Huo Shan Huang Ya
I spent the afternoon doing some research and here is what I came up with.
Yellow tea, the majority of which is made high in the mountains of Anhui or Sichuan provinces, refers to a lesser known category of Chinese tea. It is a handmade tea produced similarly to green tea but it employs one additional production step known as menhuang (悶黃). Menhuang (literally "sealing yellow") is a tiny bit like the wodui (渥堆) (moist pile) step involved in the production of shu puer (熟普洱). During menhuang the tender young leaves will be wrapped with cloth or paper and kept moist and warm for the appropriate length of time (ranging from a few hours to a few days). Sometimes they are also stored in wooden boxes. The leaves will actually turn yellow (or at the least yellow-ish green) during this step.
The deeper I go into my research, the more I become conflicted. Seven Cups (an American tea company that I greatly trust) claims that "there are only three kinds of yellow tea that survive today." They go on to say that Huo Shan Huang Ya (the tea I'm sipping as I write this blog post) used to be a famous yellow tea, but is now only available as a green tea. Apparently there is a subcategory of green teas called luzhen (緑針) (green needle) that often becomes mixed up with yellow tea.
Whether I'm drinking a true yellow tea or a green needle tea, I really like this Huo Shan Huang Ya. It has a gentle, sweet, nutty flavor that tastes more mature than many green teas. I've also heard that yellow teas store well and may even be amenable to careful aging. Because of this I'm very eager to learn about (and taste!) more of them.
The Story of Tea by Mary Lou Heiss and Robert J. Heiss
Tea Dictionary by James Norwood Pratt
How Yellow Tea is Produced by Peony Tea S.
About Yellow Tea by Seven Cups
Babelcarp by Lew Perin