Other citrus fruits can be used for this cordial recipe. This version is not hot water bath processed in the recipe but I always do this in the baby bottle steriliser for small bottles of produce and if it is a larger bottle I use a deep pan and fill up to the neck bring to the boil and then process for about 30 minutes which takes all the air out. It is the air that makes the produce go off so the hot water bath processing in effect removes the air and provides a tight seal.
3 unwaxed lemons
900ml boiling water
850g white sugar - granulated or caster
30g citric acid or tartaric acid
With a potato peeler cut thick ribbons of rind from the fruit leaving the pith behind but if you do manage to take some of the pith it can be scraped off with a sharp knife.
Place the rind into a heatproof bowl and pour over the boiling water stirring in the sugar until all the sugar has dissolved. Leave the mixture to cool and then add the juice from the lemons and the citric acid leaving everything to steep overnight. Make sure the bowl is covered.
Next day strain the rind away this is important as otherwise the syrup becomes bitter and decant into bottles.
At this stage you can hot water bottle process in the baby bottle steriliser for about 20 minutes after achieving the boil or for 30 minutes if using larger bottles after coming to the boil; or just store in the fridge for up to a month or store it in cartons in the freezer.
Serve the cordial a little in a glass diluted with still or sparkling water.