The character for “fresh” is composed of “fish” and “sheep,” and as one of the five basic tastes, it's an essential part of our daily lives. When we drink tea, we often hear comments like “fresh and invigorating,” “fresh and mellow,” or “fresh and fragrant.”

So, where does the freshness come from in a simple, unadorned cup of Tea?

Chinese people have been drinking tea for over a thousand years, developing a splendid tea culture. The ways of drinking tea have varied throughout history, with countless varieties of tea, and standards for good tea have differed. However, freshness is a common consensus among most tea enthusiasts.

The Classic of Tea – Chapter Five: Boiling

“For those that are precious, fresh, and intensely fragrant, the number of bowls is three; for those of lesser quality, the number of bowls is five.”

Song Dynasty – Ding Wei, New Tea from the Northern Gardens

“The dragon tea from the Northern Gardens, sweet and fresh is the treasure.”

Ming dynasty – Wen Zhengming, Absolute Verse

“Dividing the spring sprouts before the rain of Grain Rain, wrapped in green clouds, they carry a fragrant freshness.”

Qing dynasty – Zha Shenxing, Thanks for the Gift of Pu'er Tea

“Washing away the smoky grass and trees of the hot regions, made into tribute tea, its flavor is sweet and fresh.”

The freshness of tea has been vividly described in poetry by Chinese literati.

The Secret to the Fresh Taste of Tea: Umami, the signal of proteins, is an important component, including amino acids, nucleotides, and organic acids. In the case of tea, amino acids are the primary contributors to its fresh taste, significantly affecting the quality of the leaves, and are known as “the factor of tea grades.”

There are many types of amino acids in tea, each playing its role in the taste of the infusion. For example, Theanine, serine, and proline have a sweet taste, asparagine, glutamic acid, and theanine contribute to the fresh taste, while arginine and tryptophan have a bitter taste.

It's clear that not all amino acids impart a fresh taste. However, just like in cuisine, amino acids also seek a balance of flavors. Amino acids of different taste profiles work together to create a rich layering in the tea infusion.

One particularly noteworthy amino acid is theanine, which is almost exclusive to tea and is the highest free amino acid found in tea plants. Theanine is a rare amino acid that imparts both sweetness and a fresh, invigorating taste, making it the standout member of the amino acid family in tea.

While contributing to the fresh taste, theanine can enter the brain through the bloodstream, causing a noticeable increase in dopamine, which makes people feel more energetic. It also has various benefits, such as reducing blood pressure, calming effects, and inhibiting the nervous excitement caused by caffeine.

In fact, the freshness of tea is also closely tied to polyphenols. Although the taste characteristic of polyphenols is bitterness, without them, the tea infusion lacks depth and vitality, leaving the amino acids to stand alone.

Thus, polyphenols and amino acids have a symbiotic relationship. The ratio of polyphenols to amino acids is a key indicator of the harmony of the tea infusion's taste and the suitability of the tea variety. The lower this ratio, the more pronounced the smooth and fresh taste becomes.

Additionally, the content of theanine varies in different parts of the tea plant, being higher in lateral roots, green stems, and new buds. The freshness of the leaves also affects the amino acid content; the younger and more tender the shoots, the higher the amino acid content.

Freshness is a sense of pleasure from the senses to the soul. Recognizing the fresh taste through the taste buds is a natural instinct given to humans, and the secret to the fresh and invigorating taste of tea lies within the amino acids.