This cordial is very easy to make if you have fresh Elderflowers on hand. I found it in Darina Allen's book "Forgotten Skills of Cooking", which is an excellent book and you may be familiar with her Ballymaloe Cookery School in Cork.
The cordial is delicious in prosecco or white wine, soaked into cake or used as a topping over ice cream. Our Elderflowers are just starting to bloom here on the farm. Yields 4.5 cups
10 Elderflower heads
2 1/2 cups water
4 cups sugar
1 3/4 ounces citric acid
1 lemon, sliced thick
You will need 10 Elderflower heads for this recipe. Once you have those pull the flowers off the heads, trying to avoid pulling too much of the stem with it, and place in a bowl. The leaves, stems and unripe berries of elderberry bushes contain toxins so that is why you remove all but the flowers, buds, and small stems.
In a saucepan that can comfortably hold 4.5 cups of fluid, mix water and sugar over medium heat until the sugar is dissolved. Remove the sugar + water mixture from heat and add the sliced lemons and elderflowers. Stir in the citric acid. Now we wait. Cover the pan and let sit at least 4 hours, but ideally overnight for more intense Elderflower flavor.
Strain the mixture through a fine mesh strainer and then bottle. Don't throw out the lemons! Instead, put them in a plastic bag and into the freezer. When you make a drink with your cordial, throw in a few of these beautiful slices of lemon to float on top.
You'll need to keep the cordial refrigerated. It's best fresh, but I've had mine for a year and it's still very good.