Yttrium2
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products produced through yeast fermentation
whats been produced since sugar to alcohol, and who studies , or knows how to deal with producing products through yeast fermentation. Can other
microorganisms also
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j_sum1
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Ethanol and carbon dioxide are the main products. But this varies. Not all microorganisms metabolise the same way. And not all behave the same
under all conditions (availability of oxygen being one of the chief variables.)
Other products can include lactic acid, acetone, butyric acid, hydrogen gas and probably a bunch of other things. Then, given a but of oxidation you
can have acetaldehyde and acetic acid which then lead to a bunch of byproducts: esters included.
Of course in the world of fermentation it is not just sucrose that is used and then you have whole fields of possible products which give a variety of
flavours to your beverages.
Any yes, other organisms can be used for fermentation including some bacteria and various other non-yeast fungi.
Big field. I'm no expert. I'll shut up now.
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Ubya
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a few weeks ago i was intrested in butanol production using fermentation,
https://en.wikipedia.org/wiki/Acetone%E2%80%93butanol%E2%80%... this is just an idea of what can be done
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markx
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Even the most common bakers yeast fermentation of simple sugars produces a whole collection of different substances besides the ethanol and carbon
dioxide being the main components:
Acetone, methanol, aldehydes, ethyl acetate (also acetate esters of higher alcohols), amyl alcohols (pentanol isomers), furfural, organic
acids....just to name some.
The main problem is that one needs a very good fractionating column to separate just some of them out the main stew and it is quite a complicated mix.
For example a quite reasonably pure ethyl acetate fraction can be separated from the heads of a distillation run.
Methanol content is usually very low (but remarkable in products that are fermented using apples).
Amyl alcohols can be separated from congener fraction (tails) and furfural from the very end of the tail fraction if grains are used as the source of
sugars. It is a lot of work and usually not worth doing on small scale, but for the fun of it I have separated the amyl alcohol fraction, concentrated
it by leaching out the residual water with a saturated brine and used it to produce a sample of amyl acetate. Quite a flavorful ester....smells of
pears, banana, and a whole lot of something else that I really can't place.
Exact science is a figment of imagination.......
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Yttrium2
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why does the yeast produce those compounds though?
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macckone
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Ethyl acetate is nearly impossible to separate from ethanol.
Ethyl acetate has a bp of 77C
Ethanol has a bp of 78C
Yes given enough reflux and enough runs you can get it out but it isn't easy. It is easier to decompose it with sodium carbonate or sodium hydroxide.
If you are making ethyl acetate, the usual method is absolute ethanol and acetic acid over sulfuric acid or sodium bisulfate at reflux with an acid
water scavenger (sulfuric acid acts as a scavenger).
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unionised
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Quote: Originally posted by macckone  | Ethyl acetate is nearly impossible to separate from ethanol.
Ethyl acetate has a bp of 77C
Ethanol has a bp of 78C
Yes given enough reflux and enough runs you can get it out but it isn't easy. It is easier to decompose it with sodium carbonate or sodium hydroxide.
If you are making ethyl acetate, the usual method is absolute ethanol and acetic acid over sulfuric acid or sodium bisulfate at reflux with an acid
water scavenger (sulfuric acid acts as a scavenger). |
The azeotrope boils at 71.8C
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Fulmen
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It's food. In the absence of oxygen they extract energy from converting sugars into other compounds.
We're not banging rocks together here. We know how to put a man back together.
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macckone
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Unionized, yes ethanol and ethyl acetate form an azetrope as well. But I can assure you that if you have significant ethyl acetate in your ethanol
the only way to get it out is by using sodium hydroxide or carbonate.
And it is undrinkable if there is too much ethyl acetate.
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