lemon sorbet

1.5 pints of water
12 oz sugar
rind and juice of 4 lemons
2 egg whites

1. Pare thins strips of the lemon peel off, just the yellow surface, not down to the white. Add them to a pan containing the water. NB It's not clear to me whether it's better to squeeze the lemons first or later.
   
2. Add the sugar to the pan and heat gently until the sugar has dissolved.
3. Boil rapidly for about five minutes.
4. Remove from the heat and allow the syrup to cool.
5. Squeeze the juice from the lemons. Add it to the cooled syrup.
6. Strain the syrup into a suitable freezing box.
   
7. Add the egg whites (just as they are, not beaten).
8. Gently break up the egg whites with a fork to disperse them.
9. Place uncovered in the fast freeze section of the freezer.
   
10. About two or three hours later, check to see if it is mushy. Don't be too impatient: it needs to be really almost frozen.
11. Decant the mush into a large basin (chill this in the fridge first, especially in warm weather).
12. Whisk it until it's all white and frothy. In my view a hand rotary whisk may be better than an electric one.
    
13. Spoon the froth back into the ice cream box (you may need two), put on the lid and place it in the freezer. It will be ready in an hour or two.

This makes more than two litres in my experience.