Soak the apricots in 2.25 litres/4 pints cold water for 8 hours or overnight. Drain the water into a large pan and add the finely grated zest of the lemons, their juice and the sugar. Place over a medium heat and stir until the sugar has dissolved. Bring to the boil and simmer for 15 minutes.
Add the apricots and simmer gently for about 45 minutes until the apricots are just tender, but