Foremost Brewing Forums

When it comes to the efficiency of the mash and lauter we want to know the pre-boil gravity.

There are actually two different original gravities (OG), the pre-boil or extraction OG and the post boil or pitching OG. It's important to realize the amount of sugar is constant, it's the concentration that changes depending on volume you collect.

It's easiest to understand this in the points "x"/pound "y"/gallon "z" unit of concetration.

When you mash you collect "z" amount of gallons of wort that has a gravity of "1.0xx" that was produced from "y" amount of grain.

To calculate your mash extraction in terms of ppg use this simple formula...

Multiply the number of gallons collected by it's gravity and divide by the amount of grain.

1.050(50) x 7.25gal / 11lbs = 32.95 ...or  50 x 7.25 / 11=32.95

We are shooting for a number somewhere around 30. 27 is ok, 29 is good and anything over 30
is great. Always try to improve your mashing technique and increase your brewhouse efficiency.

A great tip is not to lauter to fast, if your efficiency is somewhere between 25 and 28 this is most likely your problem.

Hope this helps
Cheers