Brewzilla re circulation tube question

[Bogdweller]

Being new to this bit of kit ( only 2 brews in to date) on my first mash I used the top plate per instructions and the re circulation tube seemed to lay on the plate spreading the flow evenly until the plate sunk onto the grain in a a tight pack.
Reading on this forum that rice hulls and no top plate would help my second brew had no problem with the compacting grains but found the long tube just sank into the mash.
Does it matter how it recirculates, whether into or onto the grain?
Would shortening the tube so it pours on top of the mash be a thing to do if the wort needs to flow through?

 

[MrJay83]

I ditched the top plate as well. I try to angle the tube so that it's horizontal to the grain and kind of does a whirlpool on top (I seen a lot of grainfather and they do it that way).
I'm sure there's people that know a lot better than me but I would presume that you want the recirc to be spread as evenly as possible so you get an even distribution of heat in the malt pipe.

 

[Rodcx500z]

i use the top plate but not the overflow tube

 

[Bogdweller]

I ditched the top plate as well. I try to angle the tube so that it's horizontal to the grain and kind of does a whirlpool on top (I seen a lot of grainfather and they do it that way).
I'm sure there's people that know a lot better than me but I would presume that you want the recirc to be spread as evenly as possible so you get an even distribution of heat in the malt pipe.

That's exactly what I tried for the reason you state, it seems logical. It worked to a degree but I might try a modification of sorts to hold it in place as I felt it kept slipping down.
Cheers!

 

[Bogdweller]

i use the top plate but not the overflow tube

Hi!
Not sure what you mean by the overflow tube?

 

[Rodcx500z]

Hi!
Not sure what you mean by the overflow tube?

The adjustable tube that connects to the bottom plate in the grain basket i blanked it off and just use the top plate when recirculating

 

[H0PM0NSTER]

I've always used the top plate as it should help provide an even recirculation of wort during the mash and then for the sparge. Without it, i think you risk the wort forming channels through the grain and so not getting to all of the grain.

If you're concerned about the top plate compressing the grain, you could try fitting a spring clip to the overflow tube and resting the top plate on that. However, even though the grain does naturally compact during the mash recirculation, I've not had a problem sparging.

 

[MrJay83]

Without it, i think you risk the wort forming channels through the grain and so not getting to all of the grain.

That's why I try to get the wort coming out horizontally and get a good pool on top. My main reason that I stopped using it was that I was having stuck mash issues and fishing it out was a pain in the ****. I honestly don't think it's needed after doing a couple of brews without it.

 

[hoppyscotty]

You can still get channeling if the hose is horizontal, but you can see it and move the hose periodically. If you've not noticed a drop in efficiency then it probably not an issue, though the fact you're getting stuck mashes is more of an issue.

The top plate can be a PITA but if you are not getting stuck mashes then just a case of setting it in place and leaving it. I do think there is a useful function of the overflow pipe and you can see that in the new designs of the Grandfathers where they no longer have the overflow pipe but in stead have perforations up the malt pipe. Having that circualation of wort and additional mixing results in better consistency of temperature through the malt column and more precise temperature control. Though if you were to get a stuck mash I'm not sure how you'd spot it in the new Grandfathers...with an overflow pipe you can spot it easily.

I don't think there is an issue with the top plate sinking into the malt. Clearly when you set it in place don't push it in or down, but if it naturally sinks down its not an issue. Its is just sitting on top of the malt.

 

[Rodcx500z]

I use the holes for the handle to keep an eye on the level

 

[Benfleet Brewery]

I use both the top plate and the overflow tube but the overflow is only there just in case. I have the flow rate set so that there is a pool of mash water on top of the plate up to just below the top of the overflow. Water will follow the easiest path first but if you have a decent pool on top it is likely to be travelling throughout all the grains in the mash.

 

[hoppyscotty]

Not sure I believe that - and in the new Grainfather perforated malt pipes and even the mesh malt baskets in things like the Clawhammer Supply systems then this certainly is not a detrimental thing, which is counter intuitive, I know. And in any case after the first 20 mins or so of the mash you've extracted all the starch and enzymes out of the grains, so the remainder of your mash time is all about flushing the grains and the starch conversion that is happening within the wort. So even if some wort never sees the grains and just keeps going down the overflow tube the starch and enzymes are within the wort and the magic is still happening. It is far more important at that stage to have as precise control of the wort temperature and that is where the overflow helps.

But ultimately you will be getting a constant flow rate through the grain...that will occur irrespective of the flow rate into the top so you're always getting the same amount of wort passing through the mash wether you run overflow or not. The wort coming in will be mixing freely with the wort sat in the top inch or so, so the fresh wort coming in will not just be 'bypassing' the grain.

I've attached a bazooka filter to the top of my overflow pipe and push the tube down as far as it will go to promote constant overflow and and enable filtering of the wort and I have no issues with extraction or efficiency vs. running no overflow but temperature control is much more consistent.

 

[Bogdweller]

Thanks for your thoughts on this. Something to look at on my next session.

 

[RoomWithABrew]

Just beware that if you have the recirc tube in the mash and you turn the pump off you will get a siphon occurring.
This will suck grain up the tube and it can block it.
I suppose you could put a tea strainer type thing over the end of the tube to stop that occurring, but it would trap any particles that did get through the bottom of the malt pipe that you were recirculating to trap in your mash bed and filter.
Something to ponder.

 

[Bogdweller]

Fair point. Cheers!