The preservation of tea has always been a major problem for tea lovers, merchants and practitioners in the tea industry.
As a beverage that is extremely sensitive to storage conditions, the maintenance of its quality is closely linked to the storage method. High-quality tea is rich in tea polyphenols, caffeine, amino acids and other nutrients and flavor substances. These ingredients not only give tea a unique taste and aroma, but also are the source of its health benefits.
However, with the passage of time and changes in the storage environment, these ingredients are prone to chemical reactions such as oxidation and degradation, resulting in the gradual deterioration of the color, aroma, taste and other quality characteristics of tea.
Conventional storage is generally refrigerated or frozen, so which method is better for preservation?
Refrigeration usually refers to storing tea in a low temperature environment of 0-5℃. Under such temperature conditions, the chemical reaction rate inside the tea is significantly slowed down.
Refrigeration can effectively inhibit the growth and reproduction of microorganisms, reduce the activity of enzymes in tea, and thus reduce the oxidation of substances such as tea polyphenols.
For some green tea and white tea with a low degree of fermentation, refrigerated storage can better maintain their fresh taste and refreshing aroma.
For example, under refrigerated conditions, the decomposition rate of chlorophyll in West Lake Longjing is greatly reduced, and it can maintain its emerald green color for a long time. After brewing, the tea soup is still clear and bright, and the taste is fresh and refreshing.
Refrigeration can also prevent the aging of tea due to high temperature, so that the tea can maintain a relatively stable quality for a long time.
Refrigeration is not flawless. Frequent opening of refrigeration equipment will cause temperature fluctuations, which will damage the storage environment of tea.
The humidity in the refrigerated environment is relatively high. If the tea packaging is not well sealed, it is very easy to absorb moisture, causing the tea to become damp and deteriorate. Once the tea is damp, it will not only affect its taste, but also may breed mold and endanger human health.
Freezing
The tea is placed in a low temperature environment below -18℃.
Under freezing conditions, the moisture inside the tea will freeze quickly, and the molecular movement will almost stop, which minimizes the risk of oxidation and microbial contamination of the tea.
For some precious tea varieties, such as Zhengshan Xiaozhong, Jinjunmei and other black teas, as well as teas that need to be stored for a long time, freezing can maintain their original flavor and quality to the greatest extent. Through freezing, these teas can still exude a strong aroma and a mellow and full taste after several years.
But freezing also has obvious disadvantages. During the freezing process, the water inside the tea leaves freezes and expands, which may cause damage to the cell structure of the tea leaves.
When the tea leaves are taken out of the freezing environment and thawed, due to the rapid change in temperature, the tea leaves are easy to absorb a lot of water, making the taste become light and the aroma is also lost.
The energy consumption of freezing equipment is high, which will increase the cost burden for merchants and ordinary consumers.
Faced with the two ways of storing tea leaves, refrigeration and freezing, it is necessary to weigh various factors.
For tea leaves that are consumed in the short term (1-2 months), refrigeration is a more appropriate choice. It can maintain the quality of the tea leaves to a certain extent, and there is no need to worry too much about temperature changes and water absorption.
For tea that needs long-term storage (more than half a year) and has extremely high quality requirements, freezing is a more reliable method, but during the freezing and use process, scientific methods must be strictly followed to minimize the impact of temperature fluctuations and moisture absorption on tea quality.
In the storage strategy of tea, refrigeration and freezing each have their own advantages and disadvantages. Only by deeply understanding the characteristics of tea and the principles and characteristics of the two storage methods, and making scientific and reasonable choices based on actual needs, can we ensure that the tea always maintains excellent quality during storage.