Expert: John Snyder - 9/12/2011

Question
During the fermentation process in beer,how can you relate sugar convertion to alcohol production? (noting the rate as well as the quantities) PLEASE HELP

Answer
1-- know the starting Specific Gravity ( O.G. )of the wort,before fermentation
2--take the Specific Gravity (final gravity ) at the end of fermentation

Calculation:

The amount of Co2 produced for every gram of ethanol produced during fermetnation is 1.05
Example:O.G. is 1.06 and the Final Gravity is 1.02.This means 0.04kg/L of Co2 has bubbled off.The alcohol content left behind is therefore:

1.05 x (1.06-1.02 )=0.042 kg./L to calculate the percentage of alcohol from here:
0.042/1.02=0.041 or 4.1%.this is the amount of alcohol by weight

Alcohol by volume:Weight of alcohol 4.1%/0.79=5.2%

Note: alcohol by volume is quoted on cans or bottles
 

a daily gravity check,can provide the rate of alcohol production, but that rate is dependent on fermenting temperature,and can vary greatly

Hope this answers your question,in a simplified explanation
         John