Add the water and sugar to a medium saucepan and stir on a low heat until dissolved. Continue to cook for a little longer (around 60 seconds).
Pour the sugar syrup into a large bowl and add the squeezed lemon juice.
Blend the raspberries in a food processor then pass through a fine strainer to get rid of the pips.
Combine the raspberries and sugar syrup then add to the fridge for at least 3 hours to cool.
Add to ice cream machine and churn as per manufacturer's instructions.
Scoop into an airtight container and freeze until hardened (3 hours).
