Brewing Formulas
- Wort-pot Original Gravity in terms of Carboy Original Gravity
- International Bitterness Units

Brewing Formulas

I like Math. I like Beer. This is some of the math you use while making beer.

The formulas below are implemented in the beer gem and a couple of scripts I have written which you can get here.

Wort-pot Original Gravity in terms of Carboy Original Gravity

$Graph$ is the volume of the carboy (or your fermentation container)

$Graph$ is the volume of the pot

$Graph$ is the measured original gravity (in platos - i.e. the 52 in 1.052)

$Graph$

International Bitterness Units

IBU is a measurement of the parts-per-million of isoHumulone in your beer. IsoHumulone is the isomerized alpha acid Humulone. Isomerization occurs during the wort boil. Read here for a more thorough discussion.

$Graph$ is the time the $Graph$ hop addition spent boiling

$Graph$ is the weight, in ounces, of the $Graph$ hop addition

$Graph$ is the alpha value (a whole number percentage) of the $Graph$ hop addition

$Graph$ is the volume of the carboy (or your fermentation container) in gallons

$Graph$

$Graph$ is an empirically derived model for utilization, which is described here.

This wikipedia page lists IBU values for common styles of beer.