Ginger bug is the term for the wild yeast and (generally lacto) bacteria found on ginger. To get some you grate up some (non-irradiated) ginger root, combine it with some sugar and water in a jar and wait. I was reading in Sandor Katz’s The Art of Fermentation that the same thing could be done with Turmeric and Galangal root. I’d never seen turmeric in root form for sale anywhere, but I happened to notice some the other day at my local highfalutin grocery store. It was pretty expensive so I just bought a tiny piece. I brought it home, grated it up, added a few tablespoons of sugar, a bit of yeast nutrient and some warmish water. A day or so later it was bubbling away rather vigorously!
I’m assuming I have some combination of yeast and lacto bacteria here. It smells like intense turmeric so it’s hard to tell if it is getting sour at all. I’m going to let it go for a week or so while I try to decide what I should do with it. I was thinking I’d like to make a turmeric ‘beer’ like a ginger beer, but the root is pretty expensive. Maybe I’ll just try a gallon batch for starters and see how it is.