1. Place blueberries and water in a
medium saucepan and bring to a boil.
2. Let mixture simmer for 15 minutes.
Cool.
3. Pour into a fine-mesh sieve
over a large bowl and let drain.
4. Stir
so that you get all the juice from the
berries.
5. Discard pulp.
6. Transfer
juice to a medium pot and add sugar
and lime juice.
7. Stir and bring to a boil.
8. Let mixture simmer for 5 minutes.
9.
Cool and mix with soda water and ice.
Keeps for 1 week, chilled.