Cherry Soda Syrup

Dilute with sparkling water like a cordial. Use fresh or frozen cherries. If you can't get sweet cherries, use all sour (e.g. morello) and omit acid. There's a recipe for acid phosphate elsewhere on the site. If you don't want to make it, you could sub in citric acid but will have to play with the amount. Filtering is pretty important to stop the vanilla seeds forming nucleation sites and killing the fizz. The glycerine helps with head retention and helps the flavour coat your tongue. Store in fridge.