The first set of Longjing tea samples, which were classified according to national standards, was released in Hangzhou, Zhejiang province, on Monday.

The "Longjing Tea Sensory Grading Standard Sample" consists of tea leaves categorized into six levels based on the national standards released in 2008. They are the country's first standard samples and provide a direct and clear demonstration, according to Gong Shuying, a professor from the Tea Research Institute, Zhejiang University, the team behind the samples.

The Longjing tea grade is evaluated based on indicators such as the appearance of the tea leaves, the color of the tea soup, the aroma, the taste and the appearance of the tea leaves after brewing.

Longjing tea, a specialty of Zhejiang province, has a history of more than 1,000 years. The province has 73,300 hectares of tea gardens, and its production value exceeds 6.2 billion yuan ($856 million), according to provincial government data.