This week, in preparation for making the first batch of elderflower cordial of the season, I read up a bit on the process, and I'm happy to say I finally understand the role of citric acid in the recipe. If you have a look at the comments on this very informative blog post, 'The Elderflower Man' explains exactly why it is so important. The other thing I hadn't realised is that it can be difficult to find citric acid. I buy mine from an independent grocery shop in Totnes called The Happy Apple, but I understand it is often available in chemists, and sometimes from larger chain grocery stores. I have made elderflower cordial without citric acid, and I wouldn't recommend it. The resulting cordial is not only far too sweet, but it lacks that refreshing tartness that enhances the elderflower flavour so beautifully.
Here's the recipe I use (no idea where it came from, as I first used it about 16 years ago!):
yield: approximately 3 70cL wine bottles
75g citric acid
1 orange, zested and sliced
1 lemon, zested and sliced
1.2 litres water
When I am ready to make the cordial, I prepare my flowers by snipping off as much of the stem as possible and giving them a quick sluice in a bowl of water to remove any bugs. The Elderflower Man says you shouldn't wash them because it is the pollen that imparts the most flavour, but unless you are picking flowers from your own garden you might be happier giving yours a quick dip. I certainly haven't noticed the flavour to be any less full than commercially prepared cordial.
(gratuitous, self-indulgent, arty-farty photo)