Black Gulaman Serves 4. 1 can grass jelly (black) 6 cups water 4 cups dark brown sugar 1 teaspoon vanilla extract 750 ml cold water To make the arnibal (syrup): Boil six cups of water in a saucepan. When it comes to boil, add four cups of brown sugar. Stir the mixture continously until the sugar dissolved. While stirring, simmer until the mixture thickens. To make the drink: Add about one and a half cup of arnibal into 750ml of cold (in a pitcher). Stir well. Cut grass jelly into small thin cubes and add into the pitcher. Best served cold, without ice.