WHY Does My Green Tea Taste So GOOD?! (Part 1)

If you are a lover of tea, then you have likely had a cup of tea that made you go “wow.” That moment of tea-induced bliss is where the life-long passion for tea often begins. But why in particular was that cup of tea so especially delicious? What contents of that brew made it so enjoyable to drink? Why do some cups make you say “wow” and others make you say “meh.” We will attempt to answer these questions and more by breaking down what constructs green tea flavor, and what can make green tea flavor great.

First and foremost; tea polyphenols. Most polyphenols in tea belong to a category called catechins, also known as tannins, which represent about one-third of all solids in green tea. Tannins exist in many other foods and beverages, such as red wine. They are bitter or astringent in nature, and play a big part in determining the “strength” in green tea flavor. Tannins need to be abundant enough in the tea infusion so that flavor is not too weak, or thin. Contrarily, too high a tannin content and the infusion will be unpleasantly bitter or astringent. Probably most of us have had tea in the past that was too tannic. These overly tannic tea infusions can be a result of tea tree growing conditions, and/or over-steeping the tea. Higher water temperatures, and longer steep times pull more tannins out of the leaves. So, a big reason why that green tea infusion made you say “wow” is that the leaves were not scorched, or over-exhausted, which kept the tannins in check. Sources in China tend to agree that tannin content in green tea is best right around 20%-24%.

The next green tea compound is what separates “good” from “I want to CRY that it so good.” Amino acids. Amino acids stand for only 1%-4% of solid compounds in tea leaves, but account for most of the savory and sweet flavor in green tea. The pleasant flavor of amino acids is what serves to mask some of the bitterness introduced by tannins. There have been 26 different amino acids discovered in tea leaves so far, theanine being the most prevalent among those (accounting for 50%-70% of all amino acids). Amino acids are essential to plant health, as they serve as building blocks for other components in leaves, like proteins, tannins, and aroma compounds. This means that savory amino acids can actually be transformed into bitter tannins under certain growing conditions. For that reason, a primary objective in green tea production is minimizing the conversion of amino acids into other compounds, like tannins. So, we can most likely assume that when you drank that memorable cup of green tea, smacked your lips together in satisfaction, and said “YUM!”, it was the doing of a tea infusion with particularly high amino acid content.

You might be thinking, “if tannins should be kept on the low end, and amino acids on the high end, then there must be an ideal ‘tannin to amino acid ratio,’ a quantified value, that we are seeking.” And to this I would say, “you are bizarrely perceptive, and exactly right!” The tannin/amino acid ratio is a figure that is commonly calculated when running quality control testing on batches of green tea. Ideally, this tannin/amino ratio should be kept as low as possible. It is worth emphasizing that this is a ratio, meaning that a great green tea can still have a high amount of tannins, so long as there is also a high amount of amino acids to balance things out.

To recap, our “wow” flavor is coming from a tannin content between 20%-24%, accompanied by however many amino acids that little tree can pump out, ultimately bringing the tannin/amino ratio as low as possible.

What else creates that mouth-watering flavor in our teacup? Sugar! Soluble sugars team up with some amino acids to provide sweetness to the tea infusion. Sweet is not the typical flavor attributed to green tea, however tea leaves do contain a sizable portion of carbohydrates (20%-25% of solids). These carbohydrates include cellulose, starch, glucose, etc., which can be broken down into soluble sugars that add a touch of sweetness to your tea. Soluble sugars, along with sweet and savory amino acids, serve to counteract bitterness/astringency in green tea, providing a flavor profile that is strong, brisk, and refreshing. In addition to adding sweetness, soluble sugars and amino acids are relatively viscous, enhancing the roundness and thickness of the mouthfeel. The sweet, savory, and viscous attributes of sugars and aminos balance out the bitter and astringent tannins to orchestrate polyphenol perfection, bringing about a sip followed by a “yum.”

To read part 2 of this series, click here!