Add your sugar and water to a sauce pan and bring to a simmer, make sure you stir it until all of your sugar is completely dissolved.
Set your mix aside to cool completely and add a sprig of mint whilst it’s cooling.
Blitz your blackberries in a food processor and sieve. Remove and discard your mint sprig from the cooled syrup before adding your strained blackberries, juice and zest of a lemon to the syrup and combining the two.
Add your mix to an ice cream maker and churn until smooth. Add to serving dish or container and freeze overnight.