The production of Silver Needle White Tea as we know it today dates back to the early Qing Dynasty (1796) and was at that time picked from wild tea buds in the Fuding region of Fujian. These fine tea leaves were of course only for the Emperor and his closest administration. At that time only the first leaves in spring were picked. Today Silver Needle is grown and harvested in a fine plucking (where only the buds are selected) in Fuding, Zhenghe and Jianyang regions. However white tea is also found outside China – like in Darjeeling, but the true originals are still from Fujian.
In China this tea is steeped in a gaiwan or a small tea pot (yixing or similar). And the ration tea to water is around 10 g of tea to 1.5-1-7 dl of water. Which is quite a lot of tea especially when we talk about white tea that is very bulky. First the tea is rinsed quickly in fresh, good tasting spring water (around PH 7) and then steeped for several short infusions, from 30 seconds to 1 minute the first steeping, to longer the second, third and fourth time. Since the tea ratio to water is very high shorter steeping time is enough. The quality of the leaves will tell the tea master/tea sommelier how many steepings that can be obtained.
In the west (and especially in cafes and restaurants) we normally use less tea and more water, and therefore we let the tea steep longer. 3 g of tea / 2 dl water is a common rule. In this case with the white tea, Silver Needle you did absolutely right to steep it longer (2 min). And then you steeped the tea a second and a third time to see how it changed. Probably the tea became quite weak the third time. In my opinion when we steep the western way, whit the type of tea that we normally serve in the west, 1 – 2 steepings is the normal procedure. The first steeping of this silver needle could even been a bit longer (up to three minutes) and the second then up to 5 minutes or even more. White tea is very low in tannins. The aroma and taste of silver needle is as you point out very delicate and is often described as fresh cut flowery hay (that comes from the steeped leaves) and the infusion / liquid as a combination of flowery and vegetal (like clover and wheat grass), with sweet honey notes and stone fruit in the finish. The light tobacco that you sense can also be there, depending on how much oxidation the buds have undergone during the slow drying. The White Hair Silver Needle (or just Silver Needle if a slightly lower grade) – Bai Hao Yin Zhen in Chinese are the least processed tea of all, the buds are harvested carefully, then withered to reduce moisture and then slowly shade dried (where they oxidize slightly around 5%).
White tea is said to have been enjoyed by the monks before they mediated early in the morning, because the L-theanine that is found in early harvested teas, stimulate the production of Alfa waves in your brain, the same effect you get when you meditate – you become very calm and relaxed, yet aware and awake.
In China the tea sommeliers never use thermometer nor a timer. They use their senses that develop over time when they have steeped a lot of teas. But of course here in the west we need some guidelines, especially to guide guests & customers to the best result.