Umami
Umami is the savory, brothy taste in tea, strongest in shaded Japanese greens like gyokuro and matcha and driven largely by L-theanine and other amino acids.
Definition
Umami is the fifth basic taste, alongside sweet, sour, salty and bitter. The Japanese chemist Kikunae Ikeda named it in 1908 after isolating glutamate from kombu seaweed. In tea it reads as a savory, brothy, sometimes seaweed-like depth that coats the tongue rather than sitting on it. The main source in tea is free amino acids, above all L-theanine, which is close to unique to the tea plant, plus smaller amounts of glutamic acid and aspartic acid. Theanine forms in the roots and moves to the new shoots. Sunlight converts part of it into catechins, so anything that limits light keeps more theanine in the leaf. That is why shaded teas such as gyokuro, kabusecha and the tencha used for matcha carry far more umami than sun-grown sencha. Umami is also sensitive to brewing. Amino acids dissolve readily at low temperatures, while catechins and caffeine, which bring bitterness and astringency, extract faster as the water gets hotter. Brewing a high-umami tea cool shifts the cup toward savory and sweet. Brewing it hot buries the umami under bitterness.
In Depth
To get the most umami from gyokuro, use 6-10 g of leaf with 60-80 ml of water at 50-60°C (122-140°F) for around 2 minutes. Good sencha shows umami at 70-80°C (158-176°F) for 60 seconds. Above about 85°C (185°F) the catechins take over and the broth turns sharp.
First-harvest (ichibancha) leaf holds more amino acids than later harvests, because the plant stores nitrogen over winter and pushes it into the spring shoots. Heavy nitrogen fertilization, common in Japanese tea fields, raises theanine further. Roasted teas such as hojicha lose most of their umami, since heat breaks down the amino acids.
Do not confuse umami with sweetness. A cup can be sweet without being savory. If the taste lingers at the back and sides of the tongue and makes you salivate, that is umami. Overcooked spinach or burnt seaweed notes mean the water was too hot or the leaf sat too long.
See Also
- Japanese Green Tea
- Amino Acids in Tea
- Shade-Grown Tea