dogstar- anyone is entitled to their own definition of what the ginger beer plant (GBP) is but the OP is referring to the keffir-like grains that are essentially polysaccharide conglomerates made by the weird range of bacteria and yeast that they host. they slowly ferment the ginger beer precursor that you put them into, adding flavor and allowing the fermentation to continue on a bit to give carbonation after they are removed. they are great because the flavors are unique, they don't ferment very quickly, leaving you with a sweet drink, and there is not much cloudy yeast to clear out of suspension. you just strain them out and put them to rest, or add to your next batch. they are also really cool to watch, as the booger-like beads float up and down in the drink while they are active. GBP makes a very different drink from a yeast-fermented ginger beer, usually so low alcohol to be essentially non-alcoholic (~0.5-1% abv), worth a try if that's what you want and you can find the plant. i got mine from the uk link listed above- gingerbeerplant.net so i can vouch for them. in various discussions in the 'soda' forum of HBT there have been (...uninformed..) people saying that that's not GBP but keffir grains and that they know the difference, blah blah. i suggest ignoring that type of argument.