Long time lurker with a dozen or so batches under my belt.
Now this is no big deal but I have read over and over that that even at 95% distillate can have off tastes or smells because there's that 5% which can contain something other than water. I think this is incorrect given that most of the substances that we are trying to cut out are less dense than water wouldn't they actaully be part of the 95%. I mean if we had a theoretical mix of 50% ethanol and 50% methanol with no water we would get a reading of 100% but 50% is not ethanol.
As I said this doesn't really have any practical implications. Just saying.
Is it in the 5% or the 95%
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Re: Is it in the 5% or the 95%
Should be primarily in the 5% if cuts have been properly made... True, the 95% may have a bit of lingering heads and a bit of tails mixed in but if proper fractioning is taking place in the column they should be a very low portion of that 95%... The 5% is the everything else, not just water...
The only real way to know is to send samples for lab analysis, but samples from different runs would most likely yield different results... At least one of our members, perhaps The Chemist or manu de hanoi, has had samples tested...
The only real way to know is to send samples for lab analysis, but samples from different runs would most likely yield different results... At least one of our members, perhaps The Chemist or manu de hanoi, has had samples tested...
Re: Is it in the 5% or the 95%
Sorry Rad I don't think I made the point I was trying to make too clear. This isn't about making cuts but about how we assume that when we read our hydrometer that the 95% reading is pure ethanol and that the 5% is water and congeners but I think that the reading is 5% water and 95% ethanol and congeners.
In the example I used methanol due to it's almost identical density to ethanol. So a liter made up of 475ml of ethanol and 475ml of congeners and 50ml of water would read 95% but there is no way the 475ml of congeners is the other 5%.
In the example I used methanol due to it's almost identical density to ethanol. So a liter made up of 475ml of ethanol and 475ml of congeners and 50ml of water would read 95% but there is no way the 475ml of congeners is the other 5%.
Re: Is it in the 5% or the 95%
No, you were very clear in your first post as that is how I read into it... Perhaps I wasn't fully clear in that regard in my reply... There is always potential for "smearing", which is why I mentioned different lab results for different samples...
To clarify, as I see it, equal amounts of ethanol and congeners shouldn't read 95% if collecting at azeotrope... I think that is where our views differ...
To clarify, as I see it, equal amounts of ethanol and congeners shouldn't read 95% if collecting at azeotrope... I think that is where our views differ...
Re: Is it in the 5% or the 95%
Right, this isn't a "I have a problem or question" topic. It's more of a "I think we may be looking at it the wrong way" topic. I understand smearing but that is not what I am talking about. It's more about how we may be reading our hydrometers wrong.
Alright one more try for an example you buy a bottle of 95% isoproyl and you drop your hydrometer in it and get 95%. It's all congener and the other 5% is water.
Alright one more try for an example you buy a bottle of 95% isoproyl and you drop your hydrometer in it and get 95%. It's all congener and the other 5% is water.
Re: Is it in the 5% or the 95%
Hmmm... Let's look at it this way...
At azeotrope ethanol would read 95% @ 78C/172F... Agreed...??? However, if we took equal amounts of ethanol and methanol, for example, we could never collect 95% @ 78C/172F at purity... Why...??? Because the methanol will already be gone if we are achieving stabilized azeotropic purity... Methanol has a boiling point of ~65C/148F... Properly monitored distillation, using a thermometer and alcoholmeter, would assure that the methanol is virtually depleted before we hit our hearts temperature...
Now, if we were to merely collect by temperature alone then we might be fooled into collecting smeared distillate at a stable temperature while thinking it is at purity when it isn't...
Anyone...???
At azeotrope ethanol would read 95% @ 78C/172F... Agreed...??? However, if we took equal amounts of ethanol and methanol, for example, we could never collect 95% @ 78C/172F at purity... Why...??? Because the methanol will already be gone if we are achieving stabilized azeotropic purity... Methanol has a boiling point of ~65C/148F... Properly monitored distillation, using a thermometer and alcoholmeter, would assure that the methanol is virtually depleted before we hit our hearts temperature...
Now, if we were to merely collect by temperature alone then we might be fooled into collecting smeared distillate at a stable temperature while thinking it is at purity when it isn't...
Anyone...???
Re: Is it in the 5% or the 95%
You're right there, you can't put 50/50 methanol and ethanol in a still and collect it at 50/50. But, I'm not talking about running it through a still I'm talking about pouring 50/50 methanol/ethanol into your testing container and taking your hydrometer reading from that. It would read 100% but of course it would not be 100% ethanol.
Re: Is it in the 5% or the 95%
Do hobby stillers typically get interested in these kinds of excersizes? Certainly not for the sake of stilling with no means to an end.Bagasso wrote:You're right there, you can't put 50/50 methanol and ethanol in a still and collect it at 50/50. But, I'm not talking about running it through a still I'm talking about pouring 50/50 methanol/ethanol into your testing container and taking your hydrometer reading from that. It would read 100% but of course it would not be 100% ethanol.
What is the point????
And by BTW, good point Rad.
Trample the injured and hurdle the dead.
Re: Is it in the 5% or the 95%
Hi Bagasso, I think what you are saying is that there is a "soup" of molecules in the wash, and when the ethanol boils off it will drag some of the soup with it. That doesn't really happen because the alcohols are not separate in the wash, they form compounds with specific physical properties.
from wikipedia http://en.wikipedia.org/wiki/Azeotrope_(data" onclick="window.open(this.href);return false;" rel="nofollow)
Azeotropes of water, Boiling Point=100°C 2nd Component BP of comp. BP of mixture % by weight spef. grav with various alcohols
ethanol 78.4°C 78.1°C 95.5 0.804
methanol[3] 64.7°C No azeotrope
n-propanol 97.2°C 87.7°C 71.7 0.866
iso-propanol 82.5°C 80.4°C 87.9 0.818
n-butanol 117.8°C 92.4°C 55.5
sec-butanol 99.5°C 88.5°C 67.9 0.863
iso-butanol 108.0°C 90.0°C 70.0
tert-butanol 82.8°C 79.9°C 88.3
allyl alcohol 97.0°C 88.2°C 72.9 0.905
benzyl alcohol 205.2°C 99.9 9
So methanol does not form an azeotrope with water. so at 64.7 C it will ALL boil off
iso-propanol and water mixed for example will ONLY boil off at 80.4.
So its not the alcohols that boil off, its the mixture of alcohols and water that boil off.
Now some alcohols form azeotrope compounds with ethanol.
Azeotropes of ethanol, BP=78.4°C 2nd Component BP of comp. BP of mixture % by weight spef. grav with various esters
ethyl acetate 77.1°C 71.8°C 69.2 0.863
methyl acetate 57.0°C 56.9°C 97
ethyl nitrate 87.7°C 71.9°C 56
isopropyl acetate 88.4°C 76.8°C 47
But as you can see the boiling temps are all different.
So boiling them separates the compounds out.
Cheers
EDIT: This is a simplified explanation but I think it still holds.
from wikipedia http://en.wikipedia.org/wiki/Azeotrope_(data" onclick="window.open(this.href);return false;" rel="nofollow)
Azeotropes of water, Boiling Point=100°C 2nd Component BP of comp. BP of mixture % by weight spef. grav with various alcohols
ethanol 78.4°C 78.1°C 95.5 0.804
methanol[3] 64.7°C No azeotrope
n-propanol 97.2°C 87.7°C 71.7 0.866
iso-propanol 82.5°C 80.4°C 87.9 0.818
n-butanol 117.8°C 92.4°C 55.5
sec-butanol 99.5°C 88.5°C 67.9 0.863
iso-butanol 108.0°C 90.0°C 70.0
tert-butanol 82.8°C 79.9°C 88.3
allyl alcohol 97.0°C 88.2°C 72.9 0.905
benzyl alcohol 205.2°C 99.9 9
So methanol does not form an azeotrope with water. so at 64.7 C it will ALL boil off
iso-propanol and water mixed for example will ONLY boil off at 80.4.
So its not the alcohols that boil off, its the mixture of alcohols and water that boil off.
Now some alcohols form azeotrope compounds with ethanol.
Azeotropes of ethanol, BP=78.4°C 2nd Component BP of comp. BP of mixture % by weight spef. grav with various esters
ethyl acetate 77.1°C 71.8°C 69.2 0.863
methyl acetate 57.0°C 56.9°C 97
ethyl nitrate 87.7°C 71.9°C 56
isopropyl acetate 88.4°C 76.8°C 47
But as you can see the boiling temps are all different.
So boiling them separates the compounds out.
Cheers
EDIT: This is a simplified explanation but I think it still holds.
Last edited by plonker on Thu Jan 14, 2010 5:11 pm, edited 1 time in total.
Re: Is it in the 5% or the 95%
You are correct there. Methanol has a lower density than ethanol, so a hydrometer would not give an accurate reading for a mixed sample. a stilled sample would not be a 50/50 mix.
It is the very things that we think we know, that keep us from learning what we should know.
Valved Reflux, 3"x54" Bok 'mini', 2 liebig based pots and the 'Blockhead' 60K btu propane heat
Valved Reflux, 3"x54" Bok 'mini', 2 liebig based pots and the 'Blockhead' 60K btu propane heat
Re: Is it in the 5% or the 95%
We never do that so the point is somewhat moot... While the two alcohols may be nearly identical in weight our concern is boiling points... I just don't see where you're going with this... Please explain where this relates to an equalized fractioning still...Bagasso wrote:You're right there, you can't put 50/50 methanol and ethanol in a still and collect it at 50/50. But, I'm not talking about running it through a still I'm talking about pouring 50/50 methanol/ethanol into your testing container and taking your hydrometer reading from that. It would read 100% but of course it would not be 100% ethanol.
Re: Is it in the 5% or the 95%
The point was theoretical and to actually look at the "idea" offered on the forum quite often, that if you take distillate at 95% you have 5% water/congener and 95% ethanol when in fact you would have 5% water and 95% ethanol/congener. Now the type and amount of congener is what would give different vodkas different hints of flavor depending on the wash. So you may end up with 95% ethanol or 94.5% ethanol/.5% congeners or even 90% ethanol/5% congeners and that would be the reason why some distillate taken at 95% is clean while others have hints of flavor and others still have a flavor you can't get rid of (molasses).
Re: Is it in the 5% or the 95%
As I posted earlier, I dont think its the congeners in the product giving it flavor (well not in a fractionating column). Its water soluble flavorings that come across with the 5% water.
The whole point of what we do here is to eliminate the congeners as much as possible to make a better quality product.
Less congeners = less hangover
The whole point of what we do here is to eliminate the congeners as much as possible to make a better quality product.
Less congeners = less hangover
Re: Is it in the 5% or the 95%
Right plonker congeners isn't the right term. I just used the term congener to identify anything not water or ethanol.
As for boiling points, Photonic sent some wash, heads and finished product in for testing. Don't know what type of still. What surprised me was the fact that acetone having a boiling point 56.5ºC made it into the distilled and filtered product in the same proportion as in the wash and heads.
http://homedistiller.org/forum/viewtopi ... =1&t=12350
Also regarding flavor, I see you are well aware of the killer some great tasting compounds can be per kiwistiller here:
http://homedistiller.org/forum/viewtopi ... =1&t=10646
In the end it was a point about measuring and about a concept that is read often here that I believe is not accurate but as I said in the OP it has no practical end, just understanding.
As for boiling points, Photonic sent some wash, heads and finished product in for testing. Don't know what type of still. What surprised me was the fact that acetone having a boiling point 56.5ºC made it into the distilled and filtered product in the same proportion as in the wash and heads.
http://homedistiller.org/forum/viewtopi ... =1&t=12350
Also regarding flavor, I see you are well aware of the killer some great tasting compounds can be per kiwistiller here:
http://homedistiller.org/forum/viewtopi ... =1&t=10646
In the end it was a point about measuring and about a concept that is read often here that I believe is not accurate but as I said in the OP it has no practical end, just understanding.