Is it really vinegar or just sour ????
Elderberries are high in acid up to 14 gram per liter !!!!
This year I measured up to 8 gram per liter.
Last year was 14 gram !!!
So when making elderberry wine I use 3 to 4 kilo elderberries
dilluted with water to 10 liter.
Did you measure acidity ???
Vinegar does not just come to existance.
Campden surpresses the vinegar bacteria.
Vinegar bacteria need oxygen. So when a wine is fermenting
there will be a layer of CO2 on top of the wine and that will
inhibit vinegar bacteria.
Go and smell a vinegar bottle in the kitchen and compare that
to your wine. Even taste a bit. Then you can for sure tell
if it really is vinegar you are tasting and smelling, or that
the wine is just tart.
It would help if you could submit the recipe
you are using.
Luc