Hi, I've maintained and used a sourdough starter many years of my life, and I've tried different methods of making the stater. For a while, I would make my bread and then pinch a piece of it off (a "levain") and let that function as my sourdough starter for the next loaf.

More recently, I feed a cup of sourdough starter with flour and water each day, and after a few days when it gets old enough, I start a new one using a small amount of the sourdough as a "seed" and discard the rest (usually I make bread with it).

My question is about the seed - if a sourdough starter has a variety of microbes, the way I seed the next starter might have an impact, it's a form of selection.

Since they are microbes, I assume there are many of them in the sourdough and I don't need much to get "enough" of a sample to keep a healthy culture going - I just stir a spoon in the old sourdough, then use that same spoon (with the little bit of sourdough stuck to the spoon) to stir the new sourdough's flour and water together, and that's it.

But I keep thinking about how this might be a kind of selection - and I was wondering if there is a significant difference in, for example, a levain method of pinching off a piece of the whole and the microbial sampling that has vs the sampling from just not cleaning off the spoon when stirring the old and then the new.

I would imagine the levain has a greater likelihood of all the microbes being present, while a single spoonful might constitute a more narrow subset of microbes? Or maybe the microbes are distributed evenly enough in the sourdough that a spoonful represents as broad a sample as a pinched off piece?

I haven't noticed any obvious, practical differences in how the starter is made, but I'm wondering if a theoretical, significant difference exists.

I guess some of this paranoia comes from thinking about Zeno's paradox, the 100 prisoner problem, and the Monty Hall problem.

A levain seems more likely to contain a small amount of each kind of microbe (since the whole is incorporated and then mixed well before being divided into a part) than the approach of starting a new starter from a single spoonful (which necessarily selects only a subset first from the whole - a subset which may or may not be as evenly distributed as from a levain).

In practice this probably makes no difference, but maybe there could be minor ways a spoon would preference some kinds of microbes over others (maybe if the spoon were made of silver, for example, the microbes that survive contact with the silver would be more likely to carry on to future generations?).

Anyway, thoughts? (Other than about my mental fitness, lol.)