This is a cut-n-paste from a member called `woozy`
=================================================================
Well, it's all a guess but flying by the seat of my pants:
Pounds of sugar to get 1% of alcohol boost = no. gallons/(6*attenuation of yeast).
So to raise a 5 gallon batch 1% with yeast attenuating at 75%, you should add 5 gallons/(.75 * 6) = 5 gallons/4.5 = 1.1111111.... = 1 1/9 lb of sugar.
(Because ... 1 1/9 lb of sugar in a gallon will rise the o.g. by 1 1/9 * 46 = 51.1111 pts. So in 5 gallons it will raise the o.g. by (1/5)* 5.1111 = 10.2222. This will raise the potential alcohol percentage by .131 * 10.2222 = 1.339% =~ 1 1/3%. But as the yeast has an attenuation of 75% the actual alcohol percentage will go up by 1 1/3% * 3/4 = 4/3 * 3/4 % = 1%)
(the 6 comes about because .131 * 46 = 6.026 =~ 6. .131 is the scale to convert points to potential alcohol, and 46 is the gravity points of a pound of sugar in 1 gallon of wort.)
=================================================================
going by what this guy says the 10 lbs of sugar alone potentially has 13.39 % ABV
the next batch that i do i'll try to remember to take a reading of the juice without adding the sugar.
Hope this helps
-Paps