I got the recipe from a search engine but it turned out to be River Cottage which is always a good place for these type if projects. I was starting with cold when I heated up the lemon and ginger so I also believe this helped to easy my symptoms.
Currently the ginger beer is sitting in a warm place in my kitchen and I can't help but watch it when I walk past, it's fermenting beautifully and almost looks like it is fizzing.
Once it is ready to drink I'll let you know how it tastes... Can't wait!!
DECEMBER 2013:
Sadly this wasn't as good as I would have hoped, the recipe wasn't so clear on how long I should leave it (and my local home brew sales man scared me by telling me I hadn't made cider I had made a bomb) so I left it for 3 months. When I tasted it for the first time it was too dry and didn't taste of anything so I added more sugar after a while this turned to alcohol after a peerie start and the next time I tasted it it was horrible, not even suitable for mulling.
Next plan is to try a kit!!