Secrets of sourdough

Pffft. They're not secrets.

They're not even a mystery.

Not said: The guy sticks his hand in the dough up to his arms and now his arms are loaded with bacteria and yeast. He touches his hair and now his hair is loaded with bacteria and yeast. He touches his eyebrow and likewise.

He goes to the bathroom and now the yeast is spread to his nether-regions and crawls up the hair on his chest and down his legs.

The bacteria and yeast are airborne and they coat every single service, every crack, every corner in his entire bakery. Exactly like a cheesemaker's cave. You couldn't get rid of the bacteria if you tried using bleach spray or high temperature spray. It will will keep coming back.

Like the inside of your refrigerator. 

The only way to clean it out is buy a new refrigerator. The organisms get onto every single surface, every nook and cranny, every wire, throughout the insulating material.

I'm imagining all this. 

Because you will notice even though you bleach out the trays and drawers you still cannot store anything in there very long, once your refrigerator becomes seasoned by storing cheese, and yogurt, and other fermented foods. The refrigerator is permeated with living organisms that turn everything sour quite quickly. It's nearly impossible to keep things air tight.

A portion of the first comment: 

There's one detail I disagree with you on, however.  When you create a starter, you're growing wild yeast in the flour itself, not wild yeast captured from the air.  There are a few wild yeast and bacteria in the air, yes, but there's nothing for the yeast (or lactobacillus) to eat in the air; wild yeast can't reproduce in the air.  There will be millions and millions of yeast in the flour itself, because wheat has the carbohydrate yeast need to live.  (Wild yeast also colonize fruit, for the same reason, and that's why you could make hard cider, or wine, or bread, without adding commercial yeast.)  The density of the yeast population in wheat, compared to the scarcity of yeast in the air, means that every starter you make, you're growing yeast that was in the flour (not captured from the air).

Okay, Pal. 

Where do you think the yeast on the grain in the fields came from?

The yeast and bacteria in the air that we breathe is not scarce. 

And you can prove this yourself. 

You will find when you collect yeast from the air for a week using flour slurry (that has the yeast in the flour) and race its cultivation with slurry straight from the flour that the clean flour slurry cultivation wins the race. Not the slurry with organisms collected from air.

Why?

The air-collection cultivation is having a war between its components as they multiply. They're having a race themselves for domination. Cultures within the culture are winning and losing and all that takes time.

Meanwhile the purer culture garnered from the single wheat field already had this war and it populations are settled. 

So the sourdough cultured straight from wheat slurry is the culture of wherever the wheat grain was grown. 

Sometimes that's a combination of wheat fields depending on the mill that the flour came from. Mills mix grains to get a predetermined protein level. You can never get straight answers from large mills. Their process is too complicated to provide simple answers. 

I know this because I asked them. I called mills and interrogated. They cannot answer simple questions because nothing about them is simple. 

Smaller local mills are different.

However, if you collect airborne yeast and bacteria in slurry (that has its own yeast and bacteria) then more and more airborne organisms get shoved into your sample. 

High winds are great for collecting. But they also dry out the collection. The yeast and bacteria are suspended in the air. The guy is right, there is nothing for them to feed on. The organisms are unhappily closed up. They've created a protective shell around themselves. They've divided into single dna sets and formed a shell around their dna and they were carried high into the atmosphere that freezes them. They're whipped along jet streams and carried clear across the planet, over oceans, through forest, through the fur of animals, whipping through foliage, and landing splat right into your slurry where they get started dissolving their protective shells and connecting with their corresponding dna types and creating full sets of double dna packages and even fuller double sets of double dna packages for as long as their environment allows them. 

They're brought into your slurry by wind, by rain, by snow, by tornados, and hurricanes, by light breezes, and by simple air pressure shifts. 

The longer you collect, the more you keep refreshing the slurry, the more you keep adding water and stirring, the longer you keep the collection mode going then the more seriously complex your starter culture will be. Far more complex than than the culture already on the flour. 

I proved this over and over and over and over and over.

Keep thinking over and over, because I did this a LOT of times. 

The last time was three weeks collecting during a highly active weather season, and boy, is that culture ever strong. It is the strongest culture that I've collected. It's fast as regular yeast that designed over decades to be fast and extremely farty. 

It's a beautiful culture that I named "Denver" but its source is actually several surrounding states. 

This airborne quality is why Oregon trail starter is qualitatively different from all others, why the Pacific northwest has such unique sourdough, why the Hawaiian types are so incredibly unique, it's why International Sourdough exists and why all their samples are completely different.