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-   -   ABV of distilled with hydrometer (http://www.homebrewtalk.com/f128/abv-distilled-hydrometer-404118/)

Halbrust 04-10-2013 06:38 PM

ABV of distilled with hydrometer
I am not talking about distilling!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!

I am wondering if there is a way to determine alcohol content of a distilled alcohol after it has been "burned off" using a hydrometer.

Using a hydrometer.

The gravity of a spirit pre heating and post heating should be different. Is there a way to calculate remaining ABV from the difference in those numbers?

ajdelange 04-10-2013 07:04 PM

I'm not sure I understand the question but I think it is something like "If I light some Sambucca, extinguish the flame after a couple of seconds and then measure the specific gravity of what's left can I estimate the remaining alcohol?". Practically speaking the answer is no in this case because all the sugar obscures the effects on the alcohol. If the question were the same except that the beverage were Vodka then the answer would be yes. As vodka can be considered a binary mixture of water and ethanol a density measurement would be considered adequate for 'proofing' before or after partial combustion of the alcohol.

Where the obscuration is high (Sambucca) TTB would make you separate the alcohol from the liquor before the density measurement.

DisturbdChemist 04-10-2013 07:05 PM

I believe that they have a special hydrometer that measures "Proof". The brewing hydrometer might not read a 40 proof liquor. The SG might be below 1.000 but dont quote me on it.

Halbrust 04-10-2013 08:22 PM

The spirit in question is whiskey.
And rather than flambe it, I plan on heating it in a pan and holding it at a low simmer for around 10 minutes.

I'm trying to make a non alcoholic version of a mixed drink that uses blended Scottish whiskey.
For my purposes, I have to know how much alcohol is actually remaining in the spirit.

ajdelange 04-10-2013 09:28 PM

Depending on how much accuracy you need that is doable. Obtain a Tralle hydrometer. This is one designed especially for proofing. The reason for the accuracy comment is that the density of aqueous solutions of alcohol are not much different from that of water until the proof becomes appreciable meaning that the marks for the lower percentages are very close together and hard to read.

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