finished spirit has eggy smell

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monkeydust
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finished spirit has eggy smell

Post by monkeydust » Mon Jan 26, 2009 3:29 am

Hi. Anybody have any ideas on why a carbon filtered spirit could produce a faint eggy aroma I have distiled a few batches now and this happened on 3 occasions. The 1st after adding a flavouring and most recently just as a plain vodka. It seams to gain this slight eggy aroma only after being filtered and left a while in glass bottles.

I posted this on another forum, but it appears to be something new, though someone did say about shaking up the finished spirit in the bottle and letting it then settle with the top off. any help is welcome

Hawke
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Re: finished spirit has eggy smell

Post by Hawke » Mon Jan 26, 2009 5:00 am

Eggy smell is some form of sulfer compound. Could be from your water, or could be in the charcoal. Have never had to filter anything I've made. (Of course my senses aren't very keen either)
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big worm
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Re: finished spirit has eggy smell

Post by big worm » Mon Jan 26, 2009 6:29 am

airing out with a coffee filter for a few days could help.
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brewmaker1
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Re: finished spirit has eggy smell

Post by brewmaker1 » Mon Jan 26, 2009 6:51 am

What's your still made of?
Do you have copper in the vapor path?
How do you clean your carbon?
What kind of water?

Hack
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Re: finished spirit has eggy smell

Post by Hack » Mon Jan 26, 2009 9:13 am

I read somewhere, but can't remember where, that you need to be careful of the kind of carbon you use for filtering. I seem to remember that some carbon is a petroleum byproduct, or something like that, and will impart nasty smells and tastes to your hooch.

Eggy smell is usually associated with sulphur. Making sure you have some copper in your vapor path will help if the smell is coming from your hooch.

Also, there is much deeply spiritual and religous advice on the forum here about how to make spirits that don't need carbon filtered. Ultimately, that is what I would recommend. It's not any real trouble to do, and actually saves work in the long run.

Dnderhead
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Re: finished spirit has eggy smell

Post by Dnderhead » Mon Jan 26, 2009 9:24 am

Stone carbon is made of coal "baked" to remove the softer parts, there's other carbons as coconut etc ,if you insist on using
if you are going to use "stone carbon" let it air out and rinse it good.

Hack
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Re: finished spirit has eggy smell

Post by Hack » Mon Jan 26, 2009 9:27 am

I think it was the stone carbon I was thinking of.

monkeydust
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Re: finished spirit has eggy smell

Post by monkeydust » Mon Jan 26, 2009 11:36 am

thanks for all helpful advice. I'm using a table top still :oops: sorry too all you die hard, make your own pot stillers. No i dont use any copper in the still and this is something i was wondering about. I do have some copper joints that i could put in, but! and here's the thing, surely ALL my finished spirit would have this eggy aroma, not just an odd bottle? I will do my next batch using these. Water I use to dilute is shop bought spring water. The carbon is in the form of a cartridge you screw into a filter kit that came with the still, but I will be looking at making my own, as it don't look up to much and someone has suggested actualy adding some activated carbon into my spirit for a time and filtering after

pHneutral
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Re: finished spirit has eggy smell

Post by pHneutral » Mon Jan 26, 2009 12:53 pm

I'm not an experienced distiller of alcohol, but I know a bit about chemistry..

Not necessarily all of your spirits would have sulfur compounds in them.. you're dealing with a huge number of variables:

1) No copper
2) Water supply
3) Carbon source
4) sugars used
5) fermentation conditions

All of these can vary from batch to batch (except the copper)

Copper gets rid of all of these troubles because it eliminates sulfur compounds in the distillate while you are taking it off (as does silver). If you don't have copper, the sulfur could be coming from anywhere. If you run a ferment hot and fast, and use more MgSO4 than needed, that could cause it as well. Lots of possibilities, and it would be hard to track them down.

Thiols (organic sulfur compounds) are incredibly smelly.. just a microscopic amount will result in that smell (thiophane is used in parts per million to scent propane and methane gas so you know there is a leak). They can be formed with sulfur and an organic acid and/or alcohol with heat, just like in your column. There is more to it than that, but that's a poetic way to look at it. You could try running an aquarium airstone through your finished spirit for a few hours to see if that knocks them down, but that will knock down flavor compounds as well.

rad14701
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Re: finished spirit has eggy smell

Post by rad14701 » Mon Jan 26, 2009 3:15 pm

The fact that you're using a "table top still" leads me to believe that you're probably using Turbo yeast and trying to push for a high ABV wash... If this is indeed the case, pushing for high ABV using Turbo yeast is the problem... Off smells and tastes aren't uncommon with this scenario...

olddog
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Re: finished spirit has eggy smell

Post by olddog » Mon Jan 26, 2009 3:24 pm

I totally agree with RAD, I been down the same path myself, I tried all sorts of filtering methods, a Z filter with granular carbon is about the best, but even then I used to either double or tripple filter to get rid of this, and yes I was using Turbo yeast. I have just completed the first ferment and distill using UJSM and the result is first class with no filtering required.
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Usge
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Re: finished spirit has eggy smell

Post by Usge » Mon Jan 26, 2009 7:29 pm

Culled from the excellent book "Brew Chemistry 101" which has entire chapter on different smells, chemistry and their causes in brewing (pertains to beer but well can be applied to what we do):

Sulfurlike/Rotten Egg/Burning match:
Off Flavor
Smell and taste of rotten eggs or a burning match (hydrogen sulfide)

Source
Small amounts of hydrogen sulfide are a natural product of yeast fermentation (in particular, metabolism of the amino acids methionine and cysteine).
However, the small amount of hydrogen sulfide produced by this process won't normally be noticed in beer. Additionally, a large amount of this hydrogen sulfide is removed during fermentation by "scrubbing" effect of rising CO2 bubbles.

Excess hydrogen sulfide that would cause a noticeable off flavor is almost always caused by a bacterial infection.

Increased fermentation temperature can increase this off flavor. Larger sulfer-containing molecules can also produce powerful off flavors, most giving rotten egg or skunky smells and tastes to beer.

To Avoid
Establish and maintain sanitary and sterile brewing conditions. Maintain proper fermentation temps.

Given the smell is faint, and that such compounds are inherent to yeast fermentation, I think also Turbo yeasts could be part of the problem as well. But the others are also worth checking out.

monkeydust
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Re: finished spirit has eggy smell

Post by monkeydust » Tue Jan 27, 2009 1:47 am

wow, thank you all very much! to think goverments wish to censor the net! 8)

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