The color of roast duck can be brightened by using maltose water to turn it into jujube red. The method of making maltose water is as follows:

Preparation materials: barley, shelled barley, and glutinous rice.

1. Clean the barley and place it in a cool place.

2. In about 4-6 days, barley germ will appear.

3. Add the crushed malt to the glutinous rice and mix evenly. Leave to ferment in a warm place for 6-8 hours.

4. The fermented food is as shown in the picture.

5. Use a clean cloth bag to filter. It is recommended to filter twice.

6. This is filtered, off-white like rice soup.

7. Bring to a boil over high heat, then bring to a boil over low heat.