To this day, the water temperature and quality for brewing tea are highly particular. When boiling water for tea, it should be done quickly over high heat, not simmered slowly. Water that has just reached boiling point is ideal, as it brings out the best aroma and flavor in the tea. Over-boiled water, referred to by the ancients as "old water," loses all dissolved carbon dioxide, significantly diminishing the tea's freshness. Under-boiled water, called "young water" by the ancients, is also unsuitable for brewing tea, as the low temperature fails to extract the tea's full flavor, resulting in a weak taste and leaves floating on the surface, making it inconvenient to drink.

The steeping time depends on the amount of tea leaves used. More leaves require shorter steeping, while fewer leaves need longer steeping. The number of infusions also varies accordingly. Shorter steeping allows for more infusions, while longer steeping reduces the number of infusions.

1. Differences in the expression of tea characteristics:

For example, brewing green tea with water that is too hot reduces the lively, infant-like quality of the tea. Brewing Baihao Oolong with overly hot water diminishes its delicate, feminine charm. Brewing Tieguanyin or Shui Xian with water that is too cool fails to bring out their robust, masculine character.

2. Differences in the rate and speed of soluble matter extraction:

Higher water temperatures increase the rate and speed of extraction, while lower temperatures decrease them. This affects the control of tea concentration. With the same tea-to-water ratio, higher temperatures achieve the desired concentration faster, while lower temperatures take longer.

3. Control of bitterness and astringency:

Higher water temperatures intensify bitterness and astringency, while lower temperatures reduce them. Therefore, for teas that are too bitter, lowering the water temperature can improve the taste. For teas that are too astringent, reducing both the water temperature and steeping time can help. To achieve the desired concentration, the former requires increasing the amount of tea or extending the steeping time, while the latter requires increasing the amount of tea.

The appropriate water temperature for brewing different teas to achieve high-quality tea can be divided into three categories:

1. Low temperature (70°C–80°C):

Used for brewing green teas like Longjing and Biluochun, which contain tender buds.

2. Medium temperature (80°C–90°C):

Used for brewing lightly fermented oolongs like Baihao Oolong, mature-leaf green teas like Guapian, and lightly withered white teas (e.g., Baihao Yinzhen) and black teas.

3. High temperature (90°C–100°C):

Used for brewing heavily fermented oolongs like Pouchong, Dongding, Tieguanyin, Shui Xian, Da Hong Pao, Bai Ji Guan, Shui Xian, Oolong, and Rougui, as well as post-fermented teas like Pu-erh. For these teas, those with tender leaves require lower temperatures, while those with mature leaves require higher temperatures. Among these oolongs, heavily roasted ones require higher temperatures, while lightly roasted ones require lower temperatures.

Should the water be boiled to 100°C and then cooled to the desired temperature, or heated directly to the desired temperature? This depends on whether the water needs sterilization or if high temperatures are required to reduce certain minerals and disinfectants. If so, boil the water to 100°C first, then cool it to the desired temperature. If not, heat it directly to the desired temperature. Over-boiling reduces the gas content in the water, which is detrimental to the release of aroma—this is the principle behind not over-boiling water.

Other factors affecting water temperature for brewing tea include:

1. Pre-warming the teapot:

Whether the teapot is pre-warmed with hot water before adding tea leaves affects the water temperature. Pouring hot water into an unwarmed teapot lowers the temperature by about 5°C. Therefore, if the teapot is not pre-warmed, the water temperature should be slightly higher, or the steeping time should be extended.

2. Rinsing the leaves:

Rinsing the leaves involves pouring hot water over them and immediately discarding it, then brewing again to obtain the first infusion for drinking. This process, called "rinsing" (not always necessary), allows the leaves to absorb heat and moisture, speeding up the extraction of soluble matter in the subsequent brew. Therefore, the steeping time for the first infusion after rinsing should be shortened.

[Note] For information on brewing and storing Pu-erh tea, you can contact the shopkeeper of Nanming Jiaren or add dydy600 (long press to copy) for exchange and learning.