One pound of glutinous rice requires 30 rice dumpling leaves.

Reed leaves are the most common Zong leaf material. Legend has it that after Qu Yuan threw himself into the Miluo River, the rice dumplings thrown into the river were made of seasonal reed leaves.

In the mountainous areas of East my country and Southeast China, Ruo bamboo leaves are often used as rice dumpling leaves. Ma bamboo leaves from Fujian, Guangdong, and Guangxi, and osmanthus bamboo leaves from Taiwan are also commonly used materials for making rice dumpling leaves.

Unscrupulous merchants use chemical raw materials to turn rice dumpling leaves green:

Reed leaves and bamboo leaves are mostly used for rice dumplings on the market. The emerald green color of the rice dumpling leaves does not mean that the rice dumplings are fresh, but may pose a safety hazard. He pointed out that the green color of rice dumpling leaves mainly comes from chlorophyll, but chlorophyll is a very unstable pigment. When rice dumpling leaves are affected by high temperature and oxygen, their color will turn yellow and brown.

After the rice dumplings are transported and stored, it is difficult for the rice dumpling leaves to remain fresh and green when they meet consumers; after steaming and cooking, it is even more difficult for the rice dumpling leaves to remain green. In order to cater to consumers' preference for bright green rice dumpling leaves, some merchants may use other means to prevent the leaves from turning yellow. For example, some unscrupulous merchants used industrial copper sulfate and industrial copper chloride to soak the rice dumpling leaves.

Reference for the above content:

People's Daily Online - Northern rice dumplings are fragrant and sweet, southern rice dumplings are salty and fresh, and rice dumplings with green leaves hide hidden dangers