Elderflower Cordial time

My daughter and son in law have pink elderflower bushes in their garden and this year, they are laden with flowers. This called for an elderflower cordial making session. After about eight attempts at finding the citric acid needed to make the cordial, they found some in Tesco.
I am lucky enough to have been given a bottle of it. I decanted it into an M&S gin liqueur bottle which I had for Christmas. The bottle lights up, which is very cool. Love the colour.