Brewing math, a Belgian dark strong ale update:

Calculations are in!
Corn Sugar (Dextrose)
Yield: 100.0 %
Potential: 1.046
Color: 0.0 SRM
Max in Batch: 5.0 %

The estimated OG (Original Gravity) of my BDS Ale was 1.103. After having forgotton to add 1lb of Sucrose (table sugar) to the boil on brew day the actual OG rang in at 1.087.

A little brewing math is in order to figure out how much sugar to add in order to raise the SG (Specific Gravity) of the beer from 1.087 to 1.103.

Dextrose has a Yield of 100% meaning it is 100% fermentable, yeast will completely consume simple sugars such as dextrose, and sucrose.

Dextrose has the Potential of 1.046 p/p/g (points/pound/gallon), this means that for every pound of dextrose added to 1 gallon of water the specific gravity is raised by 46 points. the Specific Gravity of pure water is 1.000. Therefore:

(gravity points)(lbs of sugar)+(sg of water)=
(.046)(1)+1.000= .046+1.000= 1.046.

Now that we know what dextrose will contribute to our SG we need to figure out how much dextrose to add to reach our desired OG.

OG=1.087
Target OG (tOG)=1.103

First let's find out how many points we need to add, some simple subtraction will give us our points needed.

tOG-OG=Points needed or,
1.103-1.087=.016 or to simplify it further,
103-87=16

We need to add 16 points to achieve our target.

(GP)(lbs)/(gw)+OG=tOG

where: GP=Gravity Points, lbs=pounds of sugar, gw=gallons of wort, OG=Original Gravity, and tOG=target Orginal Gravity.

(.046)(2.125)/(6)+1.087=.009775/6+1.087=0.0162916+1.087=1.1032916 or 1.103

The total GP must be divided by the gw since the gravity contribution is points/pound/gallon.

According to the math 2.125 lbs of dextrose is needed to raise the SG to 1.103.