Grain Mill recommendations and grain crush for Brewzilla Gen4

[RoomWithABrew]

Thanks RWAB I wasn't sure but sounds like a helpful option
Will look into getting some where is best place and how much should I use in a standard brew?

Well I just get mine mail order in NZ.
Typical addition roughly 2.5 – 5 mL for a standard 23 litre batch of beer. The enzyme is highly active from 40°C to 75°C (optimum 60°C) and from pH 3.5 to 6.5 (optimum 5.5), which is well within normal mash ranges. It is deactivated during the boil.

I would enquire at Murphys and Son probably only in big vols though, the homebrew shop I get break it down into 500ml or 100ml bottles. Perhaps Murphys would point you towards a brewer who uses it and they might put some in a bottle for you.
It's 4 pounds equivalent for a 100 ml so not much cost per batch.

 

[foxy]

REPORT
I have this afternoon done the mash and mash out for the brew with the grain bill that has the flour sieved out and the malt pipe lifted about a inch.
It went near perfect, the pump was run on full all the way through the mash and mash out with no issues or mash level lift from lack of drainage.
As a result the temp was as it should be and never varied more than 0.5 degree either way.
So to me it does seem as the grain crush is critical and the pipe lift gave me at least another litre in the void to play with.
The machine is a very good implement it just needs to find a way to get around the flow and drainage issue. My method was a bit drastic but I needed to prove that the main issue was mash flow/crush size which in my mind I believe or have convinced myself it is.
Now I have quite a few sacks of grain that has been pre-crushed and need to use it so looking at using Gluconase as suggested by Room with a Brew to help with mash flow.
Ps best place to buy Gluconase?

So with the flour removed, what was the efficiency? Next brew you should try it with the flour in, could just be the extra room that made a difference.

 

[The Baron]

Exactly what I am going to do and try a couple of other things too.
Eff has not been reported as I only mashed yesterday after work and I am just starting the boil this morning so will report later

 

[MashBag]

Hmm interesting.

Had you considered a beta-glucan rest at 40-45C for 30 minutes or so.

Or rice hulls?

This was a popular / regular conversation a million years ago on the braumeister forum.

 

[MashBag]

Murphy's supply Gluconase, but MM don't appear to stock it in a smaller volume. Given they do this for other Murphy products suggests to me that there is little or no demand.

 

[MashBag]

Would alpha galactosidase do similar? I don't know my enzymes well enough, but this is available.

Equally are we making this hard?
Have you considered testing full volume no sparge. That might also solve the issue.

 

[The Baron]

No it's got to be Beta from what RWAB said and as you have seen it is only available in large commercial quantities so it looks like a no go.
There is a old thread on the forum from a couple of years ago where a member went through the same and it has a limited storage life too so it was not really viable as large amounts and as you have seen none of the homebrew stores stock it probably for the same reason of having to split it down and storage also probably not enough demand

 

[The Baron]

So with the flour removed, what was the efficiency? Next brew you should try it with the flour in, could just be the extra room that made a difference.

Hi Foxy the BHE was 72% down slightly from 76% from the last brew which was the same grainbill, this could be due to having to stir it most of the time as the level kept rising and over running on mash time due to this too.

 

[peterpiper]

My BZ gen4 now has recirc mod. Giving split recirc, between inside malt pipe & outside malt pipe (via one lifting hole). This allows max flow at all times, even during the initial 15min grain bed rest.

Original recirc pipe goes to outer recirc, with valve usually left fully open. 2nd recirculation flow (pipe from drain tap) is to grain bed, flow being adjusted with drain tap. After rest, drain tap is set for max grain bed flow, without wort level in pipe rising (more than 1cm).
Maybe close down outer recirc valve a little, if faster grain bed flow is possible.

The total flow is now always either equal to, or greater than, the original system max flow. Which seemed limited by the recirc pipe diameter (rather than the pump). I'd say total flow, is now100% to 140%.
The 100% outer recirc, means grain bed temp can be maintained, without base temperature overshoots. And it help keeps any loose flour recirculating (till filtered out later, in grain bed after rest).


I can't see lifting the malt pipe, being helpfull.
If pump flow is greater than flow through malt pipe / grain bed. Lifting pipe, might just delay the pump running dry. But rather than solving the problem, might make it worse.

Poor grain bed flow, is likely due to a compacted grain bed. The effect of this, becomes worse where there's more flour.
Compaction is always going to be more of a problem, in systems with a tall & narrow malt pipe (rather than a broad & shallow pipe).
If the surrounding wort level (outside malt pipe), ever drops below top of the grain bed (& when level inside the malt pipe will be seen to rise), the bed is no longer 'floating' and will compact under its own weight, due to differential pressure.
That is the reason why 'fly sparging' keeps a floating bed, for good sparge flow rates.

Also, Graham Wheeler advises: at dough in, stir minimally, to just break up lumps, without knocking air from grains. Attached air increases grain buoyancy, giving a more open (less compact) grain bed.

Since doing mod; switching to gradual grain additions - a 1L jug scoop, with minimal stirring between; leaving a 15 - 20min grain bed rest (outer recirc only, while grain & flour hydrate); and absolutely no stirring after dough in, I've since, never have a stuck mash.

Previously I was doing a vigorous stir in, using a spiral drill paddle. Then stirring more every time it stuck.

My Weizenbock recipe (56% malted wheat which is huskless, so high in flour, but with 6% oatmeal husk addition), was previously a completely stuck, burnt flour disaster. With same recipe, but using the amended method, circulation & sparge now worked fine (though at only a medium-slow rate, through malt).

 

[foxy]

Hi Foxy the BHE was 72% down slightly from 76% from the last brew which was the same grainbill, this could be due to having to stir it most of the time as the level kept rising and over running on mash time due to this too.

It's the BHE that counts, 76% isn't shabby my last brew was 83% BHE but it was a simple brew, and my recovery of fermentable wort is excellent thanks to my Yorkshire genes passed on from my mother. My father's Irish genes help with the drinking.

 

[Vinylwasp]

Poor grain bed flow, is likely due to a compacted grain bed. The effect of this, becomes worse where there's more flour.
Compaction is always going to be more of a problem, in systems with a tall & narrow malt pipe (rather than a broad & shallow pipe)

I think you've nailed it, it's fundamentally a design flaw which is exacerbated by large grain bills (taller, and heavier) , and crushes with higher ratios of fine to coarse particles.

from Lauter Tun Design "One consideration in design is the height and width of the grain bed. If the grain bed is wide but not deep, water will flow through only a thin layer of grains and not much will be extracted. While a tall grain bed might therefore seem ideal, if the bed is too tall it actually will compact the grains resulting in lower extraction.

The rule of thumb for home-sized units is that the height to width of a vessel should be between 1:2 and 2:1 (John Palmer, How to Brew, Chap 17). For a cylinder this means your mash tun diameter and height should be about the same if it was filled to the top with grains. In practice often the height is a bit higher to account for deadspace and varying amounts of grain.'

 

[The Baron]

Hmm interesting.

Had you considered a beta-glucan rest at 40-45C for 30 minutes or so.

Or rice hulls?

This was a popular / regular conversation a million years ago on the braumeister forum.

Yes I have thought of a Bets-Glucan rest @45 but when I read one of the other members had done it made it worse so I may do it may not -jury is still out on it.
I used 200g of oat husks in the previous mash to this but it did not make any difference but that could be due to the over stirring.
So I am trying to improve the mash so Lots to try
45C rest + Oat Husks+Minimal stirring+ recirc-pipe down the side of the mash pipe and boiler side and no mash re-circ until 15 mins for the bed to settle and make sure the re-circ pipe is above the mash with a spray head on it to stop any channeling
Oh and the malt pipe lift I did will be done as a extra safety measure until I have found a way to get a consistent mash

 

[The Baron]

I think you've nailed it, it's fundamentally a design flaw which is exacerbated by large grain bills (taller, and heavier) , and crushes with higher ratios of fine to coarse particles.

I had already sussed that and anybody doing a large grainbill may suffer more as it is tall and slim so weight of grain will compress the bed I also think that is why a larger grain crush is needed with less flour plus hulls if essential.
The silicon pipe needs to have a spray head above the mash as it buries itself into the grain bed which can cause channelling adding to compaction and if you turn the pump off it can suck grain back into the pump and block ii.
I have ordered a grain mill so that in the future I can vary the crush to help this, the only issue is until I have used up nearly 2 sacks of pre-crushed I will have to be using all the methods in my arsenal

 

[The Baron]

Further to my last successful brew I have done a standard brew with no flour sifted out no oat husks so as i would normally do a brew.
I had the re-circ pipe put down the side of the grain basket and AIO side wall near where the built in temp probe is, I then mashed in with minimum stirring then left it to settle for 15mins.
I then re-circed with the silicon tube suspended 1inch above the mash and used a spray head so as to spread the re-circed wort.
It went near perfect again the mash temp was where it should be all the way through then mashed out @ 75c.
I did drop the heat down to 30% once it reached mash temp to stop major overshoots which it did.
So that is 2 great brews after a few teething problems and the BHE was 78% so it seems I have tamed the beast hopefully without tempting fate

 

[tondy79]

What kind of spray head are you using @The Baron ?

 

[The Baron]

A home made one nothing fancy, the reason I use one is that if you use the silicon tube and leave it free it will burrow its way down into the mash as it is like a jet washer coming out on full throttle so I coil it up and let it dangle above the mash with my home made spray head made out of a rubber bulb off a turkey baster with holes made in it.
I am playing with the idea of using a watering can spray head but I may have to enlarge some of the holes in case any grain gets in and clogs it but for now my homemade Heath Robinson works well.

 

[tondy79]

Sounds interesting! I've been using the top plate and laying the silicon tube on that, which seems to be doing me well but always interested to hear how other people are making things work!

Cheers!

 

[The Baron]

I never use the top plate as I think it may add to grain bed compaction

 

[gavp1979]

Further to my last successful brew I have done a standard brew with no flour sifted out no oat husks so as i would normally do a brew.
I had the re-circ pipe put down the side of the grain basket and AIO side wall near where the built in temp probe is, I then mashed in with minimum stirring then left it to settle for 15mins.
I then re-circed with the silicon tube suspended 1inch above the mash and used a spray head so as to spread the re-circed wort.
It went near perfect again the mash temp was where it should be all the way through then mashed out @ 75c.
I did drop the heat down to 30% once it reached mash temp to stop major overshoots which it did.
So that is 2 great brews after a few teething problems and the BHE was 78% so it seems I have tamed the beast hopefully without tempting fate

That's good to hear, I have a gen 4 and was considering trying the same thing on the next brew after hearing it on here (sorry I can't remember which member suggested it to give them thanks)

 

[gavp1979]

What kind of spray head are you using @The Baron ?

I was going to order the flexible hose and sergeant spray head from kegland but as usual life gets in the way and I never get round to ordering it, if I finally grab one I will let you know how it works. Or alternatively if any other members use the same arrangement l, shout up