Adding more sugar after fermentation is complete to boost alcohol - Home Brew Forums

 Home Brew Forums > Adding more sugar after fermentation is complete to boost alcohol

10-27-2011, 04:06 AM   #1
divi2323
Recipes

Oct 2011
Blue Island, IL
Posts: 376
Liked 13 Times on 12 Posts

I was considering adding more sugar to my cider so as to boost alcohol content. question i have is, does anyone have a way to calculate the finished ABV% in doing this?

I've taken OG and FG readings (1.052 down to .999) giving me about 7% alcohol. I wanted to bump it closer to 8 and wondered how much sugar to add. would I just bump the sugar content up so the hydrometer reads about 1.007 or 1.008 and then let it referment out a second time to 1.000 or am I underthinking this calculation a bit?

10-27-2011, 01:02 PM   #2
Docthorjp
Recipes

Aug 2011
Trois-Rivières, Québec
Posts: 15

I can not answer to your question precisely but when you add bottling sugar (250 g in 20 L) it will normally add 0.5% to your alcohol content. I "suppose" that if you add 250 g in your secondary and 250 g for bottling, you should be able to rise alcohol from 7 to 8 %. But this is just a supposition, it's not scientific!

10-27-2011, 10:35 PM   #3
GinKings
Recipes

Apr 2008
Bridgewater, NJ
Posts: 582
Liked 17 Times on 16 Posts

Sugar contains about 45 points of gravity per lb. One pound of sugar in a gallon of water will raise the gravity by 45 points. In a 5 gallon batch, it would raise the gravity by 9 points (45 / 5 = 9).

A drop of about 7 1/2 points of gravity is equal to approx. 1% ABV.

You want to raise your ABV by 1%, so you need to raise the gravity by 7 1/2 points. Multiply batch size (# of gallons) by 7 1/2. Divide by 45 and you'll get how many lbs of sugar to add.

It would be better to add the sugar prior to fermentation. Doing it post fermentation, you don't want to stir the cider and oxygenate it. I would dissolve the sugar in a small amount of water. Heating the water will make it easier. Then, add the sugar water to the cider.