Hi,
Maybe this might be a strange question but i'm wondering what exactly the ginger bug is. Are those only the ginger parts (that have been fed with water and suger) or are thos the ginger parts including (some of) the water?
For kefir it's abvious to me, the grains should be used. With sourdough it's obviously everything, while it can't be splitted of course but for the ginger i'm not sure.
Till now, when making some ginger beer, i've used both ginger parts and water and that worked okay.