750 grams sugar
25 grams citric or tartaric acid powder
Place the thinly sliced peel of 1 lemon in a food processor with 2 cups of the sugar and process until sugar is yellow and oily looking. Juice all 3 lemons and mix with the lemon sugar. Add the remaining sugar and citric acid and enough boiling water to make the volume up to 6 cups (1½ litres) of syrup. Cool and store in the fridge in a well sealed container. Serve well diluted with iced water.