Priming Sugar Fermentation Completeness - Home Brew Forums

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12-21-2012, 09:11 PM   #1
Semsem
Recipes

Dec 2012
Posts: 7

Question is rather simple, however I've been unable to get an answer through online searching.

Does all of the priming sugar get consumed by the yeast during bottle carbing?

So, if you had, 10 grams of sugar in the bottle, would one expect that when the bottle is ready and properly carbed up, that it would contain none of the 10 grams of sugar?

I've read that 2.0665 grams of 'extract' produced 1.00 grams of alcohol, and that it doesn't matter what the extract is (sucrose, glucose, etc.) it's always the same.

Which in this case leads me to another question, if one had enough priming sugar for 8 grams (of sugar) per cup (of liquid), that would produce 16.532 (8*2.0665), which then would be 0.7 ABV (16.532/236 grams per cup of water), correct?

But that somehow makes me question the whole bottle carbing only adds max of 0.5% ABV for any bottle carbing (including what I've read about Soda).

Any help would be appreciated to help explain to me where I've gone wrong in my math/thinking.

12-22-2012, 03:10 AM   #2
Kaiser

Recipes

Nov 2005
Pepperell, MA
Posts: 3,895
Liked 133 Times on 76 Posts

Quote:
 Originally Posted by Semsem Does all of the priming sugar get consumed by the yeast during bottle carbing?
most priming sugars are simple sugars and the yeast should be able to consume it all. There might be exceptions, but for the most part the answer is "yes".

Quote:
 So, if you had, 10 grams of sugar in the bottle, would one expect that when the bottle is ready and properly carbed up, that it would contain none of the 10 grams of sugar?
Yes. But be careful, some sugars are not all sugar. The corn sugar we are using is actually dextrosemonohydrate (1 dextrose molecule + 1 water molecule combined) and thus only 90% of its weight create alcohol and CO2

Quote:
 I've read that 2.0665 grams of 'extract' produced 1.00 grams of alcohol, and that it doesn't matter what the extract is (sucrose, glucose, etc.) it's always the same. Which in this case leads me to another question, if one had enough priming sugar for 8 grams (of sugar) per cup (of liquid), that would produce 16.532 (8*2.0665), which then would be 0.7 ABV (16.532/236 grams per cup of water), correct?
8 grams make 4 grams of ethanol which is 5 ml ethanol. Added to 237 ml this is 2% ABV. I think you ended up multiplying the 8 g by 2.0665 to get the amount of ethanol. You need to divide. And don't forget about the density of alcohol.

Quote:
 But that somehow makes me question the whole bottle carbing only adds max of 0.5% ABV for any bottle carbing (including what I've read about Soda).
most bottle conditioning adds about 0.003 to you sg and thus increases the effective OG of the beer by 0.003. This causes an ABV increase of ~0.25

Soda making is different. There you stop fermentation. Depending on when you stop the fermentation you will have less or more alcohol and carbonation.

Kai