How to calculate ABV when you add additional honey during primary fermentation?

[bolepa]

Hi ladies and gentlemen,
I remember I already read about this on this forum and even saved that discussion to certain location (folder/subfolder) in a "MEAD" section on one of my drives but cannot find it now.... Way too organized...
I cannot remember how to calculate ABV when you add additional honey during primary fermentation... My original batch was suppose to be three gallons but just because OG was too high I decided to make four gallons batch. OG was 1.110 for three gallons carboy and 1.120 for one gallon carboy. When SG in three gallons carboy reached 0.999 I added 8 oz honey. Now, when SG reached 0.999 again I would like to add some more honey to elevate ABV... but I don't now how to calculate the ABV now. Can you please help me? Thank you!
Here is more info in case if you need it:
Honey - 9 pounds and 3 oz
Concord grape juice - 1.5 gallons
Spring water - 1/2 gallons
Yeast : Lalvin 1116
TOSNA 2.0 protocol

 

[mac_1103]

I don't make mead but... Honey has about 35 PPG (points per pound per gallon). To calculate ABV you can just add those gravity points to the OG. It really doesn't matter when you actually added the honey to the fermenter. To be precise about it, you should account for the volume of the added honey as well.

 

[bolepa]

Thanks, mac! This sounds like an easy calculation....

 

[Maylar]

At 1.110-1.120 you're at 14-15% ABV already. You want more than that?

 

[bolepa]

At 1.110-1.120 you're at 14-15% ABV already. You want more than that?

I am OK with 15-17 ABV and I am perfectly fine with this as long as it ages for couple of years.... Personally, I would not go beyond 17% ABV but once again - this is my personal preferences... My point was how to calculate ABV after you add additional honey during primary fermentation...

​

 

[doug293cz]

I don't make mead but... Honey has about 35 PPG (points per pound per gallon). To calculate ABV you can just add those gravity points to the OG. It really doesn't matter when you actually added the honey to the fermenter. To be precise about it, you should account for the volume of the added honey as well.

Honey PPG can vary quite a bit depending on source, and other factors. If you are using the same honey for the original must, and the in-fermenter additions, then you can figure out what the proper PPG is. You need three data values from your original must:

1. Pounds of honey used to make the original must
2. Volume of original must after mixing with honey (not how much water you used to dilute the honey)
3. SG of the original must

The calculation is then:

PPG = Volume of Must * 1000 * (SG -1) / Weight of Honey​

​

You can then calculate the effective OG after adding additional honey with the following equation:

Effective OG = 1+ PPG * (Weight of Original Honey + Weight of Added Honey) / (1000 * Final Volume of Must/Mead)​

​

You then plug your effective OG into your favorite ABV calculator along with your FG. As always, the calculated results can be no more accurate than your measurements that go into the calculations.

Brew on

 

[mac_1103]

You'd think that by now I'd have learned not to post "quick and dirty" answers to math questions with that guy always lurking.

 

[bolepa]

Honey PPG can vary quite a bit depending on source, and other factors. If you are using the same honey for the original must, and the in-fermenter additions, then you can figure out what the proper PPG is. You need three data values from your original must:

1. Pounds of honey used to make the original must
2. Volume of original must after mixing with honey (not how much water you used to dilute the honey)
3. SG of the original must

The calculation is then:

PPG = Volume of Must * 1000 * (SG -1) / Weight of HoneyYou can then calculate the effective OG after adding additional honey with the following equation:

Effective OG = 1+ PPG * (Weight of Original Honey + Weight of Added Honey) / (1000 * Final Volume of Must/Mead)You then plug your effective OG into your favorite ABV calculator along with your FG. As always, the calculated results can be no more accurate than your measurements that go into the calculations.

Thank you doug! This is not that simple for me so I got break my brain a bit... Ha-ha!

 

[Maylar]

As another 'quick and dirty', you can say that a half pound of honey per gallon of must will add about 2.3% ABV on the average.

 

[bolepa]

As another 'quick and dirty', you can say that a half pound of honey per gallon of must will add about 2.3% ABV on the average.

Thank you, Maylar! This is much easier....
Everyone participated - my huge thank you to you!

 

[Snuffy]

You'd think that by now I'd have learned not to post "quick and dirty" answers to math questions with that guy always lurking.

Watching this, I had a flashback where I'm in the back of the class, shooting spitballs, and get called to the board to finish the algebra problem. After a couple of minutes of bluffing and head scratching, the kid with the tape on his glasses raises his hand...

 

[doug293cz]

Watching this, I had a flashback where I'm in the back of the class, shooting spitballs, and get called to the board to finish the algebra problem. After a couple of minutes of bluffing and head scratching, the kid with the tape on his glasses raises his hand...

I didn't wear glasses til I turned 40, but I had a trigonometry teacher in HS who seemed to delight in calling students up to the board to humiliate them when they didn't learn the material. She quit calling on me pretty early on in the school year.

Brew on

 

[Snuffy]

I didn't wear glasses til I turned 40, but I had a trigonometry teacher in HS who seemed to delight in calling students up to the board to humiliate them when they didn't learn the material. She quit calling on me pretty early on in the school year.

Brew on

No fun if you're prepared. Me too with the glasses. Seems like 40 was when the road signs all went fuzzy.

 

[hungupdown]

Calculations can give potential ABV. But the actual result depends on the yeast, and the fermentation conditions.

The vinolab chaptilisation calculator may help, but it's designed to work out sugar additions needed for thhe desired increase.