Why ethanol vapor doesn't get trapped in bread dough, while CO2 does?

  • #1
lost captain
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TL;DR Summary
Why ethanol vapor doesn't get trapped in bread dough, like CO2 ? They are both gases in the oven but one escapes the complex gluten structure while the other get traped inside
In ethanol fermetation and especially when baking a bread: "Yeast organisms consume sugars in the dough and produce ethanol and carbon dioxide as waste products. The carbon dioxide forms bubbles in the dough, expanding it to a foam."
We learn that ethanol leaves the bread, it escapes the gluten structure, it vaporizes but CO2 gets trapped inside. Why is that?
They are both in gas form(inside the oven), they are both small molecules, they are both in the same oven temperature hence their kinetic energy will be the same.
 
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  • #2
lost captain said:
TL;DR Summary: Why ethanol vapor doesn't get trapped in bread dough, like CO2 ? They are both gases in the oven but one escapes the complex gluten structure while the other get traped inside

In ethanol fermetation and especially when baking a bread: "Yeast organisms consume sugars in the dough and produce ethanol and carbon dioxide as waste products. The carbon dioxide forms bubbles in the dough, expanding it to a foam."
We learn that ethanol leaves the bread, it escapes the gluten structure, it vaporizes but CO2 gets trapped inside. Why is that?
They are both in gas form(inside the oven), they are both small molecules, they are both in the same oven temperature hence their kinetic energy will be the same.
Hi Lost Captain
The full quote from Wiki includes an alcoholic content of bread. ( the high value from the reference, rather than a range )
" Ethanol fermentation causes bread dough to rise. Yeast organisms consume sugars in the dough and produce ethanol and carbon dioxide as waste products. The carbon dioxide forms bubbles in the dough, expanding it to a foam. Less than 2% ethanol remains after baking"

I see nothing of
lost captain said:
We learn that ethanol leaves the bread,
so it might be worthwhile to explain where you got that idea from.

Hint:
At room temperature, is CO2 a gas or a liquid?
At room temperature, is ethanol a gas or a liquid?
Is there any water in the bread, and if so, how might that effect the formation of the bubbles, be it either from CO2 or ethanol being the main culprit responsible for the leavening?
 
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  • #3
256bits said:
so it might be worthwhile to explain where you got that idea from.
Most of the ethanol vaporizes, since the amount left on the bread is pretty less than the ethanol that was produced.
That's why i said ethanol leaves the bread.
(Of course i searched that online before making that statement, my source wasn't any scientific paper, just a typical google search)
So compared to the CO2 that is being traped inside the gluten structure, why the same doesn't happen to the ethanol vapor?
256bits said:
At room temperature, is CO2 a gas or a liquid?
At room temperature, is ethanol a gas or a liquid?
At room temperature CO2 is gas and ethanol is a liquid. But still even before puting the bread in the oven as long as the ethanol fermentation has started, CO2 gas gets trapped inside while ethanol vaporizes
In the oven they are both gases, shouldn't ethanol also be responsible for the creation of bubbles inside the dough, bubbles because of ethanol vapor.

256bits said:
Is there any water in the bread, and if so, how might that effect the formation of the bubbles,
Sure there is water, but i cant make the connection...maybe ethanol is diluted in water while CO2 isn't?


Also thank you very much for taking the time to reply.🙇‍♂️
 
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  • #4
Speculation:
At r.t, ethanol is a liquid and CO2 is a gas. Ethanol as it is formed is chemically mixed with water in the dough, whereas CO2 is physically trapped in the dough. Upon baking, the ethanol is therefore free to evaporate along with the water, whereas trapped pockets of CO2 will increase in size and set as the bread bakes. You'll also notice that when you bake bread, there is some bubbling in the dough, so not all CO2 is trapped.

Just a guess.
 
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