is also no guarantee of quality. In recent years, as the popularity of wild teas has grown (particularly demand from China), new plantings of wild trees have been made but at far greater density than the truly old trees. The older trees are typically found in mixed bio-diverse environments – often very remote, deep into the forest and only accessible on foot. All of our own teas are made with leaves harvested from old trees.

The climate in the far north of Vietnam is sub-tropical but at altitudes of 1300 metres and above there is more variation in temperature. The mountains are often shrouded in mists causing trees to grow more slowly. Even so the trees can grow up to and beyond 5 metres making it necessary to climb into the trees to harvest the leaves.

Climbing Tea Tree

Wild trees are typically on land cared for by ethnic minority families who will also take responsibility for harvesting the fresh leaves (there is usually no other human intervention other than harvesting.) Families may then process the leaves themselves or sell to other families or factories for processing. With demand for leaves high there is always plenty of selling options and it remains as useful source of income.

Having good source material (leaves) only goes some way to making a great tea. The real difference comes from the skill of the tea maker. You can visit any tea district and find a range of qualities on offer from average to excellent. That is where the advantage of careful selection comes in.

Old trees with deep roots and slow growth give these wild mountain teas their special character which can be very different to farm grown equivalents. A wild tea may not have the same intensity from the first steep but it will continue to develop, have greater depth and complexity and deliver flavour for longer.

Wild teas can be an acquired taste but when you have discovered a good one there can be no going back.