Iced Lemonade (Limon Granizado)

Wash and grate the rind of 1 of the lemons.
Place the grated lemon grind, water and sugar in a pan and heat slowly for about 10 mins remove from the heat and set a side to cool.
Squeeze the 6 lemons and sieve the juice into a separate container.
Sieve the cooled water, sugar and lemon rind and mix with the lemon juice and place in a container for freezing and place in the freezer.
Remove from the freezer and stir - repeat this process every hour for about 4 hours, until frozen, but not frozen solid.