1. Prepare sour plum soup ingredients.
2. Pour all the ingredients except rock sugar into the pot and add about 1 liter of water.
3. Bring to a boil on high fire.
4. Cover and reduce heat and cook slowly for 30 minutes.
5. Open the lid and add rock sugar and cook on medium heat until the rock sugar melts and then remove from heat.
6. You can enjoy after drying.
7. It tastes better when placed in the refrigerator.