Newby questions re. mash deadspace and pump


Hi guys,
UK guy here - I’ve bought a BZ 3.1.1 and I’m still puzzling it out before my first attempt at a brew (downloaded instructions, youtube and google). I think I’ve got it covered (in theory! at least I’ll be brave enough to start…) but I have one question: it says on the robobrew website - for an older version - factor in x litres of dead space between tap and bottom. It says you can tilt, but you’ll get the crap if you do, so best to calculate 3 litres per kilo then add x litres for deadspace.
2 questions (well, 3 really):

  • I’m going to use the no-chill cube method and fill the cube(s) using the pump. I assume that is ok? i.e. to run boiling wort thru the pump? Second question - do I still need to factor in dead space, using the pump, or will the pump extract all the wort? And last question, I saw a video on Youtube which said you need to add 6 litres for the BZ 3.1.1 (on top of 3 litres per kilo) otherwise you may get a stuck mash, clogged pump. True?
    Any help gratefully received!




Hi Mike,
I have owned my Robobrew since January this year, and I’m still learning how to use it. During my first attempts I’ve had a couple of stuck mashes, but I think I have sorted that by using rice hulls until I get the crush right with my new grain mill. I have also blocked the pump once when I accidentally let some grain go down the central recirculation tube.

As far as your questions are concerned:
1/ I use an immersion chiller made from small bore copper tube, so have no experience of the cube method. However, there should be no problem running (near) boiling wort out through the pump . . . . But be sure not to let it run dry. This will not be easy to see because of the false bottom.
2/ The pump will remove most of the wort, but you may still need to experiment to get your volumes right. 3l/kg of grain plus 3-4l seems to work OK for me. However, I drain off my wort through the tap, and use a sieve to catch any bits of grain etc when I (gently) tip the vessel to remove (most of) the remaining wort. I don’t get too worried if I don’t get the required volume out. I measure the OG, and dilute the wort down with clean water if its too high. If its more or less right then I ferment what I’ve got.
I hope this helps.
PS - I used more water (+2l) in the mash when I made a Weizen recently because I was nervous of another stuck mash. However, that and 200g of rice hulls seemed to do the trick.