1. Peel off the old skin of buckwheat head and wash it.
2. Then add cold water and salt to soak for one day.
3. Add rock sugar and white vinegar to the pot and boil it into sweet and sour juice. It is best not to cook in a metal container.
4. After that, take the buckwheat head out of the pickle jar.
5. Then, add sweet and sour juice.
6. Finally, seal it and eat it next week.