Even after thousands of years being brewed by a major portion of the world, there are still new things to discover about tea. Tea merchant Bill Waddington recently discovered one of Western China’s hidden secrets: dark tea.

Lynne Rossetto Kasper: Where have you been and is there a new revelation for you?

Bill Waddington next to a log of dark tea

Bill Waddington: I’ve been in Western China, which doesn’t get many visitors, especially tea merchants, even though they’ve been making tea there for about 2,000 years. One thing I discovered when I was there was that I have led you astray over the last couple of years. I’ve always told you there are five categories of tea: black, oolong, green, white and pu-erh. Pu-erh is that real earthy tea. I was wrong, and I just learned it over the last few years.

LRK: It’s not just that you’ve been leading me astray; this is what most books tell you are the categories of tea.

BW: Absolutely -- and they’re wrong. There are five categories of tea: black, oolong, green and white, but not pu-erh. The fifth category of tea is something called dark tea, and I just stumbled across it about 4 or 5 years ago in Western China while looking for strange teas. Boy did I find an unusual tea.

LRK: What is dark tea?

BW: Dark tea -- the Chinese name is “hei cha,” literally dark tea -- is any tea that goes through a secondary fermentation process, sometimes called a post-production process. In other words, they make a tea, typically a basic green tea, and then they go through a secondary manufacturing process.

LRK: You’re going to have to walk me through this. Green tea is made how?

BW: Green tea is made through a little bit of withering, a little bit of drying and a little bit of shaping of the leaf; that’s about it.

LRK: So there’s no fermentation? It’s just dried and then it’s sort of heated?

BW: It’s fired at the end to kill any enzymes in the plant so the leaf doesn’t break down.

LRK: Then what happens to make it dark tea?

BW: Then they’ll take that tea and they’ll put it through a secondary fermentation process; a slight fermentation occurs in the beginning, but they’ll go through a post-production fermentation process. Two interesting things happen during this secondary process. Number one, a microbe, a living organism or a microorganism, naturally comes into the tea leaves during this secondary post-production process, so it becomes a probiotic product. Also, aging is involved, so it’s done over a period of time. You have this microorganism working on the tea leaf over a period of time from a couple months to years sometimes, and it changes the very nature and the chemistry of the leaf and the liquor itself. It’s pretty astounding. Pu-erh at a tea shop in Beijing I should mention pu-erh is a sub-, sub-category of dark tea, but what I discovered on my recent journeys is the world of dark tea is much, much larger than just pu-erh. There are all these other dark teas that are in China, almost all made in Western China, that the West, Europe, the Americas, have never seen before. There are two or three gigantic mountain ranges and 2,000 miles between where these teas come from and the sea coasts where Europeans and Americans have always bought their teas. They’ve made these teas forever, but they always shipped them west to Tibet, Mongolia, and eastern Russia. They’ve been around forever, but it’s a long way to get these teas to the sea coast, so they always shipped them the other direction. Americans and Europeans just know the teas from the coastal regions.

LRK: Are they very rare?

BW: These were originally produced by the government 1,400 years ago, and they’re an everyman tea. They wanted the common people of China to have a really nice tea so these are not expensive teas, which I love, and they’re definitely geared toward everyday consumption. But they’re wonderful flavors.

LRK: How are they drunk? Do you have these with food?

BW: They’re drunk all day long. They’re often drunk after meals as almost a digestive. I wouldn’t make any health claims on that, but the Chinese swear it and it does taste and feel wonderful. The dark tea “hei cha” is a great all-day drinking tea. The first steeping of the little cube of tea barely breaks apart the tea leaves. You can re-steep this tea literally five, six, seven, eight times. Just re-steep the same leaves.

LRK: You have brought into the studio a log of dark tea that is 2-and-a-half feet long and it’s in a cloth sack and a bamboo holder. It is about 5 inches across; it looks about the size of a rolled-up yoga mat.