Poll: Source of Variation Among Starters

Thanks Mini,

I could answer by own question by doing a fairly invovled experiment.  But I'd rather just be baking bread :-)  So I thought I'd throw it out as kind of a collective thought/experience experiment.  Here's the basis of my query:

After a starter has been maintained for a while and attains some measure of refresh-to-refresh stability, it is likely to have become dominated by a fairly small number of different organisms (to be biological:  X-number of different species of yeast and bacteria, and Y-number of different genotypes (different 'strains') within those species of yeast and bacteria.)  It starts out as a lively competition with probably a fairly small number of winners, more than likely just one per species (gets messy when one considers that the various innocula can be having sex and trading genes, but let's leave that aside).  The field of competitors from which the winners in a 'stable' starter utlimately emerge had to have been introduced into the system from somewhere.  My question is, primarily where?  We have a boatload of potential innoculum sources to choose from.  Flour isn't exactly sterile, so there's a likely source of innoculum.  Neither is the water, juice, vessel, hands, tools or air.

For an experimental approach, consider this scenario:  I initiate three rye starters, one with water,  one with pineapple juice and one with grapefruit juice, all other things being equal (my hands, my water, my utensils, my jars, my house air, my dogs' dander).  Each develops a respiring microbial population that I proceed to maintain on the same rye+water feeding regime.  How different will they be from one another after a few months?

On the other hand, if I initiate separate starters, one with rye, one with spelt, one with whole wheat and one with corn meal, with all other factors being equal (pineaple juice, my hands, my tools, etc.), how different would they be, microbially, from one another?

To cover the possibility that it is just a stochastic crap shoot as to which bugs dominate and define the starter, we have to include the control of independently initiating a set of totally identical (in every way) starters and ask how different they ultimately end up being from one another.  Dividing an existing stable starter four ways wouldn't ask the question, because each is already dominated by single dominant bug(s) and any pretender to the throne would have a seemingly insurmountable challenge of overthrowing the dictator(s).

I recognize that actually differentiating the products of each of these tests becomes an experimental challenge in and of itself.  Smell tests?  An old school microbiologist would try to streak out, isolate and ID all the bugs.   A new school microbiologist would do metagenomics, if she could afford it.

Another factor might also be that some grain species' flours support a narrower range of microorganisms than others.  If that were the case, then perhaps we'd see that, "most rye starters are similar to one another" but "starters born and raised on all purpose wheat flour can be as different as night and day".

Microbial community ecology of sourdough starters -- in particular the succession that must surely occur as a new starter is initiated --  is really fascinating.

tdb

Thanks Jim,

But "picking up" a copy of Kulp and Lorenz requires some heavy lifting @ $150+.  I'll check the library for sure.

Thanks again!

tdb