Japan’s entrance on the world tea stage began as soon as her trade gates were pried open by Commodore Perry before our Civil War. It didn’t take long for the United States to become Japan’s best tea customer. The rise in Japanese tea imports, beginning in 1859, was due to the direct transpacific shipping routes to Seattle and San Francisco and America’s insatiable thirst for green tea.

In 1860, American merchants were importing ten percent of their tea from Japan. By 1870, the number had grown to twenty-five percent, and by 1880, Japanese tea accounted for forty-seven percent of America’s tea imports while China supplied most of the balance. By 1890, the per capita consumption of tea in America was 1.3 pounds.

To fuel the demand, Yokohama traders brought experienced Chinese tea workers from Canton and Shanghai to introduce proper tea-making techniques and the new practice of artificial coloring. Almost all early Japanese export teas were colored using Chinese secret methods. Graphite and Prussian blue were just two of the ingredients used to enhance both Chinese and Japanese teas’ appearance.

In his 1852 book A Journey to the Tea Countries of China, Robert Fortune noted that the Chinese recipe for “enhancing” tea was to “crush Prussian Blue to a fine powder and add gypsum in a ration of three to four resulting in a light blue dye powder. Add the powder five minutes before the end of the last roasting.”

Prussian Blue, also known as Berlin Blue, was a pigment imported from Holland beginning in 1820. It is incredibly vibrant and inspired many of Katsushika Hokusai’s wood prints, including his iconic Great Wave. Japanese artists favored the use of this synthetic color, which would not lose its intensity over time. Okakura Kakuzo, the author of The Book of Tea, was a great admirer of Hokusai’s work, as was Claude Monet. The Impressionist’s home walls in Giverny, France, are lined with Japanese wood prints by Hokusai and his contemporaries.

Naive American tea drinkers were equally enthralled by the deep blue highlights found on their green teas from that far-off exotic land of Japan. They weren’t aware that their teas were enhanced for visual appeal. Tea drinkers were not being poisoned, but the dubious practice came to a quick end in 1882 when The United States passed a law prohibiting the importation of adulterated teas. The Japanese tea industry was put on notice to guard against colored and poorly made teas.

English tea drinkers had their scare with adulterated teas a century earlier as smuggling took over during King George’s taxation schemes. The British avoided all this colorful controversy by staying faithful to black teas from their new gardens in India and Sri Lanka.

After all, what good was green tea if you couldn’t splash milk into your cup?