30 to 40 minutes. The main ingredient of zongzi is glutinous rice, which is not easy to cook and takes a long time to heat, so it takes 30-40 minutes to cook zongzi in Xi 'an restaurant. Zongzi, a steamed food made by wrapping glutinous rice with Zongzi leaves, is one of the traditional festival foods in China. Zongzi, as one of the traditional foods with the deepest historical and cultural accumulation in China, is widely spread.