Using a Hydrometer with Liqueurs and thickened liquors

[OCDistiller]

I bought a hydrometer to find the proofs of a honey liqueur, a spiced rum, and a bourbon I've made. I started with the honey liqueur and realized that the sugar content is changing the specific gravity of the liquid to the point that I couldn't find the proof.

Also, I've added small amounts of glycerine to both the spiced rum and the bourbon (5ml/Liter). Won't this also throw off the hydrometer?

How do I use the hydrometer to find the proof of these thicker-than-usual products I've made?

Thanks!

[rubber duck]

You can't.

There is an equation or way to do it, I'll see if I can find it.

[rubber duck]

Here you go.

http://www.ttb.gov/foia/gauging_manual_ ... 25.4.504.2" onclick="window.open(this.href);return false;" rel="nofollow

Basically your going to need a small lab still. The term is obscuration, or proof obscuration.

[Prairiepiss]

Or just figure it out by volumes used.

If you add 100ml of sugar to 100ml of 50% ABV you would get 200 ml of 25%. This would get you close enough for what we do.

[OCDistiller]

Yeah, I've already estimated it by volume but figured it'd be nice to be spot-on.

So even that small amount of glycerin would make it unreadable?

Thanks for your input guys

[Dnderhead]

its not so much the thickness ,its the diferance in pacific gravaty or weight of displacement.
so unless you add something with the same weight as water a hydrometer will not be correct.

[OCDistiller]

Ok, but just to be clear, you're all saying that adding 5ml/liter of glycerin will make the alcohol proof unreadable by a hydrometer?

[Prairiepiss]

Yes he is. Anything but water and alcohol will skew the readings.