Key Differences in Raw Material Selection and Withering for Orthodox Tea

Tea manufacturing is far more nuanced than most people realize. Two teas made from the same Camellia sinensis plant can taste worlds apart – not because of where they were grown, but because of how they were processed. Orthodox tea, known for its complex flavors and whole-leaf character, demands very specific inputs right from the beginning: the right raw material and the right degree of withering. These two foundational steps directly determine whether the final cup is worth the wait.

Why raw material selection is different for orthodox tea 🔗

Not all tea leaves are equal when it comes to orthodox manufacturing. Orthodox tea production begins in the field, where selective hand plucking is the standard practice. Pluckers focus on harvesting only the top two leaves and the bud – what the industry calls the “fine pluck.” These young shoots carry the highest concentration of the flavor compounds that define a quality orthodox tea.

The reason for this strict selectivity comes down to the rolling process that follows. In orthodox processing, leaves are never cut or torn apart – they are carefully rolled to develop a specific flavor profile. Rolling applies mechanical pressure to twist and shape whole leaves. If the leaves are too coarse, thick, or mature, they resist this twisting action, break apart unevenly, and fail to roll properly. The result is a poor-quality, inconsistent product.

This contrasts sharply with CTC (Crush, Tear, Curl) manufacture. In the CTC method, leaves pass through cylindrical rollers with sharp teeth that crush, tear, and curl the tea into tiny, hard pellets. The mechanical force involved is so aggressive that it can handle coarser, larger leaves without difficulty. In other words, CTC machines do the heavy lifting regardless of leaf grade, whereas the orthodox roller depends on the natural suppleness of fine, young leaves to do its job well.

A useful way to understand this: think of trying to roll a fresh, soft dough versus a stiff, dried-out piece – the result speaks for itself. Fine plucked leaves behave like the former; coarse leaves like the latter.

The role of leaf grade in flavor development 🔗

Orthodox tea production uses only top-quality tea leaves and buds, and in general, the larger and more intact the leaf particles, the mellower and more sophisticated the flavor. Young terminal buds and upper leaves are rich in polyphenols, amino acids, and essential oils. These compounds are what later contribute to the brightness, briskness, body, and aroma of the finished tea. Coarse leaves, by comparison, have lower concentrations of these quality-determining compounds and also contain more fibrous material that interferes with rolling.

Orthodox teas are graded into whole leaf, broken leaf, fannings, and dust categories based on the size of the leaf after processing. Even within orthodox grades, the quality of the raw material at the time of plucking determines how high up the grade scale the finished tea can reach. A well-plucked fine leaf can produce the coveted FTGFOP (Finest Tippy Golden Flowery Orange Pekoe) grade, while coarse raw material can only ever yield the lower grades regardless of how carefully the rest of the process is managed.

Withering in orthodox tea manufacture: more than just drying 🔗

Once the leaves arrive at the factory, the first major processing step is withering. This is often misunderstood as simply “drying” the leaves, but it is much more than that. Withering has two distinct dimensions – physical and chemical – and both are critical for orthodox tea quality.

The physical goal of withering is to reduce the moisture content of tea leaves to make them soft and pliable for the subsequent rolling step. Fresh plucked leaves are turgid and stiff. If those stiff leaves were sent directly to the roller, they would shatter rather than roll. Withering solves this by removing enough moisture to make the leaves flexible and workable.

The chemical changes during withering are equally important. A longer wither darkens the leaf and intensifies aromatic compounds, because many of the chemical compounds in the leaves degrade into volatile aromatic substances during this stage. Proteins break down into amino acids, soluble sugars increase, and the activity of key enzymes rises – all changes that set the stage for proper fermentation and flavor development later in the process. A leaf loses about 3-4% of its solid matter during withering, while proteins break down into amino acids and caffeine content increases.

How much moisture is removed during orthodox withering? 🔗

This is where orthodox and CTC manufacture part ways significantly. For CTC tea, a soft wither is preferred, bringing moisture content down to 60-65%. For orthodox tea, a harder wither is required, bringing moisture content down to 50-55%. This means orthodox withering removes considerably more moisture – roughly 20-25 percentage points from the leaf’s original moisture level – compared to CTC processing.

Why does orthodox tea need a harder wither? Because the orthodox roller works through compression and twisting, it needs the leaf to be more pliable and less waterlogged. If the leaves carry too much moisture into the roller, they become a wet, sticky mass rather than cleanly twisting into the desirable rolled forms. Excessive moisture also causes the leaves to clog the sifting machines in subsequent steps and can result in flat tea of low specific gravity.

Under North East Indian conditions, 70-72% wither (meaning the leaf retains that percentage of its original weight) is typically adopted for CTC, while 65-68% wither is used for orthodox manufacture – confirming that orthodox processing demands a lower final moisture level in the leaf.

In South Indian tea manufacture, withered leaves used in orthodox production generally have a moisture content of 60-65%. Regional conditions, humidity, and the flush quality at hand all influence the exact withering parameters a factory will set on any given day.

Physical and chemical withering: two types working together 🔗

Withering in a tea factory doesn’t happen in just one way. There are two types of withering: open withering and closed withering. Open withering, also called “chung” withering, admits no control over the rate of withering except by the thickness of leaf spread and the length of time. This is the natural, traditional method.

Artificial or closed withering uses temperature- and humidity-controlled troughs with mechanical fans to drive air through the leaf bed. Air is blown over the leaves in withering troughs, performing two functions: carrying heat away from the leaf and removing water vapor through the bed of green leaves. The dry bulb temperature of circulated air should not exceed 35°C, as higher temperatures can suppress the essential biochemical changes needed for quality development.

The chemical component of withering takes more time than the physical. Modern methods can reduce withering time, but they also lower the quality of the final product by limiting the time available for chemical withering. This is a key trade-off that factory managers must weigh: speed versus quality. For premium orthodox teas, a longer withering period – typically 14 to 20 hours – is preferred to allow full biochemical development in the leaf.

Understanding the degree of wither: a critical quality metric 🔗

In orthodox tea manufacture, the degree of wither is a precise, measurable parameter – not an estimate. It is defined as the percentage outturn of made tea to the withered leaf, or alternatively, the ratio of the weight of withered leaf to the weight of the original fresh leaf.

The percentage of wither denotes the weight of 100 kg of fresh leaves at the end of the withering process. For example, if 100 kg of fresh leaf becomes 65 kg after withering, the leaves are described as being at 65% wither.

A complementary and more reliable measure is the outturn method. The outturn of made (finished) tea equals the weight of made tea divided by the weight of withered tea, multiplied by 100. This is considered more reliable than simple weight-loss measurement because the moisture content of made tea varies very little – typically 2.5 to 3.5% – when the dryer is properly operated.

Tracking degree of wither in this way allows factory managers to maintain consistency across batches and seasons. A wither that is too light (high moisture remaining) leads to problems during rolling, poor fermentation, and flat, low-quality tea. A wither that is excessively heavy can tax the dryer, damage enzyme activity, and produce tea that is more red in color than quality in cup.

Consequences of incorrect withering in orthodox production 🔗

The sensitivity of orthodox tea to withering conditions is far greater than for CTC, because orthodox rolling relies entirely on the physical state of the leaf rather than on brute mechanical force. Research has shown that a high moisture loss during withering is detrimental to the brightness, briskness, and body of the final tea, confirming that over-withering carries its own quality risks.

Under-withered leaves, on the other hand, are wet and heavy. They resist the twisting action of the orthodox roller, produce uneven cell maceration, and result in poor oxidation during fermentation. In orthodox manufacture, only internal injury is imparted to the leaf during rolling – unlike CTC where maceration is complete. This means the degree of flexibility of the leaf at the rolling stage directly determines how effectively cell contents are released to initiate oxidation.

Getting the wither right is therefore not an optional refinement – it is the foundation on which the entire orthodox tea quality pyramid is built.

Why these two steps define orthodox tea quality 🔗

Raw material selection and withering are not independent steps. They work together as a system. Fine, young leaves wither more evenly and quickly than coarse material because leaves and buds lose moisture more easily than stalks and shoots. This means starting with the right leaf grade makes the withering process itself more controllable and consistent. Conversely, coarse or uneven plucking leads to uneven withering – some parts of the leaf too dry, others still too wet – which cascades into problems at every subsequent stage.

Orthodox processing uses the wholeness of the leaf itself to create a diverse range of flavors in the cup. That wholeness is only achievable when the right leaf was selected in the first place, and that leaf was then brought to exactly the right condition through careful, adequately long withering. It is this disciplined attention to the starting conditions that separates a premium orthodox Darjeeling or Nilgiri from a mass-produced commodity tea.

What do you think? Given that orthodox tea requires finer raw material and more intensive withering than CTC, do you think the higher cost of orthodox tea is fully justified by the quality difference? And with increasing demand for premium teas globally, how might climate change affecting flush quality and withering conditions reshape the future of orthodox tea production?

References

1. https://www.halmaritea.com/blog/orthodox-tea-manufacturing-process/
2. https://www.teacupsfull.com/blogs/tea-blog/the-difference-between-ctc-and-orthodox-tea
3. https://www.harney.com/blogs/news/what-is-ctc
4. https://en.wikipedia.org/wiki/Tea_leaf_grading
5. https://foodtechnotes.com/2020/08/22/tea-processing-withering/
6. https://fareastteacompany.com/blogs/fareastteaclub/manufacturing-process-of-oxidized-tea
7. https://teaworld.kkhsou.ac.in/page-details.php?name=Withering&page=b5facb129c946e6d7971e1dc9
8. https://www.linkedin.com/pulse/green-leaf-withering-tea-md-mahamudul-alam
9. https://www.upasitearesearch.org/orthodox/
10. https://www.upasitearesearch.org/tea-manufacturing/
11. https://learning.uonbi.ac.ke/courses/AFT406/scormPackages/path_2/a32_withering.html
12. https://www.sciencedirect.com/science/article/abs/pii/S0260877415300443