Accuracy of hydrometer

[Reefer1]

Hey you guys.
Can i ask, how accurate are proof&trail hydrometers at lower abv's namely 15 to 30abv,
So my next wash i will be doing a strip run as advised by you guys, aiming for 25abv, i dont have a refracter, can i use my P/T hydrometer, will it be accurate.
Thanks oh wise ones

[Deplorable]

It should be fine. I strip down to about 5% ABV off the spout or less and my collected low wines are usually between 28 to 32%.
You can always test it in a vial of distilled water and a vial of store-bought 100 proof vodka.
Be sure you are correcting for temperature.

[Saltbush Bill]

Don't you use an alcometer for measuring ABV

[bilgriss]

I believe an Alcometer is a Proof and Tralle hydrometer.

Words.

And related to the question related to a refractometer, I found this interesting thread from a few back: viewtopic.php?t=70357

[kennstminet]

Put your hydrometer in distilled water at the specified temperature and look for 0%abv indication.
If it is off by 0,5%abv, it is likely to have a similar offset at 15%abv.

[NZChris]

Put your hydrometer in distilled water at the specified temperature and look for 0%abv indication.
If it is off by 0,5%abv, it is likely to have a similar offset at 15%abv.

That's not quite correct. The scale isn't linear. If it is off by 1mm at 0%, it will be off by 1mm for the whole scale. I have one that is off by 3mm.

[Yummyrum]

Agree with Chris , it’s usually the paper that moves , but thr 0% calibration with water at temp will show that up .

The scale is more crammed at the lower alc end but I find my 0-100% meter is fine for most on the fly testing .
I have a 0-40% one and a 70-100% one for more accurate readings . Just got to get one that does the middle range .

[Reefer1]

Thanks all, i will test my p/t hydometer,
I only asked this because i read a while back they where not too accurate at lower abv, obviously not to be used to test a wash/mash after ferment for abv.
Thanks for your opinions guys.

[kennstminet]

An alcoholmeter can only be accurate in a pure water ethanol mixture.
A wash or mash contains other substances which affect the density and a density based device like hydrometer or alcoholmeter will not be able to measure the abv directly.

[NZChris]

It depends on the quality you bought. A certified hydrometer isn't cheap. I only have one and that was a lucky score.

For running a still, accuracy isn't super important unless you are commercial. I have no idea how long my first P&T hydrometer was inaccurate for and didn't find out it was off until one day when I was proofing and checked that the proof I had aimed for was correct and it wasn't. It might have been out for decades, but I'd always been happy with my products.

Now, I mostly use cheap sets of three that cover the range from 0-100%, check them for accuracy when they arrive, and don't get overly upset when I break one.

[Saltbush Bill]

I believe an Alcometer is a Proof and Tralle hydrometer.
Words.

Thanks all, i will test my p/t hydometer,
I only asked this because i read a while back they where not too accurate at lower abv, obviously not to be used to test a wash/mash after ferment for abv.

An alcoholmeter can only be accurate in a pure water ethanol mixture.
A wash or mash contains other substances which affect the density and a density based device like hydrometer or alcoholmeter will not be able to measure the abv directly.

And this is why it's best to refer to the one used for testing abv of distilled spirit as a Alcometer and the one for testing Wash , Mashes , ferments in general as a hydrometer........it saves this kind of confusion by distinguishing clearly between the two.

[Yummyrum]

I believe an Alcometer is a Proof and Tralle hydrometer.
Words.

Thanks all, i will test my p/t hydometer,
I only asked this because i read a while back they where not too accurate at lower abv, obviously not to be used to test a wash/mash after ferment for abv.

An alcoholmeter can only be accurate in a pure water ethanol mixture.
A wash or mash contains other substances which affect the density and a density based device like hydrometer or alcoholmeter will not be able to measure the abv directly.

And this is why it's best to refer to the one used for testing abv of distilled spirit as a Alcometer and the one for testing Wash , Mashes , ferments in general as a hydrometer........it saves this kind of confusion by distinguishing clearly between the two.

I’d agree with that Salty .But ….

A Hydrometer is a “Thing” thats buoyancy depends on the specific gravity of the medium it is suspended in . IE , how much it floats or sinks . All that is dependant on how much air is in it and how much weight is in the bottom of the bulb .

Hee hee , a boat load of fish caught at sea will float higher until it crosses the bar and enters the fresh water river .


This proportion of floatation is dependant on the “thickness” of a solution . The Thickness is called specific Gravity and is referenced to good old water at 20°C .
A specific gravity of 1.000

Clever people stick paper scales in them and calibrate them to give readings in all manner of situations .
It could be the salinity of a pool , the charge in a car battery , the amount of sugar( or other stuff ) in a fermenter or the percentage of Alcohol in a bottle . (Sugar addition for Liqueurs not included)
Then there is the Brix scale . It is all about how thick ( or thin) a Solution is .


So an Alcometer is technically a hydrometer by the method in which it measures ABV …. It floats ….well , compared to water , it sinks ) and is calibrated to read ABV

But , the label “Hydrometer “ is typically associated with “Beer/Wine Hydrometers “ which are used in the fermentation stage to gauge potential alcohol based on Original or start Gravity .( Actual beer ABV can be extrapolated when Final Gravity reading is taken . )

So for the purpose of clarity in the Forums , I’m with Salty that iff’n you are actually talking about an Alcometer , please call it that , as referring to it as a Hydrometer would conger up a Beer/wine Hydrometer.

Hiding now .

[greggn]

For running a still, accuracy isn't super important

+1

I'd rather it be "repeatable" than "accurate." I know my alcometer if off a bit but I also know how to use its reading to produce a consistent product.

[Reefer1]

Tbh, my question was really is it accurate to use on low wines, 20-30 abv. Or do i need to get a refractometer.
Point taken on using the correct terminology, i'm used to making wine, and the "alcometer" looks the same as a hydrometer,
Thanks

[Saltbush Bill]

, my question was really is it accurate to use on low wines, 20-30 abv. Or do i need to get a refractometer.

Accurate enough.
I've yet to come across one that wasn't close enough that it worried me.
Most are very accurate.

[dieselduo]

Brewing America has really accurate quality equipment. Try them

[Reefer1]

Noted diesel.

[shadylane]

Hey you guys.
Can i ask, how accurate are proof&trail hydrometers at lower abv's namely 15 to 30abv,
So my next wash i will be doing a strip run as advised by you guys, aiming for 25abv, i dont have a refracter, can i use my P/T hydrometer, will it be accurate.

Some great advice given already.

My 2 cents worth.
Cheap 0 - 100% PT hydrometers aren't very accurate, and get worst at the lower end of the scale.
Having said that, it's close enough for what you're going to use it for. That's watching closer for when you already know the prior runs needed to end around the same point on the scale. Just remember the low-wines proof recommendations are only a ballpark figure anyway.

When stripping a wash, I usually stop when the low-wines begin to get cloudy or oil appears on the surface. Have several smaller jars on hand at the end of the strip to see and catch the nasties before it can corrupt the majority of the low-wines.

[Reefer1]

Thanks guys, ye i dropped mine in some RO water at 15°c it was 2 points advanced.
My brand is stevenson/reaves i think scottish brand.
I need to get a spare, so i may look a little closer for a certified brand.
I have 2 wine hydrometers both read different by 5 points
Point taken though shady. Its ok for my application.

[NZChris]

Are you sure it was calibrated for 15C?

Certified hydrometers are very expensive and aren't really necessary for distilling except to keep the over-thinkers happy or for proofing spirits for sale if they are commercial.

[shadylane]

Thanks guys, ye i dropped mine in some RO water at 15°c it was 2 points advanced.

OWW shit, Ya shouldn't have done that.
Whatever you do...keep it quarantined, don't let another hydrometer near it.
Also try to keep it protected in a padded tube.
Every time, I've attempted to accurately check a hydrometer it eventually committed suicide.
One even rolled uphill and knocked a much more expensive PT hydrometer to its death.

Just pulling your leg, hydrometers don't do things like that.
None of them have mental issues and none of them are bashfull.
The kind that always turn their back on you so it's difficult to read the scale.

[NZChris]

I quite often have a glass on the bench with two or three alcometers and a glass thermometer in it when running.

My breakages have always been unrelated stupid stuff, like putting a hydrometer into a tube when both end caps are on the bench or knocking over a measuring cylinder that hasn't been glued onto an extra, wide, glass base.

[shadylane]

Those accidents could have been due to unhappy leprechauns.
In every stillhouse there's one or more that were born with a bad attitude.
It's best to only make small sacrifices.
Don't get carried away and spill too much, too often.
Just enough to keep the original leprechauns happy, but not enough to attract more.

Just like many things in distilling.
There's a fine balance that experience can sense but modern instruments can't measure.

[Saltbush Bill]

Having said that, it's close enough for what you're going to use it for.

Exactly , a point or two out ABV wise doesn't matter in hobby distilling, we don't need to keep Gubberments or anybody else happy like the Pros do.

The kind that always turn their back on you so it's difficult to read the scale.

I think ages ago Punkin over at Still Dragon had or was going to have Alcometers made with faces on all four sides , for the simple reason that he was sick to death of having them turn there back........the sooner this becomes common practice by manufactures the
F#@^in happier I will be....we have all been there.

I quite often have a glass on the bench with two or three alcometers and a glass thermometer in it when running.

Damn that's getting a bit geeky isn't it ?.......cant make decisions on senses alone ?
Then I saw this ....................

There's a fine balance that experience can sense but modern instruments can't measure.

[NZChris]

I quite often have a glass on the bench with two or three alcometers and a glass thermometer in it when running.

Damn that's getting a bit geeky isn't it ?.......cant make decisions on senses alone ?

When choosing heart cuts my decisions are on senses alone.

There is plenty to be learned from keeping records of what went into the jars that you selected the heart cut from, unless you know it all already, which I doubt I ever will.

[Reefer1]

he hee, these conversations crack me up.
Nice one shady, i accidently poked my self in my eye once with my wine hydrometer, gave myself redeye, i never broken one though, crap have i just jinxed myself.
Better get one ordered asap.
My alcometer calibration scale only goes down to 20 abv below that its anyones guess, mine reads +2 in water @ 15c adding the correction for 20 abv @15c + 2 makes it 4° out.
Callibrated to 20° c.
So i guess the alcometer is crap at measuring your mash post ferment ehh, so i gotta rely on the sugar scale on my wine hydrometer.

[Yummyrum]

So i guess the alcometer is crap at measuring your mash post ferment ehh, so i gotta rely on the sugar scale on my wine hydrometer.

Yes , totally the wrong tool .
Alcometers are calibrated to work in an Ethanol /water mixture only .
Fermented mashes and Beers , Molasses rum washes , fruit musts all have extra stuff in them .Fibre , Ash , residual starches or unfermentable sugars , all which make the mixture thicker or denser than if it just contained alcohol and water . It is these “extras” that cause the density to be higher and will make an Alcometer read incorrectly .

However a fully fermented out sugar wash that has been allowed to settle out clear will give an accurate reading of wash abv on an Alcometer .

[shadylane]

However a fully fermented out sugar wash that has been allowed to settle out clear will give an accurate reading of wash abv on an Alcometer .

Sounds logical to me.

I figure the accuracy would be better using something like a zero to 15% proof and tralles.
Thinking about it, there doesn't seem to be much info about measuring alcohol at lower abv%
Everyone is more worried about azeo.

On a side note....
Why hasn't anyone shared a DIY "floating" alcoholmeter build here?
Something meant for the lower end of the scale.
Can't be too difficult or maybe it is.

[Reefer1]

+1 Shady.
I was lookin around on Amazon and i seen a triple set each one calibrated for a third of the alc. Scale, i wander if that's the way to go, i know we don't need to be too finiky for hobby level, i just like to know this stuff.

[shadylane]

I hear Ya .
Think of it as measuring with a micrometer, marking it with chalk and then cutting it with an axe.