Yellow Tea vs. Green Tea
The purpose of manufacturing yellow tea is to remove the grassy taste of green tea, and to make the leaves take on a yellow coloration.
The grassy flavor is an intrinsic quality of green tea, and is a result of the tea leaves being minimally processed after the harvest. In essence, the leaves retain most of the substances present in the leaves when they are still on the bush. The chlorophyll in the leaves both gives the rich, green color, and provides the characteristic flavor.
During the process that leads to the tea leaves becoming yellow tea, the chlorophyll is broken down and partly oxidized. The taste of the tea becomes milder, and is often described as being somewhere between white tea and green tea. The aroma is described as flowery, fresh and mild.
Yellow tea is typically harvested early in the year, before most green teas are harvested. This means that the leaves are younger, that they are still rolled up into buds, and that the leaves are smaller when rolled out. While green tea is often cut and ground, yellow tea is always sold in whole leaves, often in thin buds.
Health benefits
Yellow tea is a rare variety of tea, and not much research has been done on its health benefits. However, it seems reasonable to assume that the slightly more complex manufacturing process does not significantly reduce the antioxidant content of yellow tea, as compared with green tea.
Since yellow tea is often harvested while the leaves are still very young, they contain more antioxidants to begin with, and some speculate that yellow tea may contain more antioxidants than green tea.
These antioxidants are of the polyphenol category, more precisely catechins. These are the antioxidants that are believed to give all teas beneficial effects on physical health. Epogallocatechin (egcg) in particular is believed to have beneficial effects on cardiovascular diseases, diabetes, some cancers and mental alertness, to name but a few.
Appearance
In detail, the process of making yellow tea differs from green tea in that the yellow tea is allowed to oxidize ("ferment") for a little longer than green tea, and is then dried more slowly, often between sheets of a special paper. The result is leaves that have a light green or light yellow appearance. Some have compared the yellow tea leaves to white tea, but without the white down.
The brewed tea also looks more like white tea than green tea, and is a fluid with a warm, golden sheen. Some tea lovers feel that the yellow tinge makes the tea look more appealing in the cup. That is one reason why some prefer to drink yellow tea out of a glass cup. Some even use glass tea pots, where the leaves can be seen to stand proud at the bottom. Yellow tea is often considered able to take more infusions than green tea before losing its flavor.