Yeast Doesn't Fly

[HansB]

I think he was making the same point I did, that it gets on the wheat via the air. It may not fly, but it certainly gets blown around by the wind.

I missed that! Too early.   

[SlackWaterPizza]

Peter,

I'm happy that there are people doing the research into sourdough cultures and bacteria. I think that there is still a lot that we don't know, which keeps this pursuit interesting.

hb

""people's  doing the research into sourdough cultures and bacteria.""

exactly, that's why im doing my lil test now to solve for my self how true/false it is...
i started my Ischia SD Starter yesterday, and to keep it clean i sterilized very old flour so i didnt have to worry about contaminants....

i started with and will be feeding it AP (old, very old) that i put in the oven at 250f and left it for 40 min then let it cool down to 190f for about 1 1/2 hours then jared.
4 cups of de-yeasted, de-molded and de-fungied feeding flour..
lol, (i dont want to add any yeasts beside the unavoidably airborne stuff til i get a fully working Starter going!) to it so ill do the same cooking on the HW and Cuputo from time to time...
kept below 266f so i didnt denature the proteins....
Boiled Well Water, and kept my fingers crossed...

well it took off great so i guess i didnt kill the cooked flour..
so as i was doing this i said to myslef, self, nows the perfect time to do this simple and easy test...
i have 40g out side in an big wide tupperware with no lid... sitting on the porch..
in a week ill add 40g W and at the same time take 40g from the closed cooked feeding flour and start a match jar, and to be funner ill do a jar with the HW i got a month ago and the last one from a 55lbs cuputo blue i just got still unopened in the shipping box Original packing not a repak....

i statred my Ischia.... Working Great...
soon ill start just to see and compare...
1. the porch "air yeast on the wind" on cooked/cleaned flour
2. the jar'ed clean/cooked feed flour
3. the reg store bag HW
4. the middle of the bag cuputo
After the Ischia is going full and in frige land doezzzing, a week or so, ill start theses and do them all the same...
i think
1. "who knows what will grow from it"
2. starial..... wont do a thing...
3. should work just fine
4. should work just fine

damm ill have 5 starters if i do this and i still have a another culture in the frige..
i wont be keeping them much long at all unless i get a really good kicker outa one of them..

science at its finest..

Slack...

[Timpanogos Slim]

I'm sure it doesn't "fly" per se but wild yeast is everywhere, and gets around somehow.

For example, it's suspected that lager yeast originated in Argentina, and made it to europe long before any europeans made it to south america.

https://www.science.org/content/article/lager-beers-mystery-yeast

[wotavidone]

I'll throw a comment in.
In terms of industrial ventilation, a distinction is made between fumes and dusts.
The USEPA doesn't have a regulatory definition, but describes fume as "an airborne dispersion of small solid particles created by condensation from the gaseous state in distinction to a gas or vapor. Fumes arise from heating solids such as lead".
Around 2011 or so, I was capturing fumes from our lead heating processes and looking at them with a scanning electron microscope.
The fume particles from heating lead are little hollow spheres, always less than 50um in diameter.
Mostly, they were less than 10um.
We learned to think of these fumes as gases. i.e. so small that the moved in flowing air as a gas would, they didn't exit the moving air at bends in the pipework due to centrifugal forces, like a larger dust particle tends to do, etc.
They drifted away in clouds, rather than settle, as larger dust particles do. They would coagulate in low wind conditions and settle eventually of course, but it could be a scarily long way from the source.
Showing a newbie how to distinguish visually between steam (water vapour) and "metallurgical steam" (fume) was a routine thing.
What's this got to do with yeast?
Well, yeast cells look like little spheres, and are typically 3-4 um in diameter, ranging up to 40um in diameter.
I betcha they do "fly", regardless of what the article says, in the sense that although they may not actually float like a 1um microbe spore, they probably blow around in fairly low velocity air currents.