Chapter V · The Brewing · Section 1: A modern tea-science reading — reading “其水用山水上江水中井水下”

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Thesis

Read through modern tea science, “其水用山水上江水中井水下” is not a lab result but a set of variables: cultivar, soil, light and plucking standard.

Text

“For water: mountain spring is best, river water next, and well water lowest.”

Context

古人择水：山泉水最优，江水次之，井水最下。核心是"活"与"清"。

Evidence

• Collation: 各本一致。此句为全书最广为引用的择水标准，后世茶书多沿其说。
• Existing readings: 吴觉农指出：陆羽"山水上"之论影响千年，其内核是"活水为上"——山泉活水含氧高、杂质少；现代水质科学证实，矿物质适度、溶氧充足的活水确实更宜茶。

Analysis

Modern tea science would split “其水用山水上江水中井水下” into cultivar, soil, light and plucking variables. 吴觉农指出：陆羽"山水上"之论影响千年，其内核是"活水为上"——山泉活水含氧高、杂质少；现代水质科学证实，矿物质适度、溶氧充足的活水确实更宜茶。 They remain testable, but only with their conditions attached.

Conclusion

The section does not give a universal rule. It demonstrates a method: read the text, the annotation and the Tang context together before making a modern claim.

Source: The Classic of Tea, Chapter V · The Brewing, section 1; the original is in the public domain.

A maker reads “其水用山水上江水中井水下” through weather and soil first. 古人择水：山泉水最优，江水次之，井水最下。核心是"活"与"清"。 That is not far from how we judge a mountain and a picking window today.

The vessel is not background. 古人择水：山泉水最优，江水次之，井水最下。核心是"活"与"清"。 The same leaf in a different bowl, grinder or sieve changes aroma and texture; vessel and tea are defined together.

Water and fire magnify the difference. The same leaf at a higher temperature or a longer steep changes the sweet-bitter balance; the text only becomes operational at the brewing stage.