Calculate Stuff
While it's nice to know how to calculate things manually, a software program like Beersmith is easily worth twice it's cost and will save you a lot of time and frustration. For that reason, we are not listing every known calculation here, just the ones that come in handy from time to time.
ABV = Alcohol by Volume
FG = Final Gravity
OG = Original Gravity
DME = Dry Malt Extract
LME = Liquid Malt Extract
PPG = Points per Pound per Gallon
FG = Final Gravity
OG = Original Gravity
DME = Dry Malt Extract
LME = Liquid Malt Extract
PPG = Points per Pound per Gallon
ABV %
OG - FG * 131 = ABV
Example:
1.060 - 1.012 * 131 = 6.288 (or 6.3%)
Example:
1.060 - 1.012 * 131 = 6.288 (or 6.3%)
When adding DME or LME to raise the gravity, how much do I need?
Let's say your pre-boil gravity reading came to 1.060 but you were hoping to get to 1.070 and your pre-boil volume is 6.5 gallons. We can calculate how much extra DME or LME to add to make up the difference.
The easiest way to work with specific gravity is by using points. Simply drop the leading "1." from the specific gravity reading, and use the 3 digits after the decimal - so a specific gravity of 1.060 is equivalent to 60 points.
First, how many gravity points came from your mash?
Gravity x Pre-boil Volume = Total Gravity Points
60 x 6.5 = 390
Next, how many gravity points were we hoping for?
70 x 6.5 = 455
Finally, use the calculation below to find out how much to add considering that DME is worth roughly 44 PPG and LME is worth 38 PPG
(Gravity of Target - Gravity of Mash) / 44 for DME or 38 for LME = Amount to Add
Example:
(455 - 390) / 44 = 1.48 lbs of DME
The easiest way to work with specific gravity is by using points. Simply drop the leading "1." from the specific gravity reading, and use the 3 digits after the decimal - so a specific gravity of 1.060 is equivalent to 60 points.
First, how many gravity points came from your mash?
Gravity x Pre-boil Volume = Total Gravity Points
60 x 6.5 = 390
Next, how many gravity points were we hoping for?
70 x 6.5 = 455
Finally, use the calculation below to find out how much to add considering that DME is worth roughly 44 PPG and LME is worth 38 PPG
(Gravity of Target - Gravity of Mash) / 44 for DME or 38 for LME = Amount to Add
Example:
(455 - 390) / 44 = 1.48 lbs of DME