I dig this sort of thing for the same reasons you do. This kind of network-based storage of useful organisms has personal significance for me, since my extended family has been passing around and maintaining a yogurt culture for 40 years now, originating in my grandmother’s kitchen, if not earlier. (I don’t know where it came from, but I doubt it was brought over from the “old country” since she fled there at the point of a bayonet.) We Armenians purport to have “invented” yogurt in the olden days, but I suspect this claim is apocryphal.

The twist I like to put on this type of story is to consider whether it isn’t the organisms manipulating us to give them a good home, rather than the other way around. The satisfaction of human desires (gourmet, aesthetic, or pharmacological) has to be one of the most successful evolutionary strategies nature has invented.

As for the stability of cultures over time and space, I have wondered about that myself. I too have heard the claim about San Francisco sourdough cultures being impossible to maintain outside of the Bay Area, though it seems that the jury is still out as to its validity. Frank Sugihara, one of the researchers who first characterized the biology of SF sourdough (a symbiotic association of the acid-loving yeast Candida milleri and the acid-producing bacterium Lactobacillus sanfranciscensis)says that such cultures remain stable no matter what the environment. However, many bakers claim that the bacteria in a transplanted culture will be replaced over time by local flora. There is a nice summary of the debate here: http://www.discover.com/issues/sep-03/departments/featscienceof/

My experience (so far, at least) is that the SF sourdough culture I have is pretty stable. I can’t say for sure which bacterial species I have in there, but there is no question that particular culture is much more acidic, more “SF like”, than the Italian one I’ve been maintaining alongside it.

I love this story, for two reasons. First, the "Botany of Desire" reason. If you go to the web-site, you’ll see that there are volunteer "starter keepers". These are presumably people who have recieved the starter, continue to maintain it, and are willing to send it to someone in response to a request. Does that structure sound familiar? Does it sound a tad like BitTorrent? Well, the analogy is not quite sound, since a single request for starter is not servered by several "starter keepers" each sending a fraction of the required starter. But, I love the idea of a YeastTorrent. So, it’s not really BitTorrent. But it is the internet! There is a long tradition of exchanging starters among bakers, and in this way, yeast have developed, along with their human collaboorators, a robust, fault-tolerant, highly redundant network for their own replication. Imagine some catastrophic event that somehow killed all of the starter west of the Mississippi. It would not take long at all for "starter keepers" in the east to fully repopulate the larders of the west. Robust, fault tolerant, networked. Sorry Al, it looks like yeast invented the net first.

The second reason is really a question. I have always heard that San Francisco sourdough starters will only grow in the unique conditions of San Francisco, and that when they are sent elsewhere they actually become the "local" starter over time. Is that true? It would suggest, of course, that the "starter helpers" may not really be sending anything close to the original, and that any person who gets the origianl will end up with their own local variant after some time. So, I wonder if there is any sense to getting exotic, but non-local starters? I’m no expert on this, but I’ve always liked the mystique that every local sourdough bread really does have a unique local flavor.