Cold Brewing Tea: Cold Brewing Time for Different Tea Leaves

In the scorching summer, a refreshing cup of cold brewed tea has become a lifesaver for many people. But many people have experienced this dilemma: when it comes to cold brewing, sometimes it’s sweet and refreshing, while other times it’s bitter and bland. Is cold brewed tea really all about luck? In fact, research has already revealed that the cold soaking time of different tea leaves contains precise “flavor codes”. Only by mastering the right methods can one brew a delicious cup of cold brewed tea.

Cold Bubble Principle: Low Temperature Slow Extraction

The core charm of cold brewed tea lies in the selective dissolution of tea components at low temperatures. Research has shown that a cold water environment can prioritize the precipitation of sweet amino acids (such as theanine) in tea leaves, while significantly slowing down the release rate of bitter substances (tea polyphenols, caffeine). Data shows that under the condition of 4 ℃ cold brewing, the dissolution rate of theanine is three times higher than that of 80 ℃ hot brewing, while the amount of caffeine released is only 57% of that of hot brewing. This is also the key reason why cold brewed tea has a clear and sweet taste without bitterness.

Different types of tea have different cold soaking durations

Green tea: 1-2 hours

Green tea is a “top student” for cold brewed tea, especially varieties with high tenderness such as white tea and hairy tea. Research has shown that the optimal combination for cold soaking green tea is 25 ℃ water temperature, a tea to water ratio of 1:40, and soaking for 2 hours. At this time, the tea soup has the highest freshness, and floral substances such as linalool are fully released, giving off both the freshness of green grass and a slight sweetness. If soaked for more than 3 hours, the amount of tea polyphenols dissolved will increase sharply, and the tea soup is prone to astringency.

White tea: 1-4 hours

Different varieties are required for cold brewing of white tea: White peony can produce its best flavor in 1 hour under 4 ℃ refrigeration conditions; It takes 2 hours for Bai Hao Yin Zhen to fully release its fragrance. Research has shown that the dissolution rate of free amino acids in cold brewed white tea is much higher than that of tea polyphenols, which gives the tea soup a refreshing and sweet taste. Even if brewed for 4 hours, it will not be too bitter, but it is recommended not to exceed 6 hours [1]. In addition, the tea to water ratio can also affect the cold soaking time. When the tea to water ratio is 1:75 or 1:50, the optimal soaking time for white peony can be shortened to 30-60 minutes .

Oolong tea: 2-5 hours

The cold soaking time of oolong tea needs to be adjusted according to the degree of fermentation: for the light aroma type (such as Tie Guan Yin), the cold soaking time is 2-3 hours, and the fruit aroma is most prominent; The strong aroma type requires 4-5 hours for the mellow feeling to manifest. A study by CNKI found that when oolong tea is cold steeped for 5 hours, the water extract content reaches its peak, and the aroma level is the richest, with both orchid fragrance and honey sweetness.

Black tea: 2-3h

Black tea can be brewed cold without waiting for a long time, and enough flavor compounds can be extracted within 2 hours. Research shows that when black tea is cold brewed for 3 hours, the soluble sugar content is close to 95% of that of hot brewed tea, with a rich honey aroma and extremely low astringency, making it suitable for students who like sweet taste. If tea bags are used for cold brewing, the time can be shortened to 1.5 hours to avoid excessive tea flavor. Meanwhile, cold brewing can reduce the polyphenol content in black tea by 30% compared to hot brewing, further weakening the bitterness

Cold Bubble Practice

1. The recommended ratio of tea to water is 1:50 (1g of tea mixed with 50ml of water), which can be adjusted according to taste, but should not exceed 1:30, otherwise it may become too strong;

2. Prioritize using purified water or cold boiled water, and avoid using tap water containing chlorine, which can damage the tea aroma;

3. The refrigeration temperature should be controlled at 4-8 ℃, and it should be consumed within 24 hours after soaking to prevent microbial growth;

4. It is not recommended to cold brew heavy roasted tea or aged black tea, as the flavor of these teas is difficult to release at low temperatures and can easily produce a dull taste.

Cold brewing does not require complex operations, as long as the type and duration of tea are precisely adjusted to the appropriate rhythm, avoiding practical misunderstandings, it is easy to brew a sweet and mellow cup of good tea.