Measuring alcohol percentage by freezing point?

[SimPilot]

Has anyone tried this method?

Stick a thermometer into a glass in your freezer and record freezing point. Then using calculator you get ABV....

https://shotgundentist.com/blog/usefull-tools/alcohol-percentage-to-freezing-point-calculator/
Am I missing anything?

 

[jpitz31]

I am assuming you are putting fermented beer into the glass, in order to measure amount of alcohol in the beer, based on temp. More alcohol lower freezing point. But how will you know at what point it freezes, you will have to keep opening the door and keep checking the temp, based on the online calculator. Sounds like a cool experiment, but lots of work and time involved.

 

[GuldTuborg]

That only seems to make sense if you assume your liquid has only water and alcohol in it. In some cases you may be able to assume this. In others, it would be a faulty assumption. For example, if you try to use this on a very sweet sack mead, the sugar itself would cause a change in the freezing point, throwing off your calculations.

 

[SimPilot]

After a quick test, I think this is a piss poor idea. I tried on one of the batches, but crystallization started around -6C and if continued, glass would break. Constantly checking freezer to see if it's "frozen", is a pain in you know what.
In addition as GuldTuborg said, additional sugar changes freezing point.

 

[AZCoolerBrewer]

Interesting idea. Made me think. Thanks for sharing. Some thoughts I had concerning this are that this is how people jack beer/cider to concentrate the alcohol. As the alcohol comes out of solution you have two different ABV levels, that of the frozen part and that of the part that remains liquid. It would make things very hard to measure.

 

[bracconiere]

wouldn't it need stiring also, other wise it's going to freeze distill?