When I first bought my 50 litre BM, I made a measuring stick to accurately measure the mash volume. I 'calibrated' it against the markings on the centre rod using the 45 - 50 & 55 litre markings as my reference points.
From there I marked other volumes using the same measurements for each 1 litre and 5 litres on the ruler
Like this.
I've been using this for the better part of 3 years, thinking that it was accurate, because I assumed the the Braumeister markings would be correct.
Something I've thought of doing pretty much since I bought it, was to actually measure the amount of water going in and today I finally got around to it.
Today I measured 30 and then 50 litres into it. I tared the empty jug off on the scales and weighed 5 litres of water into it to make sure it was right.
Once I had the 2 volumes, I then worked out the rest of the 1 and 5 litre increments.
It seems that Braumeister markings in my BM are wrong and they're out by quite a bit.
What I discovered, for example, is that the 55 litre mark on the Braumeister is really only 53 litres and it gets considerably worse further up the ruler .
Below, the ruler on the left is the one I made today and the one on the right is the one I have been using for the last 3 years.
I only ever do full volume mashes and usually around 65 - 68 litres goes in.
If I'm right, it means that previously, when I thought I was putting 68 litres in, I was really only putting 65 in.
Interestingly my gravity readings are usually within a point or so and volumes are pretty close, though often short by a litre and a bit, based on Beersmith estimates.
Neither of those things have ever bothered me, but this has got me scratching my follically challenged head.
Has anyone else had this issue?
