Fu brick tea is harvested during the hottest days of Summer, this makes it unique among other types of tea that are usually best harvested in Spring. The harvest time strongly influences the subtle and physical characteristics of fu zhuan cha. Biochemically, tea leaves that are picked in Summer have more fluorine, catechins, and are therefore more bitter and contain larger, dark green leaves. The bitter taste is surprisingly absent from all fu zhuang cha as it is eliminated through fermentation of the leaves. The high fluorine levels however can cause bone weakening especially later in life if this tea is consumed daily (see here and here). The Summer tea leaves used for fu zhuan cha also grow slower and have more of a warmer thermal nature, having absorbed the heat of the hot Summer sun.
What gives fu zhuan cha its regulating, harmonizing, centering, and grounding properties is its special production method. Its production is rather complex and involve twelve steps which include: fresh picking of leaves, panning, pile fermentation, rolling, drying, softening with steam, piling, partitioning, pressing into bricks, fungal fermentation, drying, packing and storing. In the end there are many pro-bacterial flora that proliferate in the finished tea the most commonly recognized is the eurotium cristatum bacteria which produces fu zhuan's famous "golden flower" yellow mold. It is famous because it is most noticeable to the naked eye. However many other bacteria are found in fu brick tea, and not all brick tea contain golden flowers.
Fu zhuan cha has a special affinity for the digestive center, the Earth Element. This is partly because of its slightly warming thermal nature which fortifies digestion in the body but mainly because of its bacterial content. According to the theory of the Five Elements, Yellow is the colour of the Earth Element and the Stomach and Spleen are the organs of the Earth Element. It is no wonder that the quality of a particular brick is often measured by the amount of "yellow flowers" contained in the brick. The Earth Element is also connected to the Late Summer season and the change of season at the equinoxes and solstices. Fu zhuan's strong centering qualities allow us to get through these periods of change with its stabilizing qualities. As a result it is the tea that best harmonizes us with this season.
Its mild, unpretentious taste and smell neither impart too much yang not yin, helping to again stabilize us along the path of the middle way. Fu tea contains a mild sweet taste. The sweet taste is said to be the taste of the Earth Element further harmonizing it with these energies.
Traditionally this tea has been used to aid in digestion by remote Tibetans and Mongolians. Recently it has been found that the bacterial cultures in fu zhuan cha increase protein and carbohydrate metabolism, while preventing the absorption of fat in the body. Years ago Japanese studies have shown fu tea to be the best tea for weight loss which is probably due to this newly discovered effect.