Alcohol By Volume:
ABV = (Original Gravity - Final Gravity) x 131
Alcohol By Weight:
ABW = (0.79 x ABV) / Final Gravity
Degrees Plato:
Plato = (-463.37) + (668.72 x Original Gravity) - (205.35 x (Original Gravity ^ 2)
Here is an example using 1.040 for Original Gravity...
(-463.37) + (668.72 x 1.040) - (205.35 x (1.040 ^ 2) = 9.99224 or 10 Plato
Calculating Real Extract:
Real Extract = (0.1808 x Plato Original Gravity) + (0.8192 x Plato Final Gravity)
Here is an example using an Original Gravity of 1.040 and Final Gravity of 1.010. Determine Plato for each gravity with above degree Plato formula and then punch then into the formula:
(0.1808 x 9.99224) + (0.8192 x 2.559665) = 3.90347456
Calculating Calories per 12oz bottle of beer:
This will calculate calories on a 12oz bottle of beer.
((6.9 x ABW) + 4.0 x (Real Extract - 0.10)) x Final Gravity x 3.55
I prefer ml's instead of oz's myself, and I use larger bottles than the 12 oz. So for my 500 ml and 1000 ml I change the above formula. If you remove the 3.55 at the end of the formula it will give you calories per 100ml of beer. Then just multiply that by the size of your bottles. Here is an example using a 500 ml beer:
((6.9 x ABW) + 4.0 x (Real Extract - 0.1)) x Final Gravity x 5 = Calories per 500ml of beer
If your using oz but your bottle is larger than 12oz use the below formula . Here is an example using an Origin Gravity of 1.040 and Final Gravity of 1.010.
((6.9 x ABW) + 4.0 x (Real Extract - 0.1)) x Final Gravity x 29.573 / 100 * Bottle size in oz = Calories per ??oz of beer
Example: ((6.9 x 3.074) + 4.0 x (3.090347456 - 0.1)) x 1.010 x 29.573 / 100 * 16 = 174 Calories per 16 oz beer
Calculate IBU's & SRM's:
International Bitterness Units (IBU):
((Alpha Acids AA% x Quantity in oz's) x % Utilization) / 7.25
Multiply Alpha Acids of the hop by the amount of hops you are using. Then take that calculation and multiply it by the total utilization based on the amount of time you plan to boil these hops. Take that calculation and divide by the constant 7.25 to get your final IBU.
Utilization Chart: Percent Utilizations 00-05 minutes 5.0% 06-10 minutes 6.0% 11-15 minutes 8.0% 16-20 minutes 10.1% 21-25 minutes 12.1% 26-30 minutes 15.3% 31-35 minutes 18.8% 34-40 minutes 22.8% 41-45 minutes 26.9% 46-50 minutes 28.1% 51-60 minutes 30.0%
Example: ((8.8 AA% x 0.75 oz ) x 30) / 7.25 = 27.31 IBU's
Standard Reference Method (SRM):
(Lbs Grain x Deg Lovibond) / Total Volume in US Gallons
So if you used 10 pounds of 2 row grain that is 1.9 Lovibond then you would multiply lbs of grain by Lovibond to get your SRM. Then add all the SRM's and divided by total batch volume by total US Gallons. Here is an example below:
(10.00 Lbs Grain x 1.9 Lovibond) = 19.0 SRM's
(0.50 Lbs Grain x 10.0 Lovibond) = 5 SRM's
(19 + 5) / 5 gallons = 4.8 SRM's
Hydrometer Temp Correction:
T1 = Temperature Deg F
T2 = Temperature Deg F
T3 = Temperature Deg F
NOTE: ^ means "to the power of"
Temp Correction = 1.313454 - 0.132674 x T1 + 2.057793 x 2.71828 -3 x T2 ^2-2.627634 x 2.71828-6 x T3 ^ 3
For below result a .0006 is the correction to be added to your OG. So for example if you had an OG of 1.030 you would have 1.0306. I would then round up to 1.031 for my final OG temp corrected.
Example: 1.313454-0.132674 x 64.4 + 2.057793 x 2.71828 -3 x 64.4 ^2-2.627634 x 2.71828-6 x 64.4 ^3 = .0006
If you're like me and you use Degrees Celsius then just multiply temperature by 1.8 and add 32. Here is an example below of the changed formula:
1.313454-0.132674 x ((64.4x1.8)+32)+ 2.057793 x 2.71828 -3 x ((64.4x1.8)+32) ^2-2.627634 x 2.71828-6 x ((64.4x1.8)+32) ^3 = .0006
Predicting Original Gravity:
(Lbs of grain x points) / Total Volume in Gallons
So for this calculation let say I'm using 2 row pale malt with a gravity of 1.030 which would be gravity 30 points. Take the amount of pounds of grain and multiply it by the gravity points then divide by the total volume in gallons. Here is an example below:
(10 lbs of grain x 30 points) / 5 us gallons = 60
To convert this 60 back divide by 1000 and add 1 so 60 would be 1.060. What I do on my brew sheet is add the gravity for each grain then divide that by the total volume in gallons.
(10 lbs of grain x 30 points) = 300
(5 lbs of grain x 10 points) = 50
(300 + 50) / 5 US Gallons = 70 or 1.070
Determine Priming Sugar Required For Carbonation in grams:
T = Temperature at bottling in degrees F
15.195 x Volume in Gallons ( Desired CO2 Volume - 3.0378 + .050062 * T - .00026555 * T * T )
For Desired CO2 Volume I usually check what the range is on that style of beer. For example an American Ale CO2 volume is between 2.2-2.8. I usually take a number between that range and plug it into my formula. For a list of CO2 volumes for each style of beers try this site.
Example: 15.195 x 5 ( 2.4 - 3.0378 + .050062 * 64.4 - .00026555 * 64.4 * 64.4 ) = 113 grams
Apparent / Real Attenuation:
Apparent = (Degrees Plato Final / Degrees Plato Start) - 1
or
Real = (Real Extract / Degrees Plato Start) -1
This measures how much of the sugars has been fermented in to alcohol... I show this number as a percent in my excel sheet.
Mash Water:
Mash Water = Mash Ratio x Lbs Grain
For the mash ratio you can use between 1-2 quartz per pound of grain. Keep in mind that changing the ratio can have a direct impact on what kind of beer you will end up with. For example:
Less than1.25 Quartz per lb of grain: - Less fermentables - Sweeter - Malty / More body
greater than 1.25 Quartz per lb of grain: - More fermentables - Drier - Less body
So here we will use 1.3 quartz of water per pound of grain...
1.3 x 10 lbs of grain = 1.3 Quartz of mash water
Absorption Loss:
(lbs of Grain) x 0.20) = Absorption loss in gallons
Note each system can be a little different and therefore may use a different constant than 0.20 gallons per lb of grain.
Total kettle Wort:
(Mash Water - Absorption Loss) + Sparge Water
Evaporation Rate (10% / hr):
Pre-Boil Wort * 0.10
The constant of 10% per hour can be different in every system. This can be a range from 6-15% depending on your equipment. To figure out exactly you can do a test boil and measure the amount of water left after the boil. So if you start with 10 litres of water and finish with 9 after one hour your evaporation rate would be (10-9) / 10 = .10 or 10%
Evaporation Loss:
(Evaporation Rate / 60) x Total Boil Time
Cooling Loss:
(Total Kettle Wort - Evaporation Loss) x 0.04
You will lose 4% volume do to cooling/shrinkage loss based on the fact that the liquid will lose density when cooling.
