From Bud to Brew: The Minimalist Magic of White Tea
White tea is the most delicate tea because it is subject to minimal processing. Traditionally, white tea is neither rolled nor fried, so it is essentially non-oxidized, hence it is the least processed kind of tea. There are many kinds of white tea depending on the different plucking criteria, and these are mainly Bai Hao Yin Zhen (Silver Needle), Bai Mudan (White Peony), and Shou Mei (Long-life Eyebrow). White tea is mostly produced in Fuding, Zhenghe, Jianyang, and Songxi of Fujian Province in China, accounting for more than 96% of the annual world production of white tea. Nowadays, many countries and areas outside China cultivate their own versions of white tea using other tea plant varieties.
White tea is harvested when the buds on the trees are still covered with fine white hair and the leaves have not yet fully open
White tea was first recorded by Emperor Song Huizong during the Song Dynasty, dated around 1105 AD. Bai Hao Yin Zhen was very rare during the reign of Emperor Jiaqing during the Qing Dynasty and made only from the small buds of the local variety of tea tree in the area around Taimushan
Mountain in Fuding. White tea was first commercially produced from the white tea plant Fuding Dabaicha variety discovered in Fuding around 1857. The buds of this tea tree are much larger than the original variety, and have a relatively thicker covering of pekoe (downy bud tips) and a much stronger flavor and fragrance. The manufacture of white tea includes only two steps: withering and drying. It seems very simple but actually has strict requirements regarding raw materials and processing technology.
Tea Flush
Tea flush can be harvested in spring, summer and autumn; however, that obtained during the spring season is the best. Different kinds of white tea have different plucking standards. Bai Hao Yin Zhen is only single-bud, Bai Mudan is mainly plucked as one bud and one leaf or one bud and two leaves, Gong Mei is required to have one bud and two leaves or one bud and three leaves, and ShouMei basically does not contain buds. The tea leaves will begin to wilt soon after picking, with a gradual onset of enzymatic oxidation.
Withering
Withering is a key step in white tea processing, which removes moisture from the leaves and allows for a very slight amount of oxidation. This step may be allowed to take place under the sun or indoors depending on the weather conditions during the tea season. Tea masters have to constantly keep monitoring the light, humidity, temperature and air-flow to achieve high quality. The typical color of white tea, leaf shape and sweet fragrance of the silvery hair that covers the young leaves and buds is actually created during this step. Nowadays, to boost supply and hasten production, the withering of white tea is performed mechanically in factories.
Tea leaves are withering in the mild sunlight on large bamboo trays
During withering, the moisture content in tea leaves is reduced and the leaves become flaccid and pliable. Chemical changes occur inside the leaves, chlorophyll in the leaf begins to degrade, caffeine levels slowly rise, flavor and aroma volatiles develop, and the grassy aroma dissipates. The leaves also begin to break down their stored carbohydrates as an energy source. The loss of moisture also causes the cell walls to break down. The temperature increases with the respiration of tea leaves and activates polyphenol oxidase and peroxidase — triggering a process known as oxidation. All of the above changes contribute to the characteristics of white tea.
In general, the longer the wither endures, the more new aroma and flavor compounds develop in the leaves. A sign of moderate withering is that the leaf color turns dark green or gray green, the leaf margin shows dry shrinkage or is curled up, and the tip of the bud is lifted. At this time, the water content is 8-10%. In fact, many tea masters use their sense of smell and touch to determine the completion of the withering process. The manufacture of quality white tea is strongly influenced by the weather conditions. Appropriate environmental temperature is the most important factor, and it is of the major reasons for the rarity and high cost of white tea. An experienced tea master can make adjustments to the steps of withering and drying by adjusting environmental humidity and temperature. If the temperature is too hot while withering, the white tea leaves will turn reddish.
Using withering machines can greatly shorten the withering time and ensure the quality of tea leaves in rainy days
Drying
The final step of white tea processing is drying. Baking has to be performed a reasonable number of times so that the moisture content will reduce to as low as 6%. By baking at relative high temperature, the oxidation is terminated, and the isomerization of catechin will reduce the astringency of tea infusion. A sign of moderate baking is that the hand-twisted leaves are powdered, and the stems are easily broken.
Compressed white tea is the result of a relatively new style of processing. The traditional white tea is coarse and loose, which is inconvenient for transportation and storage, so the compressed white tea has been developed. For compression, loose white tea is always aged for at least one year. Then, the leaves are steamed to make them pliable and pressed into cake-shape, brick-shape, and chocolate-like shape. Compressed white teas are stored at about 40% humidity to slow down fermentation. These teas are aged for several years to bring on a smooth finish to taste with pleasant woodsy, flowery, and fruity aromas.
Compressed white tea is a reprocessed tea product manufacture from loose white tea by blending, weighing, steaming, shaping, and drying
Compression has a great influence on the type and content of aroma components. The characteristic fragrance types such as jujube and herbal fragrance are more prominent after compressing, while aged loose tea retains more typical floral and fruity aromas. The taste and aroma change in different compressed white teas can considerably vary; Bai Mudan, Gongmei and Shoumei are more suitable for compressed processing to enhance the quality, as compared with Bai Hao Yin Zhen.
There are about 50 kinds of main aroma components in white tea, including leaf alcohols, benzaldehyde, benzyl alcohol, or linalool and its oxides. The aroma components of Bai Hao Yin Zhen and Bai Mudan are similar, whilst both of them are rich in alcohols with a floral aroma. Shoumei contains more aldehydes, ketones, esters, and lactones, including ionone, dihydroactinidiolide, and methyl salicylate. Furthermore, the characteristic aroma components in different grades of white tea are also different; the characteristic aroma components of Bai Hao Yin Zhen are phenylethyl alcohol, cis-jasmone, etc.; for Bai Mudan, these are β-cedarene, β-elemene, etc; and for Shoumei, they are nerylacetone and ionone.