Abv

[Cjacobs]

I have a question about abv. I know how to calculate before back sweetening but how do you calculate after back sweetening

 

[RPh_Guy]

Old ABV times old volume divided by new volume = new ABV.

 

[KaiB]

Old ABV times old volume divided by new volume = new ABV.

Assuming no further fermentation occurs...

 

[bracconiere]

Damn! how much are you back sweetening? i thought most people just added a cup or two of concentrate?

 

[GeneDaniels1963]

a cup of concentrate into 1 gal will change a 8% cider to 7.5%. Pretty significant change.

 

[bracconiere]

a cup of concentrate into 1 gal will change a 8% cider to 7.5%. Pretty significant change.

lol, 1 gram of ethanol in a 12oz drink is not note worthy to me....

 

[Cjacobs]

I put 1 concentrate in a gallon and a measured amount of honey looking for a flavor profile I let it run to 10%

 

[Maylar]

a cup of concentrate into 1 gal will change a 8% cider to 7.5%. Pretty significant change.

It'll also be awfully sweet.

 

[MarkKF]

My prob. is if I backsweeten with fresh juice after stabilizing I’m actually dropping the ABV. So 4 gal. cider plus a gal. fresh juice drops ABV 20%? i.e. 5% becomes 4%?

 

[RPh_Guy]

Yup!
5% ABV * 4 gal / 5 gal = 4% ABV

 

[Maylar]

Yup!
5% ABV * 4 gal / 5 gal = 4% ABV

What if the added volume also contains alcohol? Do you calculate the total alcohol and divide by total volume?
Example, topping off 116 oz of 13% ABV with 12 oz of 6.5% to make a full gallon (128 oz).

= 12.4%?

 

[RPh_Guy]

Use any blending calculator.
( ABV1 * Vol1 + ABV2 * Vol2 ) / ( Vol1 + Vol2 ) = final ABV

Yes, 12.4% for your example.

If ABV2 is zero, it simplifies to the equation I posted earlier.

Cheers

 

[GeneDaniels1963]

My prob. is if I backsweeten with fresh juice after stabilizing I’m actually dropping the ABV. So 4 gal. cider plus a gal. fresh juice drops ABV 20%? i.e. 5% becomes 4%?

Do a higher starting grav. by adding some sugar, or better yet, some FAJC. If you start with 7%, a loss of 20% would still leave you around 5.6%

 

[MarkKF]

That was just an example. Most of my juice starts at 1.054 and finishes at 1.004 so it’s around 6-1/2%