Measuring alcohol content of diluted liquor

[Grayson_Stewart]

Brought over from old forum

sontay
(stranger)
09/17/04 08:49 PM

Measuring alcohol content of diluted liquor

I have an ebulliometer that can measure concentrations up to 20%. If I want to measure higher concentrations I have to dilute the liquor down and measure the diluted one. How do I calculate the concentration of the original liquor if I have only the volume (or weight) of the original liquor and the added water?
I guess it is calculated with mass concentration (%mas).

Any suggestions?

Cheers
Son Tay

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theholymackerel
(addict)
09/17/04 09:43 PM

Re: Measuring alcohol content of diluted liquor new [re: sontay]

Why not just buy a proof hydrometer? Or make one?

They are very inexpensive and can be mail ordered from most any brewin' supply store.


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nzbourbonhead
(newbie)
09/17/04 09:58 PM

Re: Measuring alcohol content of diluted liquor new [re: theholymackerel]

If you add same amout of water as you have distillate will drop the abv by a half so 50% becomes 25% if you do it again say your distillate still over 20 will drop by half again ie 12.5%

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sontay
(stranger)
09/18/04 02:53 AM

Re: Measuring alcohol content of diluted liquor new [re: nzbourbonhead]

But mixing 1 liter of water and 1 liter of 100% alcohol doesn't result in 2 liters of 50% alcohol! It's the contarction that makes my life difficult.
So, if I've got 100ml of alcohol with unknown concentration and add 100ml of water I won't get 200ml. But, once I know the concentration of the mix how do I calculate the concentration of the original liquor?

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rebel
(journeyman)
09/18/04 03:27 AM

Re: Measuring alcohol content of diluted liquor new [re: sontay]

sontay, People here do not like to answer a question that is already on the website. The information you seek is on the site under "distilling" and this post probably belongs somewhere else in the forum. I'm not being a dick, I'm just telling you how it is here. and the answer is to buy and learn how to use an alcohometer. that one is free but make sure you look on the site cause the chances are that you question was answered there.

make beer not war

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nzbourbonhead
(newbie)
09/18/04 03:58 AM

Re: Measuring alcohol content of diluted liquor new [re: rebel]

ok picture this 10 litres if 50% alc is 5 litres of alc at 100% abv
add another 10 litres 0% alc you have 20 litres at 25% alc as as in 10 litres at 50% alc = 5 litres at 100 alc other 5 litres is water if you add another 10 litres of water alc contebt is still 5 litres so its now 25% alc of 20 litres
hope this makes sense as been on 37.5alc home brewed bourbon lol
So just add water till you get to readable on your herdy gerdy and do the maths lol

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nzbourbonhead
(newbie)
09/18/04 03:59 AM

Re: Measuring alcohol content of diluted liquor new [re: nzbourbonhead]

Shit when did I become a newbie lol

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theholymackerel
(addict)
09/18/04 06:23 AM

Re: Measuring alcohol content of diluted liquor new [re: sontay]

>>But mixing 1 liter of water and 1 liter of 100% alcohol doesn't result in 2 liters of 50% alcohol!<<

True. And the problem is again complicated by the fact that ebulliometers (for testin' wine strength) are HORRIBLY inaccurate.

So if yer bullheaded enough to insist on usin' an ebulliometer to mesure yer distillate, all i can say is good luck, 'cause whatever ABV ya come up with just be a guess.

On the other hand if ya spend 9$ (cheap) on a proof hydrometer (the proper tool for the job) you can have an exact ABV if yer careful with temperatures.


I really don't see the problem here: use the proper tool for the proper job.


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nzbourbonhead
(newbie)
09/18/04 06:59 AM

Re: Measuring alcohol content of diluted liquor new [re: theholymackerel]

ok if not what does it result in half of 100% = 50 % to me if you had say 100 litres of molasses added 100 litres of water you have 50% molassses and 50% water the same as alcohol

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theholymackerel
(addict)
09/18/04 07:29 AM

Re: Measuring alcohol content of diluted liquor new [re: nzbourbonhead]

I'll use yer example of 110 litres of molassas and 100 litres of water.

The combined weight WILL be simply the the weight of the water and molassas added together, but you will not get 200 litres of diluted molassas. It will be less than 200 litres.

Test this. Take 200 ml of sugar and 200ml of water and mix 'em. How many ml total do ya now have?

See? Water and alcohol work like this too, just a different principal.

nzbourbonhead
(newbie)
09/18/04 07:50 AM

Re: Measuring alcohol content of diluted liquor new [re: theholymackerel]

grr get out your hydrometer and test some spirit measure your abv pour intoi a glass add the same amount of water and do another test your abv will be half of what it was before adding water as you have watered down by fifty percent

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nzbourbonhead
(newbie)
09/18/04 07:54 AM

Re: Measuring alcohol content of diluted liquor new [re: theholymackerel]

not talking weights here but pure volume

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nzbourbonhead
(newbie)
09/18/04 08:12 AM

Re: Measuring alcohol content of diluted liquor new [re: theholymackerel]

>>But mixing 1 liter of water and 1 liter of 100% alcohol doesn't result in 2 liters of 50% alcohol!<< Hmm so what do you reckon you would get.. seems a simple maths problem to me. If you dont have 1 litre of 100% alcohol mixed with 1 litre of water what have you got? Has something gone missing or something been added?

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nzbourbonhead
(newbie)
09/18/04 08:37 AM

Re: Measuring alcohol content of diluted liquor new [re: sontay]

Are you using a pot still or a reflux If a pot still you should be able to work it like this.. add to 1 litre of spirit or in these proportions to 3 litres of water that will give you 25% reading of whatever your spirit is at start. pot still gives around 50 to 55% so a quarter of that is around 12 - 15% which is under 20 so your meter should be able to read it..
If reflux you will need to go one more stage to get under the 20% so 7 litres of water to 1 litre of spirit or as stated before the equivilent proportions and measure spirit then multiply by 8 instead of 4 so for pot still 1 part spirit to 3 parts water then multiply reading by 4 .... reflux 1 part spirit 7 parts water then multiply reading by 8

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theholymackerel
(addict)
09/18/04 09:04 AM

Re: Measuring alcohol content of diluted liquor new [re: nzbourbonhead]

>>grr get out your hydrometer and test some spirit measure your abv pour intoi a glass add the same amount of water and do another test your abv will be half of what it was before adding water as you have watered down by fifty percent<<

Grrr! No, you get out YOUR hydrometer, thermometer, and graduated cylinder and YOU test it. I tested it years ago. It's obvious yer not familiar with this little physics experiment, so do the experiment before gettin' all upset.


>>not talking weights here but pure volume<<

Me too.


>> >>But mixing 1 liter of water and 1 liter of 100% alcohol doesn't result in 2 liters of 50% alcohol!<< Hmm so what do you reckon you would get.. seems a simple maths problem to me. If you dont have 1 litre of 100% alcohol mixed with 1 litre of water what have you got? Has something gone missing or something been added? <<


Its not a simple math problem... it's a rather involved physics concept.

Nothin' has gone missin' , or been added... it's just simply a smaller volume after mixin'.

I cut and pasted this explanation from a fun site where folks get to ask questions of DOE scientists:
Question - When alcohol and water combine to take up less volume
(than all water), is it because the water molecules compact into the
alcohol molecules due to the alcohol molecule being more spacious? If
not, what causes the decrease in volume?
----------------------------------------
There are many examples of liquids that have a negative volume of mixing.
The reasons are not always evident, and are frequently restatements of "It
happens because it happens." rather than providing a fundamental explanation
that can be independently tested experimentally. In the case of ethanol and
water, the "reason" is that liquid water has a rather "open" structure due
to hydrogen bonding. The same is not so true of ethanol. So when the two are
mixed, the ethanol interferes with this "open" structure of water and causes
it to "collapse", and hence reduce the volume relative to the sum of the
volumes of the components. A related property of water is the minimum in the
molar volume at about 4C. If a water soluble solid has an "open" structure
that can be made more compact by dissolving, one would expect a similar
result. It is difficult to predict if and when it will happen because it
could also depend upon the temperature and the pressure at which the
components are mixed. That is why I choose to say the explanation is "It
happens because it happens."


I'm sorry that the idea that one litre of water and one liter of 100% alcohol mixed will neither be two liters in volume, nor 50% abv disturbs you so, but it's a demonstrateable fact.


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nzbourbonhead
(newbie)
09/18/04 09:25 AM

Re: Measuring alcohol content of diluted liquor new [re: theholymackerel]

Ok if this is the case and say the hydrometer test was at 20 deg celsius and you added the same volume of water I stiill think that you would still be within 1 or 2% in accuracy of the abv. Now I cant see any poblem with that .. Even a spirit hydrometer is hard to read within a couple of percent to me.

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theholymackerel
(addict)
09/18/04 09:39 AM

Re: Measuring alcohol content of diluted liquor new [re: nzbourbonhead]

It stands that one litre of water and one litre of 100% alcohol mixed make neither two litres, nor is the mix 50%.

Even if the differences in the volume and the abv are small, that small error compounds the LARGE error inherant in ebulliometers. You will end up with numbers that do not resemble anythin' close to reality.

This is why I origionally told him to get a proof hydrometer. If yer careful with temperatures then a hydrometer can be VERY accurate, and it's the ONLY accurate way to measure abv without spendin' a crap-load of money.

If ya don't care what the abv is then just mix to taste.

If ya do care what the abv is use a hydrometer. Usin' this honked up method of dilution and an ebulliometer is about as accurate as askin' a psychic.

Nuff said.

I'm done with this subject.


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tater
(addict)
09/18/04 09:43 AM

Re: Measuring alcohol content of diluted liquor new [re: theholymackerel]

lol


Theres more old drunks then there are old doctors

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rebel
(journeyman)
09/18/04 11:22 AM

Re: Measuring alcohol content of diluted liquor new [re: tater]

i just went to my local brewing store and picked up a proof hydrometerfor $8 us. it told me in about 2 minutes that my distillate was 90% alcohol easy, cheap and the proper tool for the job.

make beer not war

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Knuklehead
(enthusiast)
09/18/04 09:29 PM

Re: Measuring alcohol content of diluted liquor new [re: theholymackerel]

After I read this thread I went to cut some product. I always use the dilution calculator on homedistiller.org and it is always incorrect. I always have to add more water then the calculator says. Today I punched in 1 liter of 100% alcohol cut down to 50% and it calculated to add 1 liter of water. So the calculator is set up wrong this would explain why I always have to add more water then it said. Thanks for the explanation THM. Mixing water and alcohol also generates a bit of heat so I guess this would further prove there is some molecular activity going on.

theholymackerel
(addict)
09/18/04 09:43 PM

Re: Measuring alcohol content of diluted liquor new [re: Knuklehead]

That dilution calculator has never worked right for me either.

I tend to dilute whole batches at a time after they have aged. My method involves addin' small amouns of water at a time and frequent checkin' of ABV with a hydrometer.

When I make whiskey I tend to take 550 ml of my distillate (bulk aged at 110 proof) and add 200 ml of filtered water to make a "bottle". This ends up more than 80 proof, but it tastes "right" to me.


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ProfessorDuck
(journeyman)
09/18/04 11:54 PM

Re: Measuring alcohol content of diluted liquor new [re: theholymackerel]

I think the easiest way of diluting is to leave the alcometer in there and slowly pour in water until the reading is right. I haven't tried it though, because the top of my alcometer broke off so I would have filled the alcometer with water.