The storage and aging process is a critical step for raw Pu'er Tea, as it transforms the tea not just in terms of storage, but also in its journey towards becoming more fragrant, mellow, sweet, smooth, and moist. Beyond increasing the value of aged Pu'er tea, let's explore the changes that aging brings to raw Pu'er tea.

To understand how to store Pu'er tea, we first need to know about the factors that affect the aging process:

1. Moisture

The most important condition for the aging of Pu'er tea is moisture, which directly impacts the quality of the tea.

(1) Moisture content in the tea: This is the primary factor affecting quality changes. Water plays a crucial role in the aging process of Pu'er tea, but if the moisture content exceeds a certain level, higher moisture levels lead to faster rates of unfavorable changes in quality.

(2) Air humidity: This is an essential factor in the formation of good Pu'er tea quality. To achieve high-quality Pu'er tea, the annual average humidity should be controlled below 75%. Therefore, it's important to ensure proper ventilation to reduce moisture when aging Pu'er tea.

2. Temperature

The aging of Pu'er tea is a gradual process, so the temperature should not be too high or too low, ideally between 25°C and 30°C. Higher temperatures can accelerate oxidation and reduce the effective components, negatively impacting the quality of the tea.

3. Light

Light can cause changes in certain chemical components within the tea. Exposure to sunlight can significantly alter the color and taste of the tea, diminishing its original flavor and freshness. Therefore, Pu'er tea must be stored away from direct light.

4. Air

Clean air is beneficial for the formation and maintenance of good Pu'er tea quality. The environment in which the tea is stored is very important: circulating air with a higher oxygen content supports the proliferation of certain microorganisms, accelerating the development of desirable qualities in Pu'er tea.

What Changes Occur in Raw Pu'er Tea After Aging?

1. Aroma

Pu'er tea is renowned for its unique quality of “becoming more fragrant with age,” earning it the title of “drinkable antique.” This is also a key factor in determining the price of aged Pu'er tea on the market. Under suitable storage conditions, Pu'er tea does indeed develop roasty, phenolic, aged, and woody aromas during the aging process.

2. Sensory Characteristics

During storage, raw Pu'er tea undergoes changes in color, taste, and aroma due to factors such as moisture, temperature, and sunlight. The liquor color changes from greenish-yellow to reddish-yellow, the aroma evolves from fresh to aged, and the sun-dried character diminishes or disappears entirely.

3. Soluble Extract Content

Soluble extracts include polyphenols, soluble sugars, amino acids, Caffeine, and water-soluble Pectin, among others. The level of water-soluble extracts reflects the amount of soluble substances in Pu'er tea, indicating the thickness and strength of the tea liquor. However, there is currently no definitive conclusion regarding the relationship between aging time and the quantity of soluble extracts.

4. Caffeine Content

Caffeine, one of the characteristic compounds in tea, is the most abundant alkaloid. Research consistently shows that caffeine decreases over time during tea storage.

5. Liquor Color

Pu'er tea contains large amounts of polyphenols, a group of compounds, with catechins being the main component. These compounds are closely related to the color, taste, and aroma of the tea. Catechins are colorless, have a bitter and astringent taste, and are highly stimulating. During storage, they undergo autoxidation, initially losing hydrogen to become quinones, which then further polymerize into brown pigments. These combined pigment changes contribute to the gradual darkening of the tea liquor.