Soak kokum in two cups of lukewarm water for ten to fifteen minutes. Mash kokum and strain its pulp.
Boil sugar, kokum pulp, salt and cumin powder for two to three minutes. Add a little water while boiling. Take off the heat, cool the syrup and store in a refrigerator.
While serving, put a little kokum syrup in a glass. Add cold water as needed, mix well and serve chilled.