Beer loss occurs during brewing startup, wort fermenting to beer process, from careless fobbing, overfilling, beer line leakages, bottle breakage . 
And beer loss often depends on the brewery scale and technical capacities.
So most brewers and brewery owner often calculate the beer loss before starting a brewery or pub.  

In the brewhouse, beer loss may occur at the wort stage as a result 
of over boiling and leakages or through incomplete wort drainage 
from spent hops and trub excluding normal evaporation loss. 
Fermentation losses depend on the type of fermentation and the vessel design 
as well as the method of yeast separation. 
Packaging losses might account for roughly 50% of the total production loss.


There is a basic estimated beer loss suggestions as below:
0.5% - 2% losses in Brewhouse during brewing process.
4% - 6% in Fermentation progress.
1% - 3% in maturation in brite tank or serving tank.There is also some loss on the way to maturation via centrifuges.
1% - 3% in Packaging and bottling.
So in total it can vary between 5.5% to 15%.
There are a lot of effective tools, practices and technologies available to reduce beer losses 
but first and foremost it is best to choose a high quality brewery equipment.
Sanitary and smooth inside contact of brewery pipeline, pump and tank can reduce beer loss during brewing and fermenting. 
Contact with brewman, we will turnkey a high quality and good performance beer brewing and fermenting equipment.