Snadger - I have seen this in Sainsburys I think - can't remember the name of the company but these are with the other cordials and they come in ginger beer, elderflower and another one methinks. If you want a recipe for ginger beer, ginger wine and there is one for "kentish winter cordial" I can post them for you. Guess if you replaced the fruit in the cordial recipe with ginger it would work.
DDL
PS I also have a recipe for beetroot beer! not sure about that one at all! LOL