Step 1

Place barley in a sieve. Rinse under running water until water runs clear then place in a saucepan with lemon rind and 6 cups of water. Bring to the boil over medium heat. Simmer for 10 minutes then strain mixture into a heatproof bowl, discarding barley.

Step 2

Add sugar to bowl. Stir to dissolve then stir in lemon juice. Pour into bottles and refrigerate until chilled.