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 minutes, then 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 every hour or so and stir - repeat this process several times until almost frozen (but not solid).
When it´s almost frozen but not solid serve in tall glasses with a straw.