1. Ingredients: 450 grams of grapes.

2. Excipients: 150 grams of maltose.

3. Ingredients: 80 grams of fine sugar, 150 ml of water.

4. Peel and remove the seeds from the washed grapes. Place the skins and pulp in separate bowls for later use.

5. Put the grape skins into an acid-resistant pot (such as a stainless steel pot), add water and bring to a boil over medium heat, then reduce the heat to low and continue to cook until the juice turns purple.

6. Take out the grape skins and squeeze out the juice.

7. Put the grape pulp into the pot.

8. Pour the juice over high heat and bring to a boil.

9. Turn to low heat, add maltose and continue to cook. You must stir continuously with a wooden ladle while cooking.

10. After the maltose is completely dissolved, add fine sugar and continue to stir until the sauce becomes thick.

11. Pay attention to remove the floating foam when cooking.

12. Put it into a pre-sterilized glass, cool it to 70 or 80 degrees, and put it in the refrigerator.