- In a small saucepan, bring 250 mL (1 cup) of cranberry juice and sugar to a boil. Stir until sugar is completely dissolved. Remove from heat.
- Add remaining cranberry juice (750 mL/3 cups).
- In a large airtight container, combine sweetened cranberry juice, vodka, triple sec and lime juice. Cover. Freeze for about 8 hours or until mixture is firm.
- In a food processor, puree frozen mixture until smooth or scrape surface with a fork and break up into crystals. Spoon slush into glasses.
- Store the rest in the freezer in an airtight container.