Sciencemadness Discussion Board

Preparing ethanol from a sugar wash treated with Sodium carbonate

JohnnyBuckminster - 16-6-2022 at 03:10

A low wine, i.e. distillate from a sugar wash*, contains several different organic compounds of which one is EtOH. The challenge to prepare pure EtOH, i.e. Vodka, by distillation is to achieve good separation between organic compounds with similar boiling points.

On several sites across the internet, it is suggested to treat the low wine with sodium carbonate, Na2CO3·10H2O. They claim that this significantly helps to isolate the ethanol in the distillation process, but no one seems to understand why.

Does anyone here understand how sodium carbonate, Na2CO3, a base with pKa 10.33, can help with the isolation of EtOH from a low wine that probably contains a mixture of higher alcohols, ketones, aldehydes, and carboxylic acids?

I have got some information that this is more than just the state of the protonation of carboxyl groups etc., but I don't understand what that could be.


*A sugar wash is nothing but a fermentation done on a solution of sugar and nutritions, with no fruit etc. added. After a first distillation, to reduce the volume by removing water, the distillate is called a low wine, as far as I understand...

Mateo_swe - 16-6-2022 at 03:40

Is the ethanol produced meant for drinking, ie. vodka?
If you make the fermentation with just common sugar and "turbo yeast" avaliable at brewery stores you will get very little other alcohols and byproducts.
Just throw away the first distillate that comes over (that boils at lower temps) and you will be fine as long you clean the ethanol with some active carbon.
The ethanol produced will be very good if you use good quality active carbon.
If the ethanol is for chemical uses and need to be very pure i would destill it, clean it with active carbon and then distill again.

I never used fruits, grain and other things for the fermentation and it might produce more other alcoholes and byproducts.
So i have no experience of this, maybe your sodium carbonate treatment works.
I´m also intrested what other have to say about this.

JohnnyBuckminster - 16-6-2022 at 04:24

The sugar wash I'm referring to is prepared with table sugar and a common brand of TurboYeast and intended for drinking. Using active carbon is absolutely necessary for the prodcut to be drinkable.

In an attempt to produce high-quality Vodka I have tried a few different distillation techniques, for example, carefully distilling the low wine through a 100 cm vigreux column did not manage to isolate the EtOH. Also, a column with 6 bubble plates did not deliver much better results. All distillates require purification through active carbon of high quality, and still, my colleagues have no problem identifying my product in a blind test with commercial brands of Vodka. They get it 100% right every time. This is disappointing.

So I'm researching ways to improve the quality, and came across sodium carbonate. I have not tried this as I would like to understand the logic behind this suggestion.

Mateo_swe - 16-6-2022 at 05:00

Hmm, i have made much vodka in the past and im getting a quality where it tastes almost nothing and then a warmth in the chest, much, much better that store bought vodka.
But i use an all stainless distillation rig that takes 25L of fermented sugar/turbo yeast liquid.
It has built in electrical heating and on top is a stainless steel column, about 1 meter tall, 8cm wide, filled with small ceramic rings.
On the very top is a themometer showing and a small pipe leading downward to the condenser, all stainless steel.
The distillation process is self regulating and i just plug it in, throw away the fore-run and collect the rest, stopping when dripping gets very slow.
With one of these distilation setup´s its very easy to get good drinking ethanol but i have often heard about people having problems with chemical distillation setups ie. made of glass.
With my setup the most important thing is the quality of the active carbon.
If using a good active carbon the vodka gets very good.
Maybe someone knows how to get good ethanol with smaller glass distillation setups.
I find it strange that a 100cm vigreaux column cant separate the ethanol, maybe try with an cromatography column filled with glass beads.

JohnnyBuckminster - 16-6-2022 at 06:00

Mateo_swe, when you prepare the sugar wash, do you find that the concentration sugar at start, and that the pH and temperature during the fermentation are important parameters?

Mateo_swe - 16-6-2022 at 06:15

No, i just mix them and keep indoors in the boiler room where its slightly warmer.
I just dump 6kg of sugar in a 25L pail with roomtemp or slightly warmer water, mix and add the yeast, mix again and i just put the pail in our boiler room where its a few degrees warmer than roomtemp.
I dont have any bubler tube on the pail as there is too much gases evolving so i simply place the screw-on lid on top of the opening with a small gap to let the gases out.
It ferments and when the bubbeling stops its ready for the distiller.

Fery - 16-6-2022 at 07:34

Na2CO3 could hydrolyze esters like ethyl acetate or convert organic acids into their salts and reduce them in the distillate.

unionised - 16-6-2022 at 10:19

The alkaline conditions also promote converting aldehydes into yellow tarry stuff which isn't volatile

wg48temp9 - 17-6-2022 at 09:39

Quote: Originally posted by Mateo_swe  
No, i just mix them and keep indoors in the boiler room where its slightly warmer.
I just dump 6kg of sugar in a 25L pail with roomtemp or slightly warmer water, mix and add the yeast, mix again and i just put the pail in our boiler room where its a few degrees warmer than roomtemp.
I dont have any bubler tube on the pail as there is too much gases evolving so i simply place the screw-on lid on top of the opening with a small gap to let the gases out.
It ferments and when the bubbeling stops its ready for the distiller.


It sounds as if you are distilling with yeast in the liquid that will give the alcohol a terrible flavour. You need to let the yeast settle completely and only distill the clear liquid.

arkoma - 20-6-2022 at 06:40

Never used any carbon. I use an all glass rig and I have found that copper in contact with the steam is essential. my product, which put food on my table for over a year, had hardly ANY discernable smell or "flavor" at 55% EtOH.

Copper "chore boy" brand scrubbers work great packed in the column.

Fery - 20-6-2022 at 20:08

Copper removes organosulfur side products as arkoma wrote.