All teas are not created equal.
We drum this mantra whenever an opportunity presents itself. One of the most apparent ways in which teas can differ from one other is the picking requirement, which can be explained simply as the growth stage of the tea leaf at point of harvest.
Every leaf starts out as a bud, then 1 leaf starts to grow and another, so buds are the ‘youngest’ tea leaves while picking requirements with 4 or more leaves in a stalk would be among the most matured. While physically, depending on the cultivar, tea leaves can grow up to 6 or 7 leaves, in practical terms, most leaves used in tea production seldom reach that level of maturity.
While traditional mass produced tea has always touted two leaves and a bud as the preferred grade that assertion is based on conventional commercial productions for black tea only and is overly general.
Let us look at the chemical composition of leaves according to their maturity:
The Chemistry of Tea Leaves
Composition of Flavones in Different Picking Requirements[1] (mg/g)
L-EGC D, L-GC l-EC+D,L-C L-EGCG L-ECG Total
Bud 8.67 5.88 8.52 104.69 19.32 147.08
1 Bud 1 Leaf 15.63 6.20 9.15 88.93 30.41 150.32
1 Bud 2 Leaves 18.23 4.84 9.83 76.10 28.47 137.47
1 Bud 3 Leaves 27.32 6.61 10.29 65.08 25.20 134.50
1 Bud 4 Leaves 22.47 6.06 9.90 53.37 24.23 116.03
The flavones composition is highest in youngest leaves and starts to fall after the first leaf has grown. These flavones (part of tea polyphenols), especially L-EGCG, are associated with cardiovascular metabolic health, prevention against Parkinson disease, among others which can read more about here.
Composition of Caffeine[2]
Position Composition of Caffeine (%)
Bud & 1st Leaf
3.55
2nd Leaf
2.96
3rd Leaf
2.76
4th Leaf
2.09
Stem
1.19
From the table, we can see there is an inverse relationship between the maturity of the leaves and the composition of caffeine.
Composition of Amino Acid[3] per 100g
Leaves Position Bud 2nd leaf 3rd leaf 4th & 5th leaf
Quantity (mg) 1,150 960 750 590
Putting it all together, it can be summed up as there is an inverse relationship between the maturity of the leaves and the composition of flavones, caffeine and amino acid.
What does this mean for people who hate chemistry?
We do not live in labs, at least not most of us, but these compounds make a difference to us in terms of health benefits (dirty phrase among self-proclaimed purists, I know) and the taste as well.
Simply put
- Polyphenols gives astringency- in the right proportions, gives the tea a soupy, textured body, where excessive, tastes like sandpaper scraping against the tongue (e.g. Assam CTC)
- Caffeine tastes bitter
- Amino acid tastes sweet, brisk and lively
In other words, from a gastronomic perspective, amino acid can counter the effects of polyphenols and caffeine, these 3 (among others) in ideal proportions provides a tea that is complexly bittersweet, with full body and has a brisk, refreshing sweet aftertaste. (See this article for more on the relationship between these compounds in the brewing of tea).
Picking Requirements in Different Categories of Tea
White Tea
Looking at traditional white tea, there are 3 main types which is the clearest illustration of picking requirements:
i) Silver Needles- Made from buds (with partially grown leaves removed)
ii) White Peony- Made from 1 bud to 2 leaves
iii) Shou Mei (also Gong Mei and other similar fanciful names which mean essentially the same thing)- whatever is left from above, including the removed partially grown leaves of Silver Needles
Yellow Tea
While the better known varieties- Junshan Yinzhen, Huoshan Huangya and Mengding Huangya are made from buds, there are some made from more matured leaves, e.g. Taishun Huangtang.
Green Tea
Typically higher grade tea leaves are made from buds or 1 bud to 1 or at most 2 leaves ratios.
For example, if it exceeds 1 bud to 1 leaf, it cannot be sold as a Biluochun.
There are some notable exceptions though such as Taiping Houkui which is made from 1 bud to 2 leaves and Luan Guapian.
This is why for green tea, markers like Pre-Qing Ming (明前) are often used to denote tenderness of tea, although there are limitations which you can read about here.
Oolong Tea
Traditionally oolong tea is made from matured leaves- 3 to 4 leaves ratio- as the large matured leaves are better suited for the ‘zuo qing’- that is rattling (or equivalent)- process.
Black Tea
In the past, the favored picking requirement is 1 bud to 2 leaves, though ever since the Jun Jun Mei craze, buds have become increasingly popular, such as Qimen Haoya and certain Dian Hongs.
Dark Tea aka Post-Fermented Tea
Heicha such as Puer, traditionally have been made from matured leaves as those are more suited for compression although in recent years, buds have been used to make Gong Ting Puer for example.
Stems
Stems add an interesting dimension. Take a look at this table:
Compound 1st leaf 2nd leaf 3rd leaf 4th leaf 5th leaf Stems
Polyphenols (%) 16.97 20.08 18.22 16.05 12.88 10.39
Amino acid (mg/g) 150.50 146.00 127.80 100.00 94.70 147.20
Catechins (mg/g) 124.25 112.58 101.45 88.48 - 62.94
Table extracted from 制茶学by安徽茶学院published by 中国农业出版社 page 36
The most classic example would be the Japanese green tea Kukicha which is made entirely from stems.
Closer to home one example would be Taiwanese Oolong. Because their ‘zuo qing’ is largely mechanized, the leaves do not need to be separated from the stems and Taiwanese High Mountain Oolongs have their stems intact in 2-4 leaves stalks, adding the extra sweetness that is favored by lovers of Taiwanese High Mountain teas.
This is just a matter of preference though, Chinese oolong producers, especially Yancha, separate the stems from the stalk to allow for a more even ‘zuo qing’, as seen from the reddish edges on the leaf, as well as create the complexity beloved in Yancha. In the production of Dancong, some stems are added to the mix to reduce the astringency that is common in Dancong.
Claim of intact stalks being symbols of quality, as I have read, is only applicable to Taiwanese High Mountain teas due to their production intent and is not true across the board.
Conclusion
Picking requirement is only part of the equation- cultivar, soil, elevation, production all come into play as well- and unless you are eating the leaves whole, brewing methods are part of the consideration.
However it is interesting to take note of how the picking requirements affect the characteristics of the tea, especially since this is one aspect that is literally visible to the naked eye.
[1] Table taken from 茶学神生物化学edited by 宛晓春published by 中国农业出版社 page 108
[2] Anhui Tea Institute, 1984
[3] Table taken from 茶学神生物化学edited by 宛晓春published by 中国农业出版社 page 92