Japanese Tea and Caffeine

Tea plants contain caffeine. While excessive caffeine consumption is not ideal, caffeine offers various benefits, such as stimulating wakefulness (reducing fatigue and drowsiness), strengthening the heart, enhancing endurance, preventing hangovers, acting as a diuretic, and aiding in fatigue recovery. These benefits have contributed to tea's long-standing popularity as a favored beverage.

Caffeine Content in Different Types of Tea Around the World

Not only Japanese tea but also black tea and oolong tea contain caffeine.

Depending on the reference, when comparing the extracted liquid, coffee and matcha contain similar amounts of caffeine. Gyokuro has more caffeine than matcha or coffee, but since gyokuro is not typically consumed in large quantities, the caffeine content per cup is not excessively high.

Caffeine Content in Different Japanese Teas

Japanese teas like gyokuro and matcha contain higher levels of caffeine because they are cultivated using a shading method. In particular, gyokuro is harvested from the uppermost young leaves, resulting in a high caffeine content.

For hojicha, the caffeine content varies depending on the type of tea leaves used as raw materials. Generally, hojicha is made from leaves and stems that are harvested after the initial cutting, which results in lower caffeine content. However, if high-grade sencha leaves (from the first harvest) are roasted, the caffeine content will be higher.

Leaf Position and Component Content

The higher the leaf position, the higher the amino acid and caffeine content —

Japanese tea harvesting typically involves picking the upper leaves, known as "isshin niyo" (one bud, two leaves), as they have higher amino acid content and stronger umami flavor. The table below shows the component content by leaf position, indicating that upper leaves contain more amino acids, catechins, and caffeine.

Conversely, stems have lower caffeine content but a higher amount of free reducing sugars, making kukicha (twig tea) a mildly sweet tea with low caffeine levels.

Component Content by Leaf Position (First Flush Tea, per 100g of Dry Tea)

Shaded Tea Cultivation Results in Higher Caffeine Content

When tea is cultivated using shading techniques, the caffeine content is retained, leading to higher caffeine levels than open-field cultivation.