Introduction
Oolong tea, known as “wulong” in Chinese, occupies a unique position among the six major tea categories due to its semi‑fermented nature, which typically ranges from 20 % to 70 % oxidation. This intermediate processing gives oolong a rich spectrum of flavors—from the fresh, green‑like notes of lightly oxidized varieties such as Baozhong to the deep, roasted, and honey‑laden profiles of heavily oxidized types like Da Hong Pao. Because quality can vary dramatically across this spectrum, China has established a national standard that defines clear grade boundaries based on both sensory evaluation and measurable physicochemical indices. The following article explains the GB/T 18745‑2002 standard for oolong tea, outlines the four official grades, details the criteria used to distinguish them, and offers practical guidance for enthusiasts and beginners seeking to identify and appreciate each level.
Historical Background of Oolong Tea Grading
The practice of grading tea in China dates back to the Tang dynasty, when Lu Yu’s The Classic of Tea (Chajing) described the importance of leaf shape, color, and aroma in assessing quality. However, formal grading systems for oolong tea only