- In a food processor, purée the strawberries and grape juice concentrate. Pour into a container and seal. Freeze for about 6 hours or overnight.
- With a fork, scrape the frozen strawberry mixture until it turns slushy.
- Spoon part of the mixture into a chilled tall glass. Top up with still or carbonated water. Add about 5 ml (1 teaspoon) grenadine and stir. Serve immediately with a big straw.