Why Does Vietnamese “Trà Móc Câu” Have Curved Leaves, While Japanese Green Tea Is Straight?

A friend of mine who loves Japanese green tea once asked: why do the tea leaves of Trà Móc Câu from Thái Nguyên, Vietnam, curl into hook-like shapes, while Japanese green tea leaves are needle-straight? The answer lies in both processing methods and cultural preferences.

The shaping process – rolling technique

In making Trà Móc Câu, after fresh leaves are harvested, withered, and heat-fixed to stop oxidation, they go through a step called rolling. The tea maker places the leaves on a bamboo tray and rolls them in circular motions. This breaks the leaf surface so flavor can be released more easily when brewed, and at the same time, it causes the leaves to curl. Once dried, the leaves retain their hook-like form.

In Japan, green tea also goes through rolling, but the technique is different. The leaves are rolled lengthwise instead of circularly. This makes the tea leaves straight and needle-like, which is why Japanese sencha has such a distinct appearance.

Practical benefits of curled tea leaves

• Better preservation: Curled leaves have less surface area exposed to air, which slows oxidation and helps the tea keep its aroma longer.

• Less breakage: The curved shape distributes pressure more evenly when packed together, preventing the leaves from crumbling. When brewed, the leaves unfurl gracefully, staying intact.

A matter of culture and aesthetics

Every tea culture has its own style. In Japan, straight tea leaves are considered elegant. In China, tea leaves may be straight, curled, or even rolled into pearls. In Vietnam, however, consumers are familiar with the hook-shaped leaves—thin, curled, and resilient—which have become a symbol of high-quality tea.

When brewed, Trà Móc Câu slowly expands, returning to the form of fresh tea leaves. This not only brings a rich flavor but also adds visual beauty to the tea experience.