1. Soak the prunes in lightly salted water for 1 hour, rinse under running water;

2. Put them in a pot (a pot that can be steamed) pour sugar and salt all over them, mix well and marinate for more than 2 hours;

3. Put the pots together in a steamer (my pots are taller. If I can't put the lid on after putting it on the steam curtain, I put the basin directly in the water, which also works well). Cover the pot, bring the pot to a boil, and steam over medium-low heat for 25 minutes;

4. While still hot, pour the prunes and juice concentrate into a dry, oil- and water-free bottle. Tighten the lids and use when cool. (Bottling while hot will keep longer, and refrigeration will keep it for 10 days or more, but eat it as soon as you open the lid.

5. For longer-term storage, wait until cool before bottling and then close the lid. Place the bottle in a pot with water and cook on low heat for 15 minutes. By this time the bottle has become vacuumed and will keep for a long time. The bottles should be previously used canning bottles that won't burst;

6. To drink, cup 2~3 prunes with a spoon, then add 2 tablespoons of juice concentrate and pour it into cold boiled water, purified water or ice water to dilute. Add some ice cubes will be more refreshing and delicious.