Step 1

Peel the rind off 2 lemons, taking care to get just the outer skin, no white pith (use a potato peeler).

Step 2

Place the peel and 2 cups of the sugar in a food processor and run the processor until the rind is really ground up and the sugar is yellow and oily looking. Tip into a large saucepan.

Step 3

Squeeze all 6 lemons and strain off to remove any pips. Mix the juice with the lemon sugar mixture in the saucepan and add the remaining sugar and the citric acid. Add the 3 litres of water and cook over a medium heat, stirring until the sugar dissolves.

Step 4

Cool, pour into clean bottles and store in the fridge.

Step 5

To serve, dilute with water – 1 part cordial to 3 or 4 parts water. To make fizzy lemonade, dilute with sparkling mineral water or soda water. For a party, try pink lemonade by adding a few drops of pink food colouring to the cordial. Dress up the glasses with fancy straws, ice cubes, slices of fruit and cocktail umbrellas or little plastic toys.

Step 6

Makes 3 litres of concentrated cordial.