Brew Day Helper

matt_336px (62K)

These brewing calculators are meant to help me with my brew day endeavors. My friends wanted me to put this online since they said it helped them out. If you find any errors, please contact me at and I will fix the bugs as soon as I can. Also, if there are more calculations or another feature that you think would be helpful please email me and I will look into it.

If you don't want to use calculators and want to do all of your brewing by hand, you should check out my brewing notes for brewing without the help of software. Link to my brewing pdf notes

Batch Details
Boil Length: in minutes
Batch size: Gal L
Evaporation Rate: 10% an hour is a good start if you don't know
Mash Details
Temp of Grain:
Total weight of grain:
lbs kg
Water to grain ratio:
1.3 is a good start if you don't know
Mash Schedule
Acid Rest: 90-100F for 30mins
Protein Rest: 129-128F for 20-30 mins
Beta "Intermediate" Rest:
145-149F for 30 mins
Saccharification Rest: 150-157F for 30-60mins
Mash Out: 165-170F for 10-15mins


Temp °CTemp °FEnzymeBreaks down
40-45 °C104.0-113.0 °Fβ-Glucanaseβ-Glucan
50-54 °C122.0-129.2 °FProteaseProtein
62-67 °C143.6-152.6 °Fβ-AmylaseStarch
71-72 °C159.8-161.6 °Fα-AmylaseStarch
76-77 °C168.8-170.6 °FMash OutMash Out

FYI: α-Amylase quickly denatures above 78 °C (172.4 °F). Any starches extracted once the mash is brought above this temperature cannot be broken down, and will cause a starch haze in the finished product, or in larger quantities an unpleasantly harsh flavor can develop. Therefore, the mash-out temperature rarely exceeds 78 °C (172.4 °F).
Boil Length: in minutes
Evaporation Rate:
10% an hour is a good start if you don't know
Batch size:
Hop Additions
Bittering: 30-60mins
Bittering: 30-60mins
Flavor: 15-30mins
Flavor: 15-30mins
Aroma: 1-5mins
Aroma: 1-5mins

Fermentation Calculations
Original Gravity:     Temp:
Final Gravity: Temp:
SG Plato F C

Volume: L Gal
Temperature: C F
Desired CO2: Choose from table below. 2.5 is a good place to start if you don't know.

Volumes of CO2 for common styles :

Use the following list as a reference when entering the desired carbonation level. The typical range for each beer style (in volumes of CO2) is shown.


The "Temperature" is for the current temperature of the beer. This is used to calculate how much CO2 is already in suspension.
Also: Always add .2 volumes of CO2 to the recommended volume to make up for the carbonation lost at the tap.

Conversions Amount:


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