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Author: Subject: Cleaning Homemade Ethanol
Daffodile
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[*] posted on 16-11-2016 at 11:37
Cleaning Homemade Ethanol


I make all my own Ethanol through fermentation and repeated distillation, but often it still comtains traces of yeast. Can this just be removed with activated carbon? Or will I need anything else?
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DraconicAcid
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[*] posted on 16-11-2016 at 12:08


Traces of yeast after distillation? I find that hard to believe.



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[*] posted on 16-11-2016 at 12:37


If it really has yeast in the condensate, your distillation is bad. Too hot/boiling too hard, cooling coil inlet too close to liquid surface, overfilled pot are a few thoughts.



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[*] posted on 16-11-2016 at 13:25


Distilling ethanol from a yeasty mix just needs, er, distilling.

The heat kills off the yeast, so mostly ethanol & water make it out of the pot.

For anyone actually trying this, just follow the instructions at homedistiller.com

Plenty of very useful references there.




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wg48
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[*] posted on 16-11-2016 at 13:51


If you distil a solution contain significant amounts yeast it gives the product a different flavour than that produced by distilling a clear solution even if no whole yeast reaches the product.

In effect your steam distilling essential oil from the yeast LOL That may be a flavour you like but probably not.
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DraconicAcid
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[*] posted on 16-11-2016 at 13:51


Quote: Originally posted by aga  
The heat kills off the yeast, so mostly ethanol & water make it out of the pot.

Doesn't matter if the heat kills it or not- living cells generally don't evaporate.




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aga
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[*] posted on 16-11-2016 at 13:55


Some bits do come over, hence the need to re-distill after a 'stripping' run.

A low-alcohol yeasty mix tends to be a highly complex mixture of ethanol and loads of other OC.




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[*] posted on 16-11-2016 at 16:16


I thought it was just denatured proteins being carried over suspended in droplets of vapour. The first distillation is done 25m separation of condenser from liquid, second is 15cm. I do it this two step copper ->glass way to save time.
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[*] posted on 16-11-2016 at 19:47


You could just filter and re-distill it. That should get rid of any solids.

I prefer to use a biofilter approach with my kidneys to remediate the ethanol.
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[*] posted on 16-11-2016 at 20:27


Usually I wouldn't care, but I've been making awesome vodka recently, and yeast gives it a strange taste before multiple distillations. I wanted to find a denaturing chemical or otherwise that can give me complete precipitation of yeast I can remove before the first distillation.
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[*] posted on 16-11-2016 at 22:06


Slightly different, but in the past I have distilled the yeast wash with glassware and achieved a foul smelling distillate. Rather than discard or redistill multiple times, adding a SMALL quantity of KMnO4 with stirring to the cooled distillate and allowing to react fully (and until no "rotten egg" or sickly smell remains) before redistillation has removed almost all of the nasty smells.
I suspect this to be due to the permanganate oxidising aldehydes and sulfurous compounds to higher boiling and less "aromatic" compounds (including some ethanol), but have no evidence of course.

This approach is great for a very neutral spirit (or laboratory reagent) but would likely destroy any nuanced aromas you may be trying to create.

With other batches which require the flavours and aromas to be conserved, I have used freeze distillation. This method consists of freezing the entire wash in a container with a neck (much like a large wine bottle), inverting the bottle over a secondary container, and allowing the bottle to defrost and drip into the secondary container. In this process, a third of the original liquid is collected until the mostly-solid wash is discarded, most of the yeast particulate being trapped in the ice-water mixture. The largest portion of the alcohol and volatile organics are concentrated in the secondary container, and upon allowing the yeast to settle and pouring off the clear supernatant liquor, distillation yields a spirit with little to no yeasty-ness while maintaining much of the desired aroma and flavour.




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[*] posted on 16-11-2016 at 22:50


At a local bodega yesterday i learned that they sample their fermentations regularly, then stop the yeast action at the point they consider the flavour/ethanol content to be 'best'.

Previously i thought that sodium metabisulphite was added to achieve this, but no.

The yeast is normally killed by adding ethanol to bring it to around 15%.

For a cleaner flavour and 'true' ethanol content they chill the mash down to -2 C for a few days instead !

In either case there is no extra flavour added (e.g. sulphites) and the dead yeast precipitates out as 'lees'.

Their dry Moscatel "Seco Sobre Lias Finas" is awesome.

http://www.bodegasbentomiz.com




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[*] posted on 17-11-2016 at 02:23


Distillation rarely cleans a bad ferment. Sulphur smells are the result of low nutrition for the yeast. Worse is when a high sugar content wort (i.e. going for a high ethanol fermentation) stressed the yeast and the high ethanol being produced just acts as a solvent for the dead yeast sucking out nasty flavours. Best vodka flavour comes from low sugar and content good nutrition. Getting the yeast to settle I recommend aluminium sulphate and then egg white. Rack off the yeast and add carbon and wax pellets. Should give a very clean wort.
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[*] posted on 17-11-2016 at 09:47


Hmm I'll try filtering once, adding Aluminum Sulfate, filtering, adding Sodium Carbonate, and filtering one last time before distillation. Thanks guys.
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[*] posted on 17-11-2016 at 14:27


When distilling EtOH from whatever foul fermentation products I've used, I pack my claisen with a bunch of curli-cues of 10 gauge copper wire. Grabs the sulfur nasties. I haven't achieved azeo yet--gotten close. These massive injuries I received put it all on hold. However, I have reached 90% EtOH that no has discernible smell at all from various dodgy fermentables.



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[*] posted on 17-11-2016 at 19:15


The first distillation should be acidic.
This reduces ammonia compounds in the distillate.
Copper in the column will reduce sulfur compounds.
Getting it to azeotropic will leave ethyl acetate in larger quantities.
Sodium hydroxide solution added will destroy the acetate.
Then redistillation to the azeotrope will be very pure.
Dilution with distilled water and running it through activated carbon
will polish it. Then a final distillation.

Achieving azeotropic is a function of column height and reflux.
Otherwise it requires multiple distillations.
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[*] posted on 18-11-2016 at 11:33


4.5' column on a 14 gallon pot seems to work well. 180+ proof first pass then if it's not azo on the second I can't tell the difference on the hygrometer.
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[*] posted on 18-11-2016 at 12:06


What's a hygrometer?


EDIT: arkoma below:

Thanks, glad to see you back.

[Edited on 19-11-2016 by Maroboduus]

[Edited on 19-11-2016 by Maroboduus]
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[*] posted on 18-11-2016 at 15:57


Had to have been a typo:

HYDROmeter--measures the densities of liquids wikipedia

HYGROmeter--measures relative humidity




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[*] posted on 19-11-2016 at 00:52


Quote: Originally posted by Lithium  
Slightly different, but in the past I have distilled the yeast wash with glassware and achieved a foul smelling distillate. Rather than discard or redistill multiple times, adding a SMALL quantity of KMnO4 with stirring to the cooled distillate and allowing to react fully (and until no "rotten egg" or sickly smell remains) before redistillation has removed almost all of the nasty smells.
I suspect this to be due to the permanganate oxidising aldehydes and sulfurous compounds to higher boiling and less "aromatic" compounds (including some ethanol), but have no evidence of course.

This approach is great for a very neutral spirit (or laboratory reagent) but would likely destroy any nuanced aromas you may be trying to create.

With other batches which require the flavours and aromas to be conserved, I have used freeze distillation. This method consists of freezing the entire wash in a container with a neck (much like a large wine bottle), inverting the bottle over a secondary container, and allowing the bottle to defrost and drip into the secondary container. In this process, a third of the original liquid is collected until the mostly-solid wash is discarded, most of the yeast particulate being trapped in the ice-water mixture. The largest portion of the alcohol and volatile organics are concentrated in the secondary container, and upon allowing the yeast to settle and pouring off the clear supernatant liquor, distillation yields a spirit with little to no yeasty-ness while maintaining much of the desired aroma and flavour.



I've made sugar alcohol and there's always some yeast-like odor which i can't get rid of even after several distillation. Is this the smell of aldehyde or sulfur-like odor. will a redistillation using copper column get rid of the smell...or do I need to use kmn04 or something. thanks.
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[*] posted on 19-11-2016 at 01:25


Try some activated carbon before distillation, these "yeasty" flavors are volatile organics. Trough it in, let stand over night and decant/filter before distillation.

Often when you see "yeast extract" on the ingredients list of instant noodles or other dried instant stuff, they are the flavors. For example Unilever uses a specific yeast strain which tastes like chicken when grown in a specific growth medium and after been given a heat shock. Marmite is another famous example of strong odour/taste.
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