I promised to post my recipe for elderflower cordial and as Spring seems to be leaping ahead here in the Loire, there is no time to waste. I normally make double the quantity given and that just about keeps us going for a year (assuming we can control our post vintage frenzy of drinking it every day for a couple of weeks). You can buy citric acid in most chemists in the UK - not quite as easy to source here in France if you're not involved in wine, but you can order it at the pharmacie and they will get it in for you.
You will need
21 Elderflower heads - fresh and in full flower
2 Sliced lemons
2 Kilos of sugar
100g Citric acid
1.5L Boiling water
Pour boiling water over the other ingredients until the sugar dissolves (I normally use a bucket). That's it - as simple as that. Cover with a clean tea towel and put somewhere cool. Give it a good stir every day and leave it for between 5 and 7 days. Strain it thoroughly before bottling.
I find that half bottles are good for this - keep some full bottles for yourself and use the halves to give to other people.