OK Here's the recipe I use
100g fresh ginger
400g sugar
1tsp Cream of Tartar
4 lemons
5g dried yeast
5 litres boiling water
In a sterilized bucket chop the 4 lemons. Add the sugar, cream of tartar and ginger.
Pour on the 5 litres of boiling water.
leave to cool and then sprinkle dried yeast on the surface. Any dried yeast will do. I use bakers yeast.
Cover and leave overnight or about 24 hours.
Strain, bottle and store for at least 2 days.
Leave a gap at the top of your bottles and don't forget to release the pressure every so often to avoid bursting bottles.
I bottle mine in 500ml plastic sparkling water bottles and fill them to just above where the straight part of the bottle ends.
When loosening the caps to let off the pressure and also when serving, it is best to do it slowly and gradually.
This ginger beer is a "live" fermentation so it will continue to ferment and build up pressure after bottling.
Do not worry about any sediment in the bottom, this is just a natural result of fermentation.
The flavour improves given a few more days in the bottle.
Regards Paul