Freezing point of Absolut Vodka?

murphaph

Ok, here's the gen. I always keep my trusty bottle of Absolut in the freezer. It's never frozen before given it contains 40% alc. vol. I think somebody's been topping it up with water because it was a solid block of ice with a tiny amount of liquid at the bottom of the bottle this morning. Either that, or my freezer's thermostat is on the blink!

So, anybody know (or know how to work out) the freezing point of unadulterated Absolut???

dudara

Have a look here . They calculate that 40% alcohol should freeze somewhere around -20 deg Celcius. A domestic freezer is somewhere in the region of -18 deg. So therefore it is possible that the alcohol is freezing of it's own accord.

But this is of course open to contradiction, as I didn't do the calculation myself.

If the above calculation isn't true, the secret drinker would have to have added a fair bit of water in order to cause the vodka to freeze. Surely you'd taste the difference!

span

Untampered vodka (40%) has a freezing point of minus 30. It looks like someone's been topping up your vodka

c - 13

Most sources (from google) say about - 29 degrees c, so yep, looks like someones been helping themselves.

vibe666

i've had a bottle of the citrus absolut in my freezer that i've been having the odd sup of. it's about half full and hasn't gone more than slightly syrupy in the whole time it's been there.

think you might have a secret absolut drinker in your house!

murphaph

I knew it! I'll kill the little sh!t. I haven't been able to taste it yet as it's still defrosting in my fridge. I've been keeping vodka in the freezer for years and all it's ever done is go lovely and syrupy, never before has so much as a single ice crystal formed!

Thanks guys. Now to get worked in a drunken rage, oh wait, arrghhh....

nesf

Damn fine thread!!!

Practical and scientific!

I loves it.


And yes, everyone is in agreement, someone has been "tampering" with your vodka. This isn't the first time I've seen this happen though

Capt'n Midnight

You could try to measure the density with a hygrometer or perhaps the refractive index by measuring the angle light bends. The nice thing about the second method is that it could be done in an off-license and no alcohol is wasted.

As for the hygrometer a small piece of cork with a toothpick in it and something to weigh it down, like thumbtacks ?

nesf

Capt'n Midnight wrote:

You could try to measure the density with a hygrometer or perhaps the refractive index by measuring the angle light bends. The nice thing about the second method is that it could be done in an off-license and no alcohol is wasted.

As for the hygrometer a small piece of cork with a toothpick in it and something to weigh it down, like thumbtacks ?

Eh.

He'd need a hollow prism or square glass to test the refractive index (not exactly common household items tbh). A round bottle means no angle with which to measue from remember (or at least, not a big enough angle to make a practical difference).

The second method you proposed would be a) inaccurate, b) a waste of good alcohol (as you noted yourself) and c) a bit pointless since the density difference would not necessarily be much if there wasn't much water added. However a small bit of water could cause the alcohol to freeze.

And both would require a lot of effort, testing and calibrating to be of use. I'm questioning more the practicality of the methods for a "regular person" here rather than attacking them. What you said was valid in a sense but I don't think it's of much use to anyone who doesn't have 4/5 hours to kill by setting up and testing the equipment. He knows it's not 40% proof, it froze. There is only 1 way this could happen, realistically. Plus it sounds like he knows who the culprit is, so I think it's a foregone conclusion really...


Personally, and this is just me, I'd just buy a second bottle and try and taste the difference.


Of course, the scientific method would require that such testing be repeated at lenght to ensure accuracy.


(Btw, I'm very tired atm so if I'm coming across badly or harshly just chalk it upto the need for sleep or something)

murphaph

I could of course buy another bottle of sealed Absolut-pop it in the freezer with the suspect bottle and if one freezes and the other doesn't.....we have the answer, unless vodka is like brake fluid and absorbs moisture from the air!

(what's the word for that, hydroscopic or something?-I'm no chemist!)

Delphi91

Left a bottle of wine in the freezer recently. Needed to cool it down quickly but forgot about it and it froze!

I expected a mass of shattered glass all over the freezer, however the bottle was intact! The wine froze, slowly pushed the cork out through the foil top and all we had was a small frozen drop hanging from the top of the bottle (the bottle was on its side)

Mike

D-Generate

The Leaving Cert physics course has an experiment on the refractive index of water using

Beaker filled with water up to the brim with a pin at the bottom.
Place a mirror on top of this so that the water is just touching the back of the mirror
Have a pin stuck in to a cork clamped on a retort stand above the mirror.
Adjust the distance between the pin in cork and the mirror until the pin in the cork looks the same size as the pin in the water and no parallex has occured.
Then measure depth of water (real depth) and length between mirror and pin in cork (apparent depth)

Refractive Index = Real Depth/ Apparent Depth

Or something like that.
I know its probably so inaccurate but if you do the same test on two bottles of Absolut then won't the inaccuracy cancel each other out?
Huzzah.

dudara

D-Generate wrote:

The Leaving Cert physics course has an experiment on the refractive index of water using

Beaker filled with water up to the brim with a pin at the bottom.
Place a mirror on top of this so that the water is just touching the back of the mirror
Have a pin stuck in to a cork clamped on a retort stand above the mirror.
Adjust the distance between the pin in cork and the mirror until the pin in the cork looks the same size as the pin in the water and no parallex has occured.
Then measure depth of water (real depth) and length between mirror and pin in cork (apparent depth)

Refractive Index = Real Depth/ Apparent Depth

Or something like that.
I know its probably so inaccurate but if you do the same test on two bottles of Absolut then won't the inaccuracy cancel each other out?
Huzzah.

Old skool!! I like

The only problem with such measurements arises from the relative closeness of the refractive indices of water (n=1.333) and alcohol (n=1.329). Unless you've a very tight experimental setup, the error is going to be too large to permit you to determine the truth about your suspected alcohol thief!

ApeXaviour

dudara wrote:

Old skool!! I like

The only problem with such measurements arises from the relative closeness of the refractive indices of water (n=1.333) and alcohol (n=1.329).

Agreed.. The most effective way of measuring alcohol is using a hydrometer. I do this surprisingly often. Unless you have a chem supplier / lab nearby a <1 SG (specific gravity) hydrometer can be hard to come by. Specific gravity is just density, or grams per millilitre.

You can try and measure what percentage it is if you want? Just put your (suspect watered down) absolut in a measuring jug, and weigh it. Then divide its weight in grams by how many mls it is. And figure the percentage from this attached table:

Delphi91

ApeXaviour wrote:

...Specific gravity is just density, or grams per millilitre...

Actually it isn't! What you've defined is density. Specific Gravity is also called "relative density" and it's just a number with no units. It's defined as the density of a substance relative to water and is found by dividing the mass of any volume of a substance by the mass of an equal volume of water.

ApeXaviour

There's an over-pedantic attention to detail if I ever saw it. Damn physicists..
I didn't say it was defined as density. :rolleyes: but in this specific case (bar the units) they are the same thing. I didn't feel there was a need to complicate matters by getting into semantics.

Delphi91

ApeXaviour wrote:

There's an over-pedantic attention to detail if I ever saw it. Damn physicists..

Ah but you love us all the same!!

I didn't say it was defined as density. :rolleyes: but in this specific case (bar the units) they are the same thing...

In ALL cases it's numerically the same because of the very convenient density of water (1 g/cm^3 or 1000 kg/m^3)

stevenmu

It could actually be something to do with the quantity of vodka left in the bottle and the air pressure inside it. Because water expands when it freezes a higher air pressure or less space in side the bottle means it would require a colder temperature to freeze, conversely more free space inside the bottle or a lower air pressure means it could freeze at a much warmer temperature.

I use the freezer to cool beer bottles and if I leave them in too long they come out as a perfect liquid but when I remove the cap, releasing the air pressure, it turns to ice. It actually looks really cool as the ice 'spreads' through the bottle, apart from the waste of alcohol that is

ApeXaviour

stevenmu wrote:

It could actually be something to do with the quantity of vodka left in the bottle and the air pressure inside it. Because water expands when it freezes a higher air pressure or less space in side the bottle means it would require a colder temperature to freeze, conversely more free space inside the bottle or a lower air pressure means it could freeze at a much warmer temperature.

Heheh good thinking there! Thing is though that the cooled air would compress/lose pressure at a much larger rate than the water expands. So the effect would actually be negligible I think.

stevenmu wrote:

I use the freezer to cool beer bottles and if I leave them in too long they come out as a perfect liquid but when I remove the cap, releasing the air pressure, it turns to ice. It actually looks really cool as the ice 'spreads' through the bottle, apart from the waste of alcohol that is

Yeah I've seen this with bottles of pepsi in the freezer too, it's pretty fkin neat I'll agree. I've a feeling though that this is more to do with the "added air pressure" caused by the release of CO2. I havent thought this through fully but I'd hypothosise that the CO2 "expanding" out of the bottle when you open it acts like a heat pump in a fridge and removes heat from the bottle, also there's the added fact that the liquid is under pressure.
Anyone able to clarify my convoluted response?

stevenmu

ApeXaviour wrote:

Thing is though that the cooled air would compress/lose pressure at a much larger rate than the water expands. So the effect would actually be negligible I think.

Wouldn't that mean that an emptier bottle would contain more air, thus leading to a greater drop in pressure meanind the vodka could freeze easier ?

ApeXaviour wrote:

Yeah I've seen this with bottles of pepsi in the freezer too, it's pretty fkin neat I'll agree. I've a feeling though that this is more to do with the "added air pressure" caused by the release of CO2. I havent thought this through fully but I'd hypothosise that the CO2 "expanding" out of the bottle when you open it acts like a heat pump in a fridge and removes heat from the bottle, also there's the added fact that the liquid is under pressure.
Anyone able to clarify my convoluted response?

I suppose as the beer/pepsi cools it's going to be able to hold less dissolved CO2, as this gets released it'll increase the pressure, letting the liquid go colder without freezing. Not sure about the heat pump idea but it does make sense, I've no idea how much of an effect it would make though.


All these important unaswered questions. I think we'll need to replicate a pub under laborotory conditions (i.e. get a research grant to pay for the drink) to try and duplicate these phenomona

Scruff

Your post was funny but I'm afraid some muppet will take it seriously and try doing what you said.

So had to remove it.

Sorrys.

-nesf

Scruff

ye cant say anything these days can you?
*sigh*

nesf

Scruff wrote:

ye cant say anything these days can you?
*sigh*

I know, annoying, but someone has to protect the idiots from themselves.

james2323

I'm afraid, you may be missing an important possibility, and that your vodka thief may not exist.

Each time you open your bottle of vodka, you allow in air from your kitchen into the bottle. When you then place the bottle back in the freezer, the water vapor in that air condenses in liquid water, effectively watering down your vodka. The more you drink, the more space in the bottle, and the greater opportunity for water to condense again.

So, you may find that as you get to the bottom of your bottle, you have indadvertedly watered down your vodka to the point that the solution is week enough to freeze in your freezer.

Thus, I would not be so quick to blame your housemate.

Good luck!

vibe666

james2323 wrote: »

I'm afraid, you may be missing an important possibility, and that your vodka thief may not exist.

Each time you open your bottle of vodka, you allow in air from your kitchen into the bottle. When you then place the bottle back in the freezer, the water vapor in that air condenses in liquid water, effectively watering down your vodka. The more you drink, the more space in the bottle, and the greater opportunity for water to condense again.

So, you may find that as you get to the bottom of your bottle, you have indadvertedly watered down your vodka to the point that the solution is week enough to freeze in your freezer.

Thus, I would not be so quick to blame your housemate.

Good luck!

you may want to consider travelling back in time to 2005 when the last post was on this thread and then posting it then instead of now in 2011. just a thought. good first post though, except it's not true. well, not in enough of a concentration to cause your vodka to freeze, no matter how much of it you drink.

gman2k

Funny this thread popping up again, as I've a frozen bottle of Absolut in the freezer.
Simply solution to the "why is it frozen?" is that somebody messed with my fridge controls and really dropped the temp! Ice cream took an age to thaw out before it could even be scooped!

vibe666

gman2k wrote: »

Funny this thread popping up again, as I've a frozen bottle of Absolut in the freezer.
Simply solution to the "why is it frozen?" is that somebody messed with my fridge controls and really dropped the temp! Ice cream took an age to thaw out before it could even be scooped!

i keep my new freezer (with digital temp controls) at -25 degrees celcius (colder than most domestic freezers will even go) and i have had a bottle of absolut (no, not the same one as in 2005) in there for over a year and so far it hasn't frozen, so unless you have some kind of industrial strength freezer, someone has been diluting your vodka.

ApeXaviour

vibe666 wrote: »

i keep my new freezer (with digital temp controls) at -25 degrees celcius and i have had a bottle of absolut in there for over a year and so far it hasn't frozen, so unless you have some kind of industrial strength freezer, someone has been diluting your vodka.

So because my phd thesis is due next month I managed some great procrastination... the intention being to back you up since I myself haven't seen vodka get anything but a bit viscous.... but it seems the figures disagree.

So I used a combination of datapoints from Lange's Handbook of Chemistry (via Wikipedia), and a website called Engineering Toolbox. Plotted them, fitted a (9th order) polynomial curve to it. Here's said fit with two lines for Smirnoff (37.5% Vol) and Absolut (40% Vol).





So it came out at approximately -20.7 C for Smirnoff and -23.1 C for Absolut.

My guess is either the thermostat on your freezer isn't calibrated or your freezer heat-pump/insulation isn't up to a 50 degree differential. Could be the alcohol percentage is wrong too. If it was even 43% it wouldn't freeze until -26.

vibe666

ApeXaviour wrote: »

My guess is either the thermostat on your freezer isn't calibrated or your freezer heat-pump/insulation isn't up to a 50 degree differential. Could be the alcohol percentage is wrong too. If it was even 43% it wouldn't freeze until -26.

now i just want to see how cold it WILL go.

just bought a -50 degrees thermometer online to test it properly, so i guess we'll see for definite soon enough.

vibe666

amazingly enough, my thermometer arrived today and i was testing it in the freezer, but it seems like -25 on the digital controls on the freezer only equals -15 in real world temps, so my vodka has never even hit -20.