ABV Help

[ACarver]

First off, hello! Great to be on the boards.

My question is about cider abv after back-sweetening. I do Cider in 2 gal batches, and an abv of around 7%. I have used non-fermentable sugars before such as Splenda, but would like to try back-sweetening with apple juice concentrate and maybe brown sugar. I would use campden tablets and be stuck with flat cider (secondary question - is it any good?) since I have no kegging equipment at this time.

My question is once I find the abv, say 7% for the 2 gallons, can I figure out the final abv assuming no additional fermentation? Say I add about 20 additional ounces of fluid.

Thanks for any help, for some reason, I believe I am overthinking this.

 

[GinKings]

You'll need sorbate along with the campden.

Multiply original batch size times ABV and then divide by new batch size.

20 oz = 0.15 gallons

2 * 7 =14

14 / 2.15 = 6.5% ABV

 

[ACarver]

You'll need sorbate along with the campden.

Multiply original batch size times ABV and then divide by new batch size.

20 oz = 0.15 gallons

2 * 7 =14

14 / 2.15 = 6.5% ABV

Thanks for the quick feedback. That is what I came up with as well, just wanted to make sure I didn't miss something that wouldn't cause that to be true.

Also, what does that sorbate do?

 

[GinKings]

Before backsweetening, you want to get as much yeast to settle out as possible. Then, rack the cider to leave as much yeast behind as possible. Sorbate sterilizes any remaining yeast. Campden will not kill the yeast, but the sorbate works better when they are used together.

 

[completelyuncorked]

Campden is sorbate but at a weaker concentration. Campden will kill bacteria and weaken yeast but not kill it, sorbate will not kill yeast but it will halt its production thus stopping fermentation. Cold crashing will not kill yeast either. The best way to kill yeast is to pasteurize your bottles after they have carbed.

 

[GinKings]

Campden is sorbate but at a weaker concentration. Campden will kill bacteria and weaken yeast but not kill it, sorbate will not kill yeast but it will halt its production thus stopping fermentation. Cold crashing will not kill yeast either. The best way to kill yeast is to pasteurize your bottles after they have carbed.

Campden IS NOT sorbate. Campden tablets are a premeasured version of potassium metabisulphite.

 

[ACarver]

Thanks for the info. Another quick question, how long after the sorbate is added should I wait to bottle? I read that sorbate inhibits the growth of new yeast, but does not kill any living yeast cells. So how much longer should I wait (if even necessary) to bottle after the sorbate to make sure there are no bottle rockets?

Thanks!