John,
There is really only one type of tea plant (two, depending on whether you consider them separate species)
Camellia sinensis. Then there are three main ways of processing it: if you don't roll and oxidize the leaves, it becomes green tea. If you oxidize them slightly, its Oolong tea. If they are fully oxidized, its a black tea.
All tea has caffeine, even green tea. Even de-caf. If an infusion doesn't have caffeine, it's not tea (Sorry Lance, you should call it an herbal infusion or Tisane
).
The rest of the types of tea depend on how it is processed, where it was grown, and where the tea plants originated. There are two origins, China and Assam, India. Elevation and moisture have a huge impact on the flavor of the tea.
Incidentally, Orange Pekoe is not a flavor of tea, it's a grade of tea. The orange pekeo leaves are the first 3 leaves on the new growth... they're basically the new growth on the bush. If older leaves are used, the flavor is not as good, and it gets more of a vegetable flavor. There doesn't seem to be a very good grading standard with tea, but its something like this:
OP = Orange Pekoe
BOP = Broken Orange Pekoe
FOP = Flowery (or sometimes Fancy) Orange Pekoe
GTOP = Golden Tippy Orange Pekoe
FGTOP, etc.
Generally, the more letters they stack in front of the region name, the better the grade is supposed to be.
- Matt
