Hi Charlotte
I've not looked too closely at the PH of elderflower wine until this year. I've made it for a few years and last years was a bit too sweet for my liking. The acidity was all obtained from Lemon juice so it was likely to be variable being natural.
The acidity will affect how the wine feels in your mouth and how dry it seems and I guess getting the balance of sugar, acidity and tannin right is part of the fun.
Previously the recipe that I followed uses the juice and zest from 2 unwaxed lemons per 5 litres. This year I am going to use the zest and juice of three lemons but this year I will make a note of the PH!
You won't go far wrong with this level of acidity; fiddle about with it, make two smaller batches and make changes between them -whatever you do have fun doing it and enjoy the process.
I'm off now to do my first elderflower pick of the year to make elderflower cordial and 'champagne', next week I'll pick elderflowers for wine and the week after for elderflower cider. There will still be enough flowers to produce elderberries for my autumn wine and the trees left dripping in fruit for the birds!
Elder a brilliant way to get into home brewing and you can't really go too far wrong if you look after your sanitisation.