Potential Alchohol and Sugar Additions

[renegade66]

A while back i made a spreadsheet that tracks the alcohol in my wine during fermentation as i enter SG readings along the way. This works great when i let a wine go to dry to the final SG readings and therefore the final alcohol.

I am trying to redo the spreadsheet to take into account sugar additions along the way in the fermentation but i am stuck at how the total alcohol is calculated.

Lets say i start with an OG of 1.080 and i let this ferment down to 1.024 which gives an Alcohol of about 7.00 percent. At this point i add enough grams of sugar to bring the SG back up to 1.080 and let it ferment back down to 1.00 what would the formula be for calculation of alcohol in this case.

In my original spreadsheet it work with no additions. i am dealing with a ginger wine i made with a OG of 1.100 but there were 3 additions of 500g of sugar along the way during fermentation. I took SG readings before and after each addition and the yeast died at 1.040 final SG. I know i cannot use 1.100 and 1.040 as the numbers to get total alcohol.

 

[Stressbaby]

It is proportionate to the total drop in SG.
1.080 -> 1.024 = 0.056.
1.080 -> 1.000 = 0.080.
0.080 + 0.056 = 0.136 -> 17.85% using ABV = (OG-FG)*131.25

 

[sour_grapes]

The problem is that the VOLUME also changes when you add sugar. You need to calculate how much alcohol you had at each step (which you can get by ABV*volume). Then divide the total alcohol by the final volume. Alternately, you could just use Fermcalc.

 

[renegade66]

The problem is that the VOLUME also changes when you add sugar. You need to calculate how much alcohol you had at each step (which you can get by ABV*volume). Then divide the total alcohol by the final volume. Alternately, you could just use Fermcalc.

I am adding in volume correction to my spreadsheet, slowly working out the required formulas. Since in my case i used sugar in grams, i am using 1kg of sugar is 0.63L in liquid volume. I downloaded Fermcalc and find it very useful. My spreadsheet is for tracking a fermentation with multiple daily readings that are graphed to show progress.

Likely too much info but i like all the data but its still a work in progress

 

[sour_grapes]

Looks very nice.

By the way, when I have included the change in volume, as referred to above, it has been a fairly small correction to the ABV. That is, IIRC, doing the calculation correctly changes the result only about 0.5% or less compared to the approximate method Stressbaby outlined above.

 

[DoctorCAD]

Or you could just guess that your ABV is around 14% and call it a day.

Wine is a relaxing hobby, why complicate it...JMO.

 

[renegade66]

Or you could just guess that your ABV is around 14% and call it a day.

Wine is a relaxing hobby, why complicate it...JMO.

Lol, this is my way of relaxing, I am an Electronic Engineer by trade The more sensors and readings the happier I am and the graphs i get allow
me to reproduce a batch when i want to without surprises.

 

[traveler94]

Lol, this is my way of relaxing, I am an Electronic Engineer by trade The more sensors and readings the happier I am and the graphs i get allow
me to reproduce a batch when i want to without surprises.

When I want to monitor my wine I take my turkey baster (wine thief) draw out an ounce from a carboy, sit in the silence and say to myself, what a wonderful thing.

 

[Graves]

A friend told me he added 10 pounds of sugar to 5 gallon batchs of wine. How much yeast would that require?

 

[Donatelo]

When starting my wine the SG was 1.110. At my last check it was .994 . Subtracting A from B gives me a reading of .126 which is 12.6% alcohol ? Correct?

 

[Ajmassa]

When starting my wine the SG was 1.110. At my last check it was .994 . Subtracting A from B gives me a reading of .126 which is 12.6% alcohol ? Correct?

No there's a whole math equation to figure it out. Just plug your numbers using a calculator like this https://www.brewersfriend.com/abv-calculator/

You've got yourself a 15.23% alc. by vol.

 

[cmason1957]

No, close, but no cigar. (Starting SG - Final SG) * 136 (and that 136 is sometimes a slightly different number). So in your case
1.110 - 0.994 = .116 * 136 = 15.8 % ABV.

I put your number into what I use all the time for this kind of calculation FermCalc, it gives 4 different answers 15.8, 15.8, 15.5 and 16.1.