- In a small saucepan, bring 1 cup (250 ml) of the cranberry juice and the sugar to a boil, stirring until the sugar has completely dissolved. Remove from the heat. Add the remaining cranberry juice (3 cups/750 ml).
- In a large airtight container, combine the cranberry juice mixture, vodka, triple sec and lime juice. Cover and freeze for about 8 hours or until the mixture is firm.
- In a food processor, purée until smooth or scrape into icy crystals with a fork. Spoon the slush into glasses. Keep the remaining slush in an airtight container.