Where does the Sweetness and Bitterness of Tea Come from?


In the previous article: “What are the causes of brewed tea aromas?”I talked about how tea is brewed to taste. Although sweet, sour, salty, spicy, bitter, and astringent are the tastes most commonly associated with food; bitter, sweet, and a category of flavours known as ‘umami’ are what define the taste of tea.

This article will tell you why tea tastes bitter, sweet, and umai, and explain how to tell if tea is still fresh, and which flavours are natural to tea. If you are a fan of tea, let us read on together!

Where does the Sweetness and Bitterness of Tea Come from? - ABoxTik 一盒精品 2

Do you know The Taste of Tea?

Where Does the Bitterness in Tea Come From?

The main compounds responsible for the bitterness in tea are catechins and caffeine, both of which, when fermented, turn into tannins. Catechins are chemical substances that plants use to protect themselves from sun damage. Catechins are also the primary form of antioxidants in green tea, and although beneficial for your health, they are one of the most bitter compounds in tea.

When tea leaves undergo oxidation, as in the production of black tea, these simple catechins link together to form larger polyphenols, also known as tannins, imparting a unique taste, astringency, and reddish color to black tea. Catechins have the highest concentration in green tea and the lowest in black tea. For Japanese green tea, catechins make up about 11-17% of the water-soluble components of processed tea leaves.

For example, in sencha, catechins typically fall around 15-17%, while in teas like gyokuro, the catechin content is lower, approximately 11-12%, which is one reason why gyokuro is not as bitter as sencha.

Another bitter compound is caffeine. While caffeine is not as bitter or widespread in tea leaves as catechins, caffeine binds to at least six different bitter taste receptors on the tongue.

However, since everyone’s genetics are different, the perceived bitterness varies from person to person, so some people may find certain teas bitter while others do not. Natural caffeine is bitter, and the more caffeine in tea, the more bitter it will be.

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What Causes the Bitterness in Tea?

Tannins present in tea cause bitterness. However, tannins are an essential component of tea flavor compounds, giving tea its characteristic taste. The tannins in tea need to achieve a good balance during the production process; too much tannin can upset this balance.

Some describe tea, like wine, as a balance of bitterness, sweetness, and astringency. In the mouth, tannins can cause a rough and dry sensation, similar to biting into an unripe fruit or the astringency experienced when tasting a dry red wine.

The amount of tannin in tea varies depending on the oxidation level of the tea. Black tea has the most tannin, especially the Assam variety, known for its high tannin content. Assam tea is often described as thick, robust, and somewhat sweet despite its higher tannin levels. Although tannins can make tea bitter, they are essential for preventing tea from being bland.

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The Taste of Tea, a melody that dances on your taste buds, each note a symphony of nature’s sweetest nuances. With every sip, let the essence of leaves serenade your senses, a journey where the teacup becomes a vessel for the poetry of flavors.

Where does the Sweetness and Bitterness of Tea Come from? - ABoxTik 一盒精品 4

What is The Taste of Tea?

Freshness in Tea

The freshness in tea comes from amino acids, which are components of proteins. Tea amino acids or L-theanine is the most abundant amino acid in tea leaves, constituting over half of the total amino acids.

It decomposes when exposed to sunlight, which is why we often describe high-mountain tea with misty surroundings to have more sweetness. This is because there is less sunlight, resulting in relatively higher levels of theanine.

Theanine imparts sweetness and freshness to tea, and when consumed with caffeine, it produces a calming and focusing effect. Theanine is a significant contributor to the refreshing and sweet taste of tea.

Japanese green teas, such as matcha, sencha, and gyokuro, are often considered to have the most freshness. Amino acids typically make up 2-3% of sencha and 4-5% of gyokuro and matcha. In some exceptionally high-quality matcha, theanine content can exceed 10%!

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Sweetness in Tea

The sweetness in tea comes from carbohydrates such as sucrose, fructose, and glucose, all of which are present in tea leaves and are products of photosynthesis. Additionally, amino acids can combine with sweetness, meaning teas with higher freshness levels also taste sweeter. Another special sweetness related to tea is the aftertaste, known as “hui gan” in Chinese and “yūin” in Japanese. This type of sweetness can be produced by various compounds, one of which is 2,4-dihydroxybenzoic acid, which is more abundant in colored teas, enhancing the sweetness of tea leaves.

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The Taste of Tea, a symphony of nature’s sweetness encapsulated in every drop, where each sip whispers the poetry of dew-kissed mornings and sunlit meadows, a dance of flavors that lingers on the palate like a gentle serenade.


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How to Identify Freshness of Tea Leaves

  • Appearance of Tea Leaves

By examining the appearance of tea leaves, you can quickly determine their freshness. If you notice broken leaves, the quality may not be as good as intact leaves. Also, the presence of stems and wood particles can diminish the flavor of the tea. Broken leaves can impact the complexity of the tea, and the color of the leaves is essential—darker leaves often indicate less freshness.

  • Aroma of Tea Leaves

Another aspect to consider is the aroma of the tea, as it is one of the simplest ways to determine freshness. Fresh tea leaves have a crisp, floral, and fruity aroma, and the aroma of high-quality tea lasts longer than that of ordinary tea. You don’t necessarily have to brew the tea; just pick up the leaves and smell them to gauge if they are still fresh. If you can detect a faint tea fragrance, the leaves are still fresh. Conversely, if you notice a damp, musty smell, the tea may no longer be fresh.

  • Texture of Tea Leaves

Touch is an excellent way to determine if leaves are still fresh. Fresh leaves should feel smooth, and they shouldn’t break easily. If the tea leaves feel somewhat moist and soft to the touch, it’s a warning sign that the tea may no longer be fresh. Quality dried tea leaves should have a smooth, intact, and firm texture.

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Signs of Tea Leaves Going Bad

  • Acidic Smell or Taste: Bacteria can produce unpleasant odors. If your tea has this smell, it likely contains bacteria, and it’s not advisable to consume.
  • Mold Symptoms: Mold can grow on tea leaves in various ways, thriving in storage environments with a relative humidity exceeding 65%. Mold may have a strong smell, but some types are not easily detectable. If your tea has a bad taste, it may have molded.

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Where can I buy fresh tea? ABoxTik gives you the best quality tea series

Tea comes in many different tastes, but regardless of which variant it may be, it is crucial that the quality of leaves are strictly checked by growers and manufacturers to ensure a pleasant taste with maximum health benefits.

Every one of ABoxTik’s tea has passed government inspection and qualification standards, and is carefully selected from the most authentic tea regions in Taiwan which clearly shows in the quality and texture! Welcome to ABoxTik’s official website to place an order for the best of what Taiwan has to offer now!