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1
Put all the ingredients except rock sugar and lemon into a pot, add water and boil over high heat for 20-30 minutes. -
2
Add rock sugar and cook until the rock sugar melts. -
3
Add a little black coffee powder (mainly for coloring, don’t worry about the coffee taste.) -
4
Turn off the heat, filter out all the ingredients, and let it dry until it is no longer hot to the touch. Add soda water.