DIY alcohol meter

[October]

Hi, my second post here. I was wondering why there are no DIY Alcoholmeters. For Hydrometers I have found a good method like this video:


But I thought about making an Alcoholmeter based on 99.9% Isopropyl Alcohol. Tell me if I am wrong. You drop first the straw using the Isopropyl Alcohol, this will mark the 99.9% ABV on the floating straw. Then you dilute 1 part Isopropyl Alcohol together with 9 parts water, the straw will float at mark 10% ABV. Then you mix 2 parts Isopropyl Alcohol and 8 parts water, this will mark the 20% on the straw, and so on. What do you think?

[still_stirrin]

Question is … why?

You can buy a Proof & Traille hydrometer online for less than $10USD. Trying to “make” one is hardly less expensive, especially when you consider accuracy.

Oh, and when you do order one, order 2. They’re fragile and all it takes is one oooops!
ss

[October]

Question is … why?

You can buy a Proof & Traille hydrometer online for less than $10USD. Trying to “make” one is hardly less expensive, especially when you consider accuracy.

Oh, and when you do order one, order 2. They’re fragile and all it takes is one oooops!
ss

Yes I know they are cheap. But just for the fun of making one.

[ShineonCrazyDiamond]

Sounds like a perfect thing for you to share with us. Why don't you do it and contribute your experience. Seems better than just asking everyone else why it hasn't been done.

[elbono]

Question is … why?

I do all kinds of stuff that applies to. The answer is always "Because!"

[Setsumi]

Didn't Rad had a straw hydrometer for fermentation? But I am with SS on this one.

Mind mine is 0 to 100% and I have a short 70 - 100%. Neither is vey acurate but better than 3%... okay <5%.

[October]

Sounds like a perfect thing for you to share with us. Why don't you do it and contribute your experience. Seems better than just asking everyone else why it hasn't been done.

Of course I will. I was just asking for any possible advise. My guess is that the longer the straw the better and more accurate. So for example, in that youtube video the straw is just too short, something like 15cm instead of 40 cm.

[kennstminet]

I'm afraid the density of Isopropyl Alcohol is different from Ethanol.
You need to find a correction. I addition the density changes with temperature. The temperature coefficient for Isopropyl Alcohol is different from Ethanol. You would need to create a suitable temperature correction chart.

[October]

I'm afraid the density of Isopropyl Alcohol is different from Ethanol.
You need to find a correction. I addition the density changes with temperature. The temperature coefficient for Isopropyl Alcohol is different from Ethanol. You would need to create a suitable temperature correction chart.

Is that really different from ethanol, considering that as soon as you have it out is going to absorb some moister from the air? Regarding the temperature, can I use my own standard? For example I will always use a sample coming from the fridge, this way the temperature will be always the same.

[October]

From google, density of isopropyl alcohol is 786 kg/m³, and density of 100% ethanol 789 kg/m³.

[kennstminet]

A Water Ethanol mixture of 40% ABV has a density of 948
With 42%, the density will be 945.
The difference of 3 kg/m^3 makes an error of 2% ABV.
Go ahead with your plan, if you think that this difference is not appreciable.

[juana_b]

Beaver has done this also

But I wouldn't put that in my likker.
app.php/rules#Safety_First

[October]

A Water Ethanol mixture of 40% ABV has a density of 948
With 42%, the density will be 945.
The difference of 3 kg/m^3 makes an error of 2% ABV.
Go ahead with your plan, if you think that this difference is not appreciable.

Yes, I don't mind 2% difference.

[October]

Beaver has done this also

But I wouldn't put that in my likker.
app.php/rules#Safety_First

Nice, but he's adapting his straws to premade scales, and he ends up with a short tool. I will do the opposite, I will adapt the scale to the Isopropil alcohol, and go from there. I am going to join three transparent bic pens and seal with gorilla glue.

[elbono]

I am going to join three transparent bic pens and seal with gorilla glue.

I'm the sorta guy that would do this to prove I can but if you get it to work throw the sample in the charcoal starter/glass cleaner can. No way I would drink something I put bic pens or gorilla glue in, you shouldn't either.

[October]

I am going to join three transparent bic pens and seal with gorilla glue.

I'm the sorta guy that would do this to prove I can but if you get it to work throw the sample in the charcoal starter/glass cleaner can. No way I would drink something I put bic pens or gorilla glue in, you shouldn't either.

Of course I will bleach everything thoroughly!

[ShineonCrazyDiamond]

Missing the point about poisoning yourself.

[jonnys_spirit]

This could be useful for a wort in a pinch and you really only need to calibrate it @ 1.000 (water) to measure how complete fermentation is but not with plastic and high proof ethanol.

Or just buy a few

Cheers,
jonny

[Bee]

Glass pipettes are easy to get and easy to work.