Measuring %ABV of sweetened spirit

[azmotard]

I am tryong to find a precise way to measure the %ABV of Lemoncello that I am making.

I understand that an Alcholmeter or proof hydrometer can measure the %ABV of a spirit but only before flavors or sugars are added. Is there a way to accuratly meaure the %ABV once the spirit has been flavored and sweetend.

Some one mentioned that it could be done with a refractometer but I've not been able to find details on how to use one to do this measurement.

[AllanD]

There are hydrometers that measure alcohol content in water/alcohol solutions

There are also hydrometers that measure sugar content.

As far as I know there is no hydrometer that will measure sugar or alcohol accurately when the other is also present.

sugar screws up the readings of an alcohol hydrometer
and alcohol screws up the reading of a sugar hydrometer.

There are tables that allow you to add sugar syrup of a known concentration to alcohol of a known proof and get a predictable reading...
Those tables are usually found in Liqueur receipe books...

AllanD

[stoker]

it should work with a hydrometer, and then do some calculations (if you already know the sugar content)

[hornedrhodent]

="azmotard"


I understand that an Alcholmeter or proof hydrometer can measure the %ABV of a spirit but only before flavors or sugars are added. Is there a way to accuratly meaure the %ABV once the spirit has been flavored and sweetend.

I measure the a/v of my spirit and calculate what volume of water is required to bring it to the desired a/v. Adding sugar to the water used make up this volume wont change the a/v but will change the hydrometer reading.

I imagine it would be possible to work this backwards but you'd have to know the a/v of your spirit.

[azmotard]

Thanks for ther input. I'll try and find the tables mentioned above and try and post something.

Here is a follow up question. Will the flavorings offset the reading to any great degree?

[stoker]

depends on what you mean with flavours, but the influence will not be as be as the one of sugar. but it will influence the reading, but most certainly not a lot

[markx]

Hydrometers register the density of the solution that they are soaked in. So everything that affects the density will also affect the reading.

[Grayson_Stewart]

The easiest way to do limoncello is to measure the alcohol percentage before you perform the maceration on the lemon peels. Keep up with all the volumes used and make a final hand calculation of the alcohol percentage of the limoncello based on the original percentage and total volumes used.

[possum]

Yep... just like grayson said.
You must know the proof of spirit and initial volume.
Then compute the volume of 100% abv present.
Find the final volume of the lemoncello.

vol of 100% Alcohol / total volume of end product = %abv


Sugar makes an alcoholmeter give funky results when sugar and spirit are together.

[erlendurh]

You must know the proof of spirit and initial volume.
Then compute the volume of 100% abv present.
Find the final volume of the lemoncello.

vol of 100% Alcohol / total volume of end product = %abv

I know this is an old thread but just to be sure if I understant this correctly

vol of 100% alcohol if I have 1000ml of 96% abv alcohol os 960ml ?
is that correct possum or Grayson or anyone else with the correct understanding of this

If this is correct and I have 960 ml of 100% alcohol and I add 960ml of anything as long as there is no alcohol in it then I get 96%/2 = 48% abv?

or if we use possums equation we have 1000ml liquid that is 96% abv so we have 960ml of 100% abv and we like to add 1500ml of syrup to it then we get an abv of 960ml / (1000ml + 1500ml) = 0,384*100 = 38,4% abv

I sure hope I am understanding this correctly
I was just confused about how to calculate this volume-of-100%-abv in the equation

cheers Elli

[still_stirrin]

I know this is an old thread but just to be sure if I understant this correctly

vol of 100% alcohol if I have 1000ml of 96% abv alcohol os 960ml ?

yup.

If this is correct and I have 960 ml of 100% alcohol and I add 960ml of anything as long as there is no alcohol in it then I get 96%/2 = 48% abv?

yup.

...or if we use possums equation we have 1000ml liquid that is 96% abv so we have 960ml of 100% abv and we like to add 1500ml of syrup to it then we get an abv of 960ml / (1000ml + 1500ml) = 0,384*100 = 38,4% abv

yup.

[Hound Dog]

vol of 100% alcohol if I have 1000ml of 96% abv alcohol os 960ml ?

Yes. That is why you never have 100% alcohol out of your still. It is 96% alcohol.

[Kareltje]

So you can not measure the %ABV of a sweetened spirit, at least not by measuring the specific gravity.
Calculating of the %ABV alcohol and the %ABW sugar is possible, though.

But that was not your question.

[erlendurh]

yup.

Thanks SS for that eloquent confirmation

thanks guys

[Kareltje]

In all these calculations the contraction of alcohol and water is neglected.
For what it is worth: I once made a small model for making ouzo with specified %ABV alcohol and %ABW sugar.
Do not know if I can post it here.

Edit:

So yes, I can.
The specific gravities of alcohol, water and dissolved sugar are in G2 to G5.
The distillate you have at hand you put in C2 and C3, the available amount of alcohol is calculated in C4: C2*C3/100.
The percentages alcohol and sugar you wish you put in C6 and C7.
The amount of drink you get, the amount of sirup you have to add and the amount of sugar in that sirup are calculated in C9 to C11. The trick is, to dissolve the amount of sugar in a little water and then put this sirup and enough water in the distillate.

The formulas for the calculations are in H9 to J19.

The block B14 to F19 is to check the calculations.
The reasoning is as follows: first you calculate the volume of alcohol and non-alcohol to get the right %ABV. In the non-alcohol is water and sugar. When you want to add one gram of sugar you have to take out 1/1,616 ml of water (Note: the comma is the decimal comma!!)
Knowing this you get the formula for C11: (C7/100)*(C9*((C6/100)*G2+1-(C6/100)))/(1-(C7/100)*(1-(1/G4)))

To prevent mistakes in typing you could do Ctrl-C , Ctrl-V.

Note: I did not take into account the contraction of alcohol and water upon mixing them. So the outcome is not exact.