In response to the philosophy of “bitter before sweet” in life, we have talked too much about the bitterness of rock tea. Today, let’s enjoy the sweetness of rock tea.
The sweetness in tea is not unfamiliar to us. The common floral and fruity aromas in rock tea, as well as some lesser known frankincense and milky aromas, are indirect expressions of sweetness. These “sweet sensations” can affect our oral cavity in various ways, such as varying degrees of intensity, texture, and perception time.
Where does the rich and varied sweetness in rock tea come from?
No.1The “hidden” sweetness in the variety genes
The sweetness in the variety genes can usually be divided into two categories.
One is the sweet substances in the tea leaves. There are soluble free monosaccharides and disaccharides in the fresh leaves that directly present sweetness, such as arabinose, rhamnose, fructose (0.73%), glucose (0.5%), galactose, mannose, etc. Disaccharides include sucrose (0.64~2.52%) and maltose, but maltose rarely exists in free form in fresh leaves.
In addition, other sweet substances in fresh leaves include polysaccharides such as cellulose, hemicellulose and starch, trisaccharides such as raffinose, tetrasaccharides such as stachyose, etc.
The other is the indirect sweetness brought by other substances, which can be divided into multiple types.
For example, theanine, a booster, plays a role similar to MSG, which can alleviate the bitterness of tea and enhance the umami taste, and is a real sweetness amplifier.
For example, after the contrasting players, such as catechins and tea polyphenols, give the mouth a bitter impression, the “compensatory” reaction of the taste buds makes the tongue produce a feeling of reminiscing about the bitter past and thinking about the sweet past.
There is also a key “stimulating” contestant, the enzyme in fresh leaves that can act on and release volatile aroma components.
In tea, compounds such as terpenes and aromatic alcohols are aromatic precursors with strong sweet and floral aromas. These compounds exist in the form of glycosides in the fresh leaves of tea and require the action of endogenous glycosidases to stimulate their sweet aroma potential, with β – glucosidase playing a more significant role.
The activity of glycosidase varies greatly among different varieties. In the study of glycosidase activity in hairy crabs, narcissus, and red bud bergamot, hairy crabs and narcissus had the highest enzyme activity, while red bud bergamot had the lowest enzyme activity, even with a difference of 3-4 times. This indicates that varieties like narcissus and hairy crabs have more sweet taste potential.
The reason why the sweetness in the variety gene is “hidden but not seen” is because there are very few free aroma components in the fresh tea leaves.
When we smell unprocessed fresh leaves, the term ‘unprocessed’ here refers to the state in which the tea leaves are still fresh and growing on the tea tree. Usually, we smell the green fragrance of the tea leaves or the herbal fragrance inherent in the plant, while the rich variety and form of sweet fragrance often require later processing techniques to be transformed.
No.2 The sweetness of “scheduling and stimulation” under processing technology
The sweetness brought by rock tea craftsmanship must start with the picking process. We know that different picking seasons, tenderness, weather, and other factors can affect the content of tea leaves.
As for the tenderness of picking, we previously discussed that sweet substances such as sucrose, hemicellulose, starch, etc.
usually have more content in mature leaves than in tender leaves. The activity of β – glucosidase, which plays a major role in stimulating aroma glycosidase with increasing leaf maturity, will be enhanced.
From the perspective of the picking season, terpenoids that bring rich sweet, floral, and fruity aromas are up to three times more abundant in spring than in summer. This is also one of the reasons why summer tea does not perform as well as spring tea in terms of aroma expression.
The “adverse environment” created by greening and roasting tea leaves is the main process that promotes the sweetness of tea.
When we draw blood or scratch, the clotting effect of platelets contained in blood cells can help us effectively heal the wound. Similar to the immune cells in the human body, plants also have their own immune system. In the production of tea, external “damage” caused by picking, sun drying, dehydration, and shaking can stimulate the defense of tea and induce the immune substances in tea.
Studies have shown that substances with fruity aromas, such as linalool and coumarin, have antibacterial effects on tea leaves, and glycosidases that stimulate tea aroma potential may also be key enzymes in plant defense systems.
In the process of making green tea, in an environment with high temperature (25 ℃) and low relative humidity (75%~80%), the endogenous β – glucosidase activity reaches its highest activity after 4 hours of drying. Generally speaking, the heavier the fermentation degree, the more obvious the sweetness of the tea. For example, fully fermented red tea often gives us the most direct impression of its sweetness.
The degree of baking also has a direct impact on the presentation of tea sweetness. As for cinnamon, with the increase of roasting degree, it will have a strong and lasting floral and fruity aroma around 8 hours, but the aftertaste will be slightly prominent. When the roasting degree reaches 16 hours, there will be obvious pyrotechnic aroma and aftertaste.
In the baking process, there is a proprietary term called “caramelization reaction”, which refers to the process in which sugars are converted into black brown pigment substances during heating under conditions of having “no amino compounds” and lacking water. This is similar to the process in which starch is decomposed during baking, producing various intermediates that are then broken down into glucose and undergo oxidative dehydration.
In addition to genetics and craftsmanship, the mountain environment also has a certain influence on the sweetness of rock tea. Some studies suggest that appropriate shading environment can enhance the activity of β – glucosidase in tea leaves. It is also believed that the large temperature difference between day and night in high-altitude environments is conducive to the accumulation of sugar substances in tea trees, which is a strong and direct factor in the sweetness of high mountain tea.
No.3 Is sweet tea necessarily good tea?
For the uncertain world of rock tea, the answer to the above questions is naturally ‘not necessarily’. For example, the sweet starch flavor that appears in tea leaves is believed by some experts to be the result of excessive fermentation and fiber breakdown.
For example, when we enjoyed a particularly sweet taste in our previous Maocha tea, in the eyes of the master chef, it was actually a tea that had “eaten Maohuo”, meaning that the heat in the tea drying stage had gone too fast, causing the tea leaves to consume more heat, resulting in more sugar decomposition and caramelization reactions. This sweetness often flowed onto the surface of the tea soup.
However, eating Maohuo tea has room for improvement in the delicate process, but it does not mean that this brewed tea has no future.
However, compared to the sweetness with hidden flaws in craftsmanship, the most widely accepted advanced way of sweetness in rock tea is, I think, returning sweetness.
There are different opinions about the production of sweet aftertaste. Some say that polysaccharides such as starch are broken down by amylase in the mouth for a certain period of time to produce maltose with a sweet taste; It is said that the sweetness is a compensatory response given after the passage of stimuli such as bitterness and sourness. This comfortable sweetness can surge from the bottom of the throat and re fill the entire mouth.
Returning sweetness is like a sweet rhyme. There is a saying in life that ‘sweetness is as delightful as pleasure’. Here, ‘sweetness’ seems to carry the meaning of being needed, and adding a’ return ‘adds more meaning of repeated need.
Why don’t you come and soak Lao Cong, who has a peach flavor, in water right now~