Optimal Storage Conditions for Tea: Maintaining Quality and Freshness

Low temperature storage

Excessive temperatures accelerate the process of automatic oxidation in tea, leading to significant changes in aroma, soup color, and taste. Additionally, certain water-soluble substances abundant in tea may become insoluble or difficult to dissolve in water, while the aromatic compounds within the tea are also destroyed. As the storage environment's temperature increases, the deterioration of tea occurs more rapidly, resulting in a deepening and dulling of its color. Therefore, in order to ensure tea quality and extend its shelf life, it is necessary to store it in a cool environment.

Storing tea leaves at lower temperatures minimizes the oxidation activity of various components and slows down the aging process. Generally, a temperature range of 0°C (32°F) to 5°C (41°F) is considered ideal for tea storage.

Avoid light

Exposure to light adversely affects the quality of tea as it accelerates various chemical reactions within the tea. Tea leaves contain a substantial amount of chlorophyll, which easily fades upon exposure to light. Moreover, light exposure triggers photosynthesis, leading to oxidation and deterioration of the tea leaves, resulting in a deepening and darkening of their color. Furthermore, a small quantity of carotenoids found in tea serves as an essential auxiliary component in photosynthesis while also absorbing some light energy. However, intense light irradiation promotes their oxidation, causing the carotenoids to emit a distinct odor that alters the aroma of the tea infusion. Therefore, it is crucial to store tea leaves in a manner that minimizes light exposure to prevent photosynthesis of chlorophyll and other components in the tea leaves.

Image Credit: Ivan Samkov

Dry and cool

Tea exhibits a strong hygroscopic nature, readily absorbing moisture from the surrounding air. During the summer season, with elevated temperatures and increased microbial activity, it becomes crucial to prevent tea leaves from exceeding a moisture content of 10%. If the moisture level surpasses this threshold, the tea may become moldy and completely deteriorate, losing its original color and aroma, rendering it undrinkable.

When dry tea leaves are exposed to the air indoors, their water content can rapidly increase. For instance, in a humid environment on a rainy day, each hour of exposure to the air can cause the tea leaves to absorb an additional 1% of moisture. Once tea absorbs excessive water, it may lose its fragrance under mild conditions or, in severe cases, deteriorate and develop mold. To address this, damp and moldy tea leaves should not be directly exposed to sunlight. Instead, they should be placed in a clean iron pot and stirred continuously with a frying spoon within the pot until the tea leaves gradually dry out and emit their characteristic aroma.

Therefore, it is imperative to ensure that tea leaves are stored in a dry environment right from the outset, shielded from any moisture. Drying serves a dual purpose: firstly, the storage environment for tea leaves should be relatively dry, and secondly, the moisture content of the tea leaves must be controlled within a specific range prior to storage. Typically, high-quality tea leaves are maintained with a moisture content below 3%. If the tea leaves contain excessive moisture, they ought to be dried before storage. Similarly, the dried tea leaves also require storage in a cool, dry, and well-ventilated location, thereby minimizing the aging and deterioration of the leaves to the greatest extent possible.

When it comes to household tea consumption, it is common to purchase tea in small packages, such as cans, tins, or compound film bags. Regardless of the packaging type, it is crucial to store the tea in a dry location. In the case of bulk tea leaves, they should be layered with clean white paper, packed into jars or containers, and supplemented with a desiccant. The jars or containers should then be tightly sealed to ensure proper storage.

Insulate the air

Tea not only readily absorbs water but also reacts swiftly with oxygen in the air, leading to its rapid aging. Moreover, tea exhibits a strong adsorption capacity, necessitating effective isolation from the surrounding air during storage. Tea can easily absorb external odors, thereby compromising its own fragrance. To ensure optimal tea storage conditions, it is advisable to allocate a dedicated refrigerator exclusively for tea. In cases where tea needs to be stored alongside other items, it is crucial to completely seal the tea leaves and refrain from placing any strongly scented items nearby, such as camphor balls, medicines, cosmetics, and the like.