Introduction:To brew Phoenix Dancong with its signature high aroma and lingering throat sensation, water selection actually matters more than brewing technique. This article explores from a scientific perspective how TDS, water hardness, and pH influence the sweetness, freshness, and clarity of the tea liquor, and compares the effects of soft and hard water on oolong tea flavors — helping you easily master the secret to brewing the perfect Phoenix Dancong with the right water.
To brew a truly remarkable pot of Phoenix Dancong, water choice is often more critical than technique. As early as in Lu Yu’s Classic of Tea during the Tang Dynasty, spring water was ranked as the top choice for brewing tea, with emphasis placed on “mountain spring water, slowly flowing, collected in a stone pool, yields the sweetest taste.” Modern science explains through TDS (total dissolved solids), water hardness, and pH how different water qualities affect the color, aroma, and flavor of tea liquor. This article focuses on oolong teas such as Phoenix Dancong, using measured data and research to analyze why soft water better highlights the sweetness and vibrancy of the tea, while hard water may introduce astringency and scum on the surface — helping you find your ideal water for your favorite tea.
As far back as the 8th century, Lu Yu was extremely particular about water for brewing tea. He particularly praised mountain spring water, noting that “of all mountain waters, those that flow gently from milky springs and stone pools are the best,” emphasizing that the water flow should be slow and sourced from clean rock layers. Such water typically contains moderate minerals and offers a smooth taste. Ancient tea lovers were even willing to trek over mountains and ridges for good water — showing just how deeply water quality affects tea performance. However, there is still no absolute standard for what kind of water is best for brewing tea. Different tea types have varying preferences, and some even insist on matching a certain water’s “aroma” or origin with the tea leaves — all subjective and nuanced experiences.
Though opinions vary, modern scientific research provides clearer reference points. For example, based on recommendations from the Tea Association of the USA, suitable water standards for most tea types are generally: pH value between6 and 8, TDS (total dissolved solids) at50–150 ppm, and total hardness advised to be controlled around80 ppma certain range. Among these, experts commonly agree that within this range,softer water (i.e., low TDS and low hardness), is better able to bring out the layered complexity and delicate flavors of high-aroma oolong teas such as Phoenix Dancong.
One study conducted practical tests comparing various water types — including tap water (~200 ppm), bottled mineral water (~70 ppm), mountain spring water (~20 ppm), and purified water — for brewing multiple kinds of tea (Xu et al., 2017). The data showed that tea brewed with low-mineral water had a softer and more layered taste, with mountain spring water receiving the highest overall praise. In contrast, higher water hardness often led to increased astringency, reduced sweetness, and even suppression of the fresh vibrancy that tea should have.
Moreover, water hardness also directly affects the appearance of the tea liquor. When using high-hardness water, a layer of “scum” often forms on the surface — a thin film created by the combination of proteins in the tea leaves and minerals in the water. There may also appear what is known as “tea cream,” which refers to cloudy solids suspended or settled in cooled tea liquor. By comparison,tea brewed with low-hardness soft water is usually clearer and brighter, with a more subdued color, significantly less scum or cloudiness, resulting in a more visually pleasing overall presentation.
Besides mineral content, the pH of water is also a major factor influencing tea performance. Some experiments found that adjusting tap water’s pH down to around6using acidic substances can improve clarity and overall taste to some extent, approaching the performance of mountain spring water. However, even with well-adjusted pH, issues like astringency and sedimentation caused by high hardness remain difficult to completely eliminate. Other studies also indicate that tea types where catechins are the main flavor component — such as green tea — are more sensitive to mineral content in water. Compared to black tea, their taste and liquor color are more affected by water conditions.
Based on a synthesis of multiple studies and practical experience, if you wish to fully express the high aroma, sweetness, and throat feel of Phoenix Dancong, it is recommended to start withlow-mineral soft water— such as mountain spring water or appropriately filtered tap water — and observe the subtle changes in tea liquor under different water conditions. This way, not only will you gain a deeper understanding of your tea, but you’ll also appreciate the infinite wonders of the interplay between water and tea with each brew.
The above content is compiled by CoffeeHunters, a coffee news website.
