## Alcoholmeter

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Danespirit
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### Alcoholmeter

Besides the hydrometer (http://homedistiller.org/forum/viewtopi ... 7#p7337357) a alcoholmeter is the most important tool for the distiller.
It simply takes a lot of guesswork out of the equation.

There are several type of alcoholmeters the most common types of alcoholmeter are according to:
Weight %, volume % or previously acc. to Tralle %, proof %, Gay-Lussac % and Cartier.

The two most common types is what this thread refers to.

However, before we get into details, i would like to eliminate a common misunderstanding that seems to bother the new distiller.
The alcoholmeter measures the alcohol percentage in alcohol / water liquid only ! If you have sugar in your liquid you will get an uncorrect reading.

For this same reason a batch with a lot of unfermentable sugars in it like molasses in rum, will give a uncorrect reading on the alcoholmeter.
The best way to determine the alcoholcontaint in this case, would be by calculation based on the s.g.(speciffic gravity).

A alcoholmeter using the metric system, has typical a scale from 0 to 100%.
This however is only a hypotetical value, as the homedistiller won't distill higher than azeotrope conditions, which would be around 96 % Vol. (depending on hight over sealevel).
Distilling higher than this, would require vacuum distillation and is somewhat pointless as ethanol is hydrophilic and would be dilluted by the moisture in the surrounding air.

A alcoholmeter using the proofscale , works within the same parameters. The only difference would be the scale typical from 0 to 200 Proof.
Fortunatly conversion to metric is very simple, just divide the reading by two and you have % Vol. Vice versa..

Whatever type of alcoholmeter you have, it will only give a correct reading if the temperature of your distillate matches the temperature your alcoholmeter is calibrated to..! This would be between 15-20 C (it should be stated on your meter).

How to use:
For using an alcoholmeter you require a test jar to make an exact and easy reading! Before and after use clean the alcoholmeter and test jar with warm water and dry before use. The alcoholmeter should also be wiped dry with a linen cloth. After cleaning, the alcoholmeter should be held only from the thin part above the paper scale.
After sinking the meter into the liquid, you want to give it a slight spin. The reason for this, is to let gasbubbles that sticks to the meter escape, so they won't throw off your reading.
The following picture shows different types of alcoholmeter, with or without inbuild thermometer:
The picture below, shows where to read the meter.
Similar as the hydrometer, the alcoholmeter is read perpendicular to the testcylinder just were the surface is.
The liquid that creeps up the meter due to the cappilaryeffect, is ignored.
Alcoholmeter (1).jpg (2.49 KiB) Viewed 12394 times

still_stirrin
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### Re: Alcoholmeter

Another great one, Danespirit. Thanks.

I'm going to add this to my signature as well. Worthy reading for new brewers & distillers alike.
ss
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Danespirit
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### Re: Alcoholmeter

Thanks Still stirrin..

S-Cackalacky
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### Re: Alcoholmeter

Great write up. Hope this one gets stickied somewhere.
S-Cack,
Forum Contrarian

Every new member should read this before doing anything else:

columbia36
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### Re: Alcoholmeter

I've never tried it but I'm planning to on my next batch. A lot of the recipes do call for soaking the oak in spirits, but probably just to sanitize the wood. Something you don't worry about with 130 proof liquor. I suppose if you toasted and charred the oak, then immediately put it in the beer it would be sanitary enough.
I've got a jar of JD chips that I had some UJSSM on, and those are going into my next stout. Not adding any liquid spirit, just what's soaked into the wood.

columbia36
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### Re: Alcoholmeter

Oops, don't know how that post got here, meant to put it in the oaking beer thread!

BugHunter
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### Re: Alcoholmeter

One thing that probably should be mentioned is not to use a plastic test jar when measuring high %abv samples. It's pretty common to use plastic test jars for hydrometers for fermenting measurements, but higher concentrations of alcohol will attack many plastics. I've read of people watching their test jar disintegrate in the course of one still run. Use a glass test jar.

Antler24
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### Re: Alcoholmeter

BugHunter wrote:One thing that probably should be mentioned is not to use a plastic test jar when measuring high %abv samples. It's pretty common to use plastic test jars for hydrometers for fermenting measurements, but higher concentrations of alcohol will attack many plastics. I've read of people watching their test jar disintegrate in the course of one still run. Use a glass test jar.
I bought a graduated cylinder at my lhbs. It's same height as an alcometer, about 1.5inch diameter, and a wide base at the bottom so it can free stand, I love it. I think it was 9.99
Swedish Pride wrote:
get a brix reading on said ball bearings and then you can find out how much fermentables are in there

Danespirit
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### Re: Alcoholmeter

+ 1 on that glass cylinder. Never fall for the temptation to use synthetics stuff to hold high ABV spirits.
I use to buy a couple of them from Ebay they are really dirt cheap there and come in different sizes.
A 50 mL like the one in the link is perfect for the job. https://www.ebay.com/itm/Graduated-Glas ... Sw8w1YBtdf" onclick="window.open(this.href);return false;" rel="nofollow
Think it was 1.60 \$ for that one, so I bought three to have some spare ones.

Antler24
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### Re: Alcoholmeter

Danespirit wrote:+ 1 on that glass cylinder. Never fall for the temptation to use synthetics stuff to hold high ABV spirits.
I use to buy a couple of them from Ebay they are really dirt cheap there and come in different sizes.
A 50 mL like the one in the link is perfect for the job. https://www.ebay.com/itm/Graduated-Glas ... Sw8w1YBtdf" onclick="window.open(this.href);return false;" rel="nofollow
Think it was 1.60 \$ for that one, so I bought three to have some spare ones.
Mine is 250ml, I should pick up a 100ml keep the 250 for a spare.
Swedish Pride wrote:
get a brix reading on said ball bearings and then you can find out how much fermentables are in there

JK79sGin
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### Re: Alcoholmeter

I've just got my kit and am playing with things while I'm (impatiently) waiting for the wash to finish. Tested the alcoholmeter on the sloe gin I made last year. It reckoned it wasn't alcoholic at all so I did another reading on a commercially made gin, realising that the sugar content would knock off the readings. The bottle says 37.5%, meter says 14%. Can meters be that inaccurate or is it more likely user incompetence? The glass test jar was clean and dry, I spun the alcoholmeter, took reading from lower edge of the meniscus. How hard can it be?!

Danespirit
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### Re: Alcoholmeter

While (very) cheap alcoholmeters can be off a little it's highly unlikely it should be off by so much.
Take a clean glass and fill it with water then put the alcoholmeter in like you did. The reading should be exactly 0% at room temperature.
Most meters are calibrated to 20 C which would be 68 F. It likely the calibration temperature will be stated on the printed part of your meter.
Any kind of product that contains unfermented rest sugars will throw off the reading. Gin wouldn't be a product I would expect to do that.
Most commercial distilled gin would have a neutral spirit as a base spirit and that won't contain any sugars per se.

JK79sGin
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### Re: Alcoholmeter

Thanks Danespirit,
I've now rechecked various spirits as well as water. Most seem to be ok so the problem with the sloe gin must have been the quantity of sugar added! Interestingly, the commercial gin I tested yesterday as a comparison (Gordon's Pink gin) is still registering as 20% but the bottle says 37.5% There's maybe something else altering the reading or I've got a dodgy bottle!

SaltyStaves
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### Re: Alcoholmeter

Gordons Pink Gin is artificial trash. You're measuring all the additional sugar, flavouring and colourant.

JK79sGin
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### Re: Alcoholmeter

Yup, it just happened to be in the house. I'm waiting on my first wash finishing so I can learn to make a better alternative!

JK79sGin
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### Re: Alcoholmeter

This wee experiment has highlighted just how much "artificial trash" is actually in it! Quite interesting...

SaltyStaves
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### Re: Alcoholmeter

JK79sGin
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### Re: Alcoholmeter

That tallies with my readings
It's pretty interesting as I hadn't expected a professional product to vary so much. Hadn't realised how far from a 'proper gin' it is!

Corsaire
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### Re: Alcoholmeter

This test is very popular with the rum crowd. It's a dead giveaway when a 'premium' rum has been altered with added sugar or worse.

Danespirit
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### Re: Alcoholmeter

+1 Corsaire
Added sugar will always alter the reading.
More than likely it's what has been done to the gin in the picture.
It would be interesting to know if color additives have a similar effect even if they are not based on glucose...?

RickRay
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### Re: Alcoholmeter

I have a number of 60 farenheit degree calibrated alcoholmeters, does anyone know of a free calculator or table for temperature correction. I'm able to find lots of 20 degree celcius calculators and tables, but no 60 degree farenheit calculators or tables.

NJen
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### Re: Alcoholmeter

There used to be a calculator on the main page that was nice, but it doesn't look like that works anymore. The TBB has a chart indicating ºF spirit hydrometer gauging, posted here. Not sure if this will really be of any help or not, but it's what information I could find.

60ºF is contained on pages 41-44.

RickRay
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### Re: Alcoholmeter

Exactly what I was looking for, I used to use the calculator on the front page until it stopped working. I never knew how hard it was to find info on the 60 degree calibration hydrometers.

THANKS!

cayars
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### Re: Alcoholmeter

If you track things in a spreadsheet or use that to formulate recipes you can use it to do the math for you. Here is the info you need:

cg = corrected gravity
mg = measured gravity
tr = temperature at time of reading
tc = calibration temperature of hydrometer

cg = mg * ((1.00130346 - 0.000134722124 * tr + 0.00000204052596 * tr2 - 0.00000000232820948 * tr3) / (1.00130346 - 0.000134722124 * tc + 0.00000204052596 * tc2 - 0.00000000232820948 * tc3))

tr2 means tr squared, tc3 means tc cubed, etc

Or lets just use this.
formula.png (3.18 KiB) Viewed 3804 times
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