The Art of Brewing Tea: What You Need to Know About Tea Water

In Vietnamese tea culture, there is a saying: “Nhất thủy, nhị trà, tam bôi, tứ bình, ngũ quần anh” — which highlights the inseparable companionship between water and tea. In the art of tea brewing, water is always considered the most important element, much like a mother nurturing and perfecting her child. Since the quality of water directly affects the quality of a pot of tea, the art of tea brewing is also the art of selecting water. In this article, Chính Long will take tea enthusiasts into the world of the art of choosing water for tea.

“Sơn thủy thượng, giang thủy trung, tĩnh thủy hạ”
In The Classic of Tea (Trà Kinh) by Lu Yu — known as the Sage of Tea in China — he ranked the types of water used for brewing tea with the phrase: “Mountain water is best, river water is moderate, well water is the lowest.” For tea brewers, mountain spring water is considered the highest quality. Water from high mountain springs is always pure, absorbing the essence of nature — the mountains and forests. However, in tea brewing, this mountain spring water must be carefully selected, taken from gentle streams flowing over pebbles and stones.

Second on Lu Yu’s list is river water, and third is well water. Tea connoisseurs always value water that flows from mountain or hill sources because of its purity, clearness, and full concentration of natural essence. River water should be taken from the middle of the upper reaches where the flow is calm and steady. Well water should come from wells located on mountains or hills, especially those at quiet temple sites far from urban noise. From this, we see that the art of tea brewing is meticulous even in distinguishing water sources.

Water from high mountain streams creates delicious tea.

The quality of water in tea brewing
In tea brewing, the water quality must meet the following standards: soft water, clear and transparent, free from turbidity, fresh taste, low temperature, and sourced from a clean environment.

What’s the difference between hard water and soft water?
Hard water contains a high mineral content, especially calcium ions (Ca²⁺) and magnesium ions (Mg²⁺). When boiled, hard water tends to produce white scale deposits. Moreover, using hard water to brew tea often causes the tea to develop a scum on the surface. The mineral content reacts strongly with tea polyphenols, making the tea taste stronger and darker in color.

Unlike hard water, soft water is natural water or rainwater, with much lower ion content. Thus, when boiled, it does not produce scale deposits. The softness of water is maintained in basins with hard, impermeable rock. This is why the art of tea brewing requires water from rivers and streams flowing through rocks, or from wells in limestone areas, etc.

Differences in mineral content between hard and soft water.

How does water quality affect tea?
It is said that choosing water is an art in tea brewing because of its delicacy and attention to detail. Different water qualities produce different tea flavors. Tea brewers must understand these effects to always ensure the quality of the brewed tea. Water with high hardness and alkalinity will diminish tea’s flavor. Acidic water makes the tea lose its color and taste sour. Alkaline water darkens the tea and gives it a bitter taste. Water with a high salt content causes salty tea, and water with much iron or manganese darkens the tea and creates a fishy smell.

When observing the water color, one should avoid water that is green (indicating algae), yellow (due to iron and manganese), or turbid (due to colloids and iron). The quality of water directly influences the tea’s flavor and color. The hidden qualities of tea leaves are awakened by high-quality water.

Preferred water in Vietnamese tea culture
In Vietnamese tea culture, it is traditionally believed that vũ thủy — rainwater — is the best water for brewing good tea. Rainwater tastes sweet, is neutral in nature, non-toxic, beneficial for qi (energy), and cooling to the body. Brewing tea with rainwater not only yields a perfect flavor but also has health benefits. Elders advise not to collect water from the first rains of early summer but rather from the third or fourth rains to obtain clean, fresh water. Traditional rainwater collection tools were various, such as tanks or wells, which had to be cleaned thoroughly to avoid dirt or algae.

Besides rainwater, the art of tea also values lộ thủy — dew drops — which are clear, sweet, and non-toxic. Tea artisans often collect dew drops early in the morning on bamboo leaves or stems in early autumn to capture this pure water, still infused with the breath of nature. Đông lộ is another popular type of water in folk culture, collected like dew but during winter. Đông lộ is sweet, cold in nature, non-toxic, and used to brew tea that cools the body. Additionally, mountain people use tuyết thủy — snow water — to make good tea. When collecting snow water, one must carefully remove the top 15–20 cm of snow to get pure, dust-free water. Another tip when selecting water for tea is to use water sourced from tea-growing regions to bring out unique tea flavors.

Dew drops on bamboo leaves carry the pure essence of early morning.

When learning about tea and the steps to make a delicious cup, we realize the indispensable importance of water and the meticulous effort required to select the right water. Therefore, the tea brewer is an artist, and every step in choosing water and brewing is part of the art of tea.