Using a stand mixer with a whip attachment or a handheld with single whip, beat the boiled juice for about 2 minutes. It will become foamy and doubled up in size. Add 2 cups of powdered sugar and whip for 2 minutes. Add the rest of the sugar 1 cup at a time whipping 1 min each time. Add in the vanilla. Whip until shiny and glossy and stiff peaks form when you lift the whip out of the mixture.