After a long time brewing with not so precise measurement on the volumes produced, I decided to improve on this topic.

I thought about etching the BM Kettle but it would give some work which currently I do not have time to do.

So I thought about using the actual markings of the tie rod and a ruler.

It is known(If I'm correct) that the rod marks for the BM 50L are:

20L-25L-30L--45L-50L-55L

Knowing that i measured how many centimeters are between each mark, curiously I found out that between each 5L mark there are roughly 3cm and between the 30L and the 45L mark roughly 10cm.

So in between of 5L marks 1cm = 1.7L and in between of the 15L marks 1cm = 1,5L

I know that it is not 100% precise but using these measurements I assume I would be pretty close.

This weekend I brewed 50L of a american lager.

1) Using 11.5kg of grain(assumed a 0.6L/KG of grain absorption), I should reach exactly 48L before sparging = same as measurement(1,2cm below 50L mark)

2) With a 10L sparge I reached 58L(48+10), after a 80 minute boil(3.5L per hour boil off, 4.7 liters total) I should reach exactly 53.3L = Same as measurement(1cm below 55L mark, 1 cm = 1.7L)

3) I measured the trub loss with a pitcher, tipping the BM as much as I could and taking a bit of trub, ended up with 3L of trub.

4) Resulted in the exact 50L I planned and measured a 80% Ending Kettle Efficiency.

Does all of this makes sense?

I don't know why but it sounds to simple to be true...