About five centuries ago, tea arrived in Europe as a rare Oriental medicine and a luxury so precious it was called "green gold." This episode of Traces of China II follows the extraordinary journey of this ancient Chinese leaf, revealing how it quietly transformed the modern world.

At Britain's oldest tea garden, Tregothnan Estate, horticulturalist Jonathan Jones demonstrates the delicate art of hand-picking and withering tea leaves. Nearly two acres of tea trees at the estate were introduced from China, from the country's eastern coast all the way to Yunnan.

In Cambridge, historian Alan Macfarlane offers a striking revelation: without Chinese tea, there might have been no Industrial Revolution. Boiled tea made polluted urban water safe to drink, sustaining Britain's growing cities. In factories, tea breaks kept workers focused and fueled production.

Britain became one of the Western nations that embraced tea most fervently. From London's refined afternoon teas to the worldwide craze for bubble tea, the episode shows how a simple leaf bridged cultures and reshaped economies.

Tea's story is one of exchange and evolution — from an ancient Chinese medicine to one of the world's most consumed beverage. Along the way, it carried with it traces of Chinese artistry — porcelain, silk, and aesthetics that still color European life today.