mm for grain crusher - where to start?

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andypatt

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Hi all,

I've recently bought a grain crusher and have set it up ready for my brew day this weekend. I know I'm going to have to dial in the crusher for my particular setup (35L brewzilla) but I was wondering what I should start with?

The gradent goes from 0.64-2.41mm. The exact crusher is a brewferm grain gorilla like this: Brewferm Grain Gorilla Malt Mill With Adjustable Stainless Steel Rollers - Get Er Brewed

Any help much appreciated!
 

Clint

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I know nothing of such things! But..."the width of a credit card" seems to pop up quite regularly.
 

Brew_DD2

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Hi all,

I've recently bought a grain crusher and have set it up ready for my brew day this weekend. I know I'm going to have to dial in the crusher for my particular setup (35L brewzilla) but I was wondering what I should start with?

The gradent goes from 0.64-2.41mm. The exact crusher is a brewferm grain gorilla like this: Brewferm Grain Gorilla Malt Mill With Adjustable Stainless Steel Rollers - Get Er Brewed

Any help much appreciated!
I got the same one and just fiddled about until I was happy with the crush. I settled at about 1.14 but YMMV.
 

phettebs

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I know nothing of such things! But..."the width of a credit card" seems to pop up quite regularly.
That's exactly what I use. I used to use a gapping tool but lost it at some point. I took mine all apart to clean it a month back. I gapped it with a credit card and it's working just fine.
 

andypatt

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Thanks for the replies folks! I'll have a test this weekend - I have some crushed grain leftover from GEB I used to use so can have a visual look.
 

Hanglow

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For malted barley I typically use 1.2mm . That's fairly wide (I think), I do step mashes and recirculate with a 2 vessel system and get good conversion and clarity from the mash. I wouldn't go lower than 0.8mm, that would be pretty fine. Although some do

Some barley varieties are different sizes, so sometimes it helps to test a bit too. Also things like wheat and rye really need milled separately as the grain sizes are different again
 

An Ankoù

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Mine arrived from Geterbrewed last week (12% off, a bargain). there are no instructions as to what settings to use so I went a bit finer than midway and set it at 1.4 mm. The crush seems a tad finer than my commercially crushed grains and the beer I made with it this morning seems to have worked fine. But, I don't use an all-in-one system and I don't know if that required a particular crush.
 

Hop_it

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I use the 35l Brewzilla, and had a lot of problems when I first got it with ready milled grain because the wort circulation was very slow through the grain bed, and it was difficult to maintain the mash temperature (i.e. the temperature of the grain bed, not the liquid at the base close to the heater and the thermocouple). I invested in a "Grain Gorilla" from GEB about 9 months ago, and have tried various different mill roller gaps (from ~0.8mm up to 1.4mm). I have had my best result so far using a gap of 1.2mm with moisture conditioned grain. The crush was not dusty, and the efficiency and extraction were both good. I achieved a satisfactory wort flow through the grain bed, and the mash temperature remained very stable (although I do use some additional insulation around the outside, and on the pipework - see: The Dummies' Guide to Brewzilla).
This experiment was based on a grain bill of ~5kg and a strike water volume of ~20l, which gives a very fluid mash. However, based on experience to date this seems to work best with the Brewzilla. I seldom brew high gravity beers, so I have no idea yet how well it will work with a really big beer?????? You can use more strike water, but this leaves a lot less for sparging. I suspect that the efficiency will drop, and it might be more difficult to achieve a satisfactory mash pH because of the additional dilution of the mash. . . . . . But that's a challenge for another day 🤞
 

An Ankoù

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With no disrespect intended to those who use all-in-one systems, they do seem more than a little temperamental. Apart from saving space, do they really offer advantages?
 

Cheshire Cat

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With no disrespect intended to those who use all-in-one systems, they do seem more than a little temperamental. Apart from saving space, do they really offer advantages?
AA you're opening the 3 vs AIO debate again. As I've said before an AIO system uses 3 vessels so no space saving.
 

Hop_it

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Sorry CC. I hadn't realised that. I thought AI1 meant what it said, but as I've never used one, I'll shut my fat gob. 🤐
First of all, no offence taken. I have owned my Robobrew/Brewzilla for nearly 18 months now, and I have asked myself that question several times 😩 However, having spent ~£350 on it I was determined not to be defeated, and I wanted to be able to use some of the apparent advantages, i.e. programable timers and the ability to step mash.
I'm not a prolific brewer, but I have been brewing the traditional way for a very long time. So, perhaps it has taken me longer to get the measure of it than many others who brew more often than me. But you are right - they are temperamenta,l but only in so much as you have to adapt your processes in order to get the best out of it. There were no instructions or guide to best practice in the box, so I have had to use a methodical approach, and learn by trial and error, or by picking up ideas and tips on forums such as this.
As for "space saving" I (mostly) agree with Cheshire Cat. You still need a hot liquor tank, but the rest of it (boiler and mash tun) are either inside each other or stacked when in use. But you still have to clean it all. However, it packs away very neatly, so theoretically that saves some space . . . . . But I have still kept my old mash tun and other bits of kit, so in reality there is no space saving.
Would I buy it again? . . . . . Probably, because I can still see some advantages - despite a lot of frustration and cussing 🤬
 

Slid

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For a long time I blamed my failures on the GF on too fine a grain crush from the pre-crushed grain that all the HB suppliers sell.
In the end I bought a grain mill (Bulldog) and after many errors, ended up with the credit card test - if you can just insert a "punched" credit card - with raised letters - and turn the mill by so inserting, the gap is perfect. By some bizarre coincidence, the grain looks remarkably like the crushed grain from the HB suppliers. Probably pretty much the same crush, in fact.

As my much loved GF has not gone past 80C without cutting out for many a long seeming time, my "A-I-O system" involves not only a sparge vessel, but using the same, a PECO boiler, for the boil itself, and two wort transfers, one via a BIAB bag, to and from the GF itself.

So, why not just get a 3 vessel in the first place?
 

Oneflewover

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I can't remember what my mill's roller gap is, probably a bit narrower than credit card width. I set it yonks ago and it suits me fine. However I condition my grain and I honestly think this has been a game changer in terms of a good recirculation and lauter on my all-in-one
 

Philthebrewer

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Hi Andypatt, welcome to the semi-predictable world of Brewzilla and its missing documentation (thanks for the guide. After much trial and error I have settled on a 1.1mm roller gap (which I measure with a spark plug gap tool). My grain mill is a cheap one and tricky to adjust correctly so that it is the same gap both sides, so I just leave it like that regardless of whether I mill barley or wheat. Most of my grain is cracked but not broken, which is just how I want it.

I tend to go for as wet a mash as possible, using 25l of starting water and then adding between 5 and 5.5kg of grain depending on what I brew. This means I only need to stir the mash every half hour. The big improvement for me was the addition of a small handful of rice hulls. I don't know why they work so well, but they just do. I am still left with around 6 or 7 litres of sparging to be done if I want to get to a 23 litre ferment, so I don't think I am missing out on OG in the leftover mash. My brewhouse efficiency as measured in beersmith is normally around 75%, which seems comparable with my other kit, a braumeister 23l.

I now find it best to work "with" the brewzilla rather than getting annoyed with it. One big advantage is that it is pretty easy to clean up and the pump (so far) has only stuck once and that was due to my error in letting grains into it from the top. Enjoy.
 

dcbrookes

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I abandoned my Brew Monk after a frustrating year, and now use it just as a programmable boiler with pump. The biggest problem I had with it was unwanted tannin extraction, and I tried just about every setting without much luck. I am sure this was caused by the wort being overheated during the circulation process, even at the lowest power setting. I also found the grain tube hard to lift, as I work in a conservatory with limited head room; there were other irritations as welI. I have now gone back to using a double insulated SS mash tun from Angel Homebrew and am much happier with the results.
 

Hop_it

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I can't remember what my mill's roller gap is, probably a bit narrower than credit card width. I set it yonks ago and it suits me fine. However I condition my grain and I honestly think this has been a game changer in terms of a good recirculation and lauter on my all-in-one
Out of all of the things that I have tried I also believe that the grain conditioning has made the biggest improvement to the wort circulation. It appears to be the difference between crushing dampened grain (almost no dust) and grinding dry grain (lots of dust). Even before contributing to this thread I had decided that for my next brew I would try a smaller mill roller gap, perhaps ~1.0mm (which is easy to set with feeler gauges), but still condition the grain . . . . . we'll see what happens 🤔
I also tried using rice hulls (ref: Philthebrewer) in a wheat beer because I was concerned about the likelihood of a stuck sparge. However, it was before I started milling my own grains, so I had no control over the crush etc . . . . . But they certainly helped :thumbsup:, and I would definitely use them again in similar circumstances.
 

andypatt

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Thanks for all the info!

I tried it this weekend at 1.14 from the first suggestion and got a stuck mash even with 100g of rice hulls - unfortunately lost efficiency (aiming for 6.9% and got 6.3%) - although it was a big grain bill and had to remove some of the water once I put the grains in - I think I just tried to brew too much for the kit!

Lesson learnt from this weekend - don't try and do too many new things at once (Big Grain bill, New Brew Space, Milling own grain) so you can't diagnose which gave you issues.

On the convo of Brewzilla/AI1's and 3VS's, I've done maybe 10 or so brews now on my Brewzilla and really think its brilliant - definitely made brewing simpler and less mess, and beers have dramatically improved - never used a 3 vessel system, just went to Brewzilla from BIAB in a basic electric Tea urn (now my HLT).

I will try using a slightly bigger crush setting for the next one. Interested in how you are treating your grains - What kind of treatment are you talking about?
 
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Hop_it

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Thanks for all the info!

I tried it this weekend at 1.14 from the first suggestion and got a stuck mash even with 100g of rice hulls - unfortunately lost efficiency (aiming for 6.9% and got 6.3%) - although it was a big grain bill and had to remove some of the water once I put the grains in - I think I just tried to brew too much for the kit!

Lesson learnt from this weekend - don't try and do too many new things at once (Big Grain bill, New Brew Space, Milling own grain) so you can't diagnose which gave you issues.

On the convo of Brewzilla/AI1's and 3VS's, I've done maybe 10 or so brews now on my Brewzilla and really think its brilliant - definitely made brewing simpler and less mess, and beers have dramatically improved - never used a 3 vessel system, just went to Brewzilla from BIAB in a basic electric Tea urn (now my HLT).

I will try using a slightly bigger crush setting for the next one. Interested in how you are treating your grains - What kind of treatment are you talking about?
I'm not sure if your question was addressed to me or not, but I assume you are referring to "conditioning" . . . . . This is a process to dampen the whole grain before milling. It slightly softens the husks so they don't crumble and break up too much. This improves their ability to act as a coarse filter (in a similar way to what the rice hulls do - or are at least meant to do). You can find various info on the internet but this article explains it quite well:
 

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