Take the juice and skin of 10 lemons (or like we like it 5 lemons and 5 oranges):
Add to this 500ml sugar, 1 tablespoon of Epsom Salts and 1 Tablespoon of Tartaric Acid and 2 litres of boiling water. Stir til sugar is dissolved.
Allow the concentrate to cool and then strain into 2 large jugs. Pour a little over ice or pour cold water into it 1:1. Nothing to beat this flavour and with ice after a hot day in the garden...mmmmh!