Grain Crush

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Hi siiren and others,
There are pics in the gallery of my modified Marga Molino and later today I will post the roller gap settings that I have mine set to.
With the Marga it is important that the gap on the top two rollers is wider than the gap between the bottom or outlet.
The pic above of the crush looks pretty good to me and I judge my crush results by grabbing a handfull of grain and picking out one grain that looks to be intact and touching it and the husk should readily fall open to reveal the white malt inside. With most grains the husk is broken to reveal the malt.
Crush plays a big part in mash efficiency and if you are consistently getting 70% plus then your crush should be OK.
Here is a pic of me drilling the index plate on my mill.

Sorry no pic now original pic was too big. I will try to get it smaller and repost it.

Cheers
 
Thanks Dicko,
Exactly what I needed to know.
What time frame are you looking at for a 6kg crush with the mods?
Cheers.
 
Siiren,
My mill rollers are set to .086"inches clearance for the top and .070" inches clearance for the bottom.
Apart from drilling the index plate there is a slight adjustment available by turning the hexagon part of the bushes that the rollers run in to achieve a very fine adjustment. These bushes are slightly offset to allow adjustment to maintain a parallel relationship of the rollers.
I most cases you should not need to mess with these.
I have now chosen to do away with that silly plastic hopper altogether and I have made a hopper that fits into the top housing with an interference fit and makes use of the full length of the rollers. I made it from MDF board and it holds 4.5 kg of grain at one time. (see the gallery pics )
The drive pin that Grumpys gave me broke when I put too much pressure on it with the drill so now I have cut the tip end of the shank of a large flat screwdriver and ground the sides to fit the slot in the drive shaft and it works a treat.
Dont take my clearance as absolute, but slowly adjust you rollers to achieve the crush you want. My settings will get you very close to the mark.
A hint is to use some tape to hold the adjustment knob until you get it right then mark it and drill one hole instead of a series of holes like I did.
If you need any help then PM me and we can get in contact by phone if you wish.

Cheers
 
Siiren,

Our posts overlapped each other.
With the big hopper and using the drill to drive it, it takes only a few minutes to crack five kilos of grain. I would say at a guess less than five minutes.

Cheers
 
/// due to a mistake in signing up.

Sweeping statements - well why not - tis' the season too!

Credentials - less than some and more than others on the board.

Flaoting mashes I have found to make a huge difference and have a couple of times in a brew house the problems with a set mash.

Aeration is from doughing in - many systems that use a auger have a chinese hat for the malt to go thru. At home I make sure that there is a good grain to water ratio and during sparge out keep the outflow and inflow to the mash tun about the same
 
pint of lager said:
The ultimate crush would be the husks intact (these are what filter the sparge, not the false bottom or manifold) and the starch to be broken into 1/2 a dozen pieces with minimal flour.

If the husks are really ground up, like wholemeal flour, it would be impossible to sparge, the whole lot would set. Also, there would be excessive tannins leached from the extra surface area of the husks.
I end up with my husks intact but squished flat. The white stuff comes out quite powdery.

BarleyGrind.jpg


I so far haven't had a stuck mash and people keep telling me there is very little risk of tannin extraction with batch sparging. I have had no evidence of astringency.

Having said that, I brewed a pils the other day and Melbourne water is very soft so I tossed a few drops of phos acid into the sparge water to keep the pH well under 6.

rollero-ring.jpg


A close up of part of the rollers.

The full details are here
 
Hi Sosman,

Looks pretty good with that crush.
Your mill is quite impressive and I would imagine that by the size of the rollers it would be quick as well!
I have mucked around with my Marga and got it working pretty well and I can achieve 75% easily from my mash with a simple batch sparge and 72% with the "no sparge" method.
The pic of the grain shows that you are cracking the husk but leaving it in tack so that sparging should be a breeze.
I use a false bottom in a stainless vessel as a tun and I think from memory that you use a manifold or bazooka in an esky?
What sort of efficiency are you getting with your system?

Cheers,
 
Dicko,

I have been hitting 90% regularly batch sparging, with one dropping to 83% - what the cause was I don't know.

I use the braid off an easy hooker. Pics of mashtun and batch sparge method I use are at

brewiki: batch sparge

I can hand crank 5.5kg in around 4 minutes. It is improving with age (well and the fact that I added an o-ring to both ends so the second roller has a good positive drive).
 
Sosman

I have found that if I use wheat malt in a recipe that my efficiency drops by about two points generally and I believe that this drop is directly related to the fact that the wheat grain is slightly smaller and that I dont get the crush with the Marga unless I select the closer setting on the rollers.
Personally I could not be bothered to crush the wheat seperately so I just accept the result as long as I know what is happening and why.
The "o"rings on your rollers would compensate for the fact that steel rollers are knurled and if both rollers are turning then this would help "pull" the grain through the rollers.
After many trial runs and resetting adjustments with the Marga Molino I now realise how important the crush is in achieving mash efficiency and this fact should not be underestimated with any brewer contemplating AG brewing.
Your mill is a credit to you and it obviously is doing exactly what it should.

Cheers,
 
A reasonable pic? My camera doesnt go that close. But I did some trial milling with my Valley last weekend and got the best pics I could.

The valley has about 6 or 7 fixed gaps.

Coarsest setting, lots of uncracked grains.

valley_coarse.jpg
 
Once you close the gap to some critical point related to the size of teh grain, it starts to crush properly, and you dont see a big difference by changing the gap.

This is 3rd finest setting which I mostly use.

valley_third.jpg
 
Finest setting. Doesnt seem to be a big change (from third setting) in what happens to the husks, just a bit more powdery stuff from the endosperm(insides? sorry wes). Actually looking at this there is still enough husk to filter, might go finer next brew.

valley_fine.jpg
 
top pics gl.
im going to do a schwarzbier tomorrow so if i remember i will take and post some pics of a barley crusher crush set on about a gap of .038 thou from memory.

cheers
big d
 
I'd be really interested if someone could add some pics of a marga or porket crush as well, would be a useful resource.
 
I'm after a few opinions on my own crush. These pics are after 2 runs at .65" gap (measured with spark plug feeler gauges). There are a fair few grains that appear whole, but a very gentle rub between two fingers has them falling apart. Under the top layers there is a fair bit of flour.

Prior to this run, I normally did a crush at .85" and then again at .65" but didn't get very good efficiency so tried this as something different. I'll be brewing with it tonight.

Thanks for any advice

Final_Crush_A.JPG

Final_Crush_B.JPG
 
Boots said:
I'm after a few opinions on my own crush. These pics are after 2 runs at .65" gap (measured with spark plug feeler gauges). There are a fair few grains that appear whole, but a very gentle rub between two fingers has them falling apart. Under the top layers there is a fair bit of flour.
[post="53852"][/post]​

Boots

What sort of mill is it? I think the crush could be a bit finer so more of the grains are broken up.

Cheers
Pedro
 
GulfBrewery said:
Boots

What sort of mill is it? I think the crush could be a bit finer so more of the grains are broken up.

Cheers
Pedro
[post="53855"][/post]​

Meant to say that it is a Marga Mill. I might do it like it is for tonights brew, and then next crush go down to .60" or less to see the difference in efficiency.

Cheers GulfBrewery
 
i agree with pedro
my bc is set at 35-40 thou.cant remember which on but the results are good.


cheers
big d
 
The crush looks good Boots.

Dicko, could you please delete your picture, resize and repost.

Gap size may need to be changed depending on what sort of grain you are crushing. Malted oats needs a much smaller gap.

Depending on what variety of barley the maltster has used, means that once again you may need to adjust the gap. Also, if the barley is poor quality, there will be a big distribution of grain size, some small, some large and the gap size will not be right, no matter what you set it at. There will always be a few smaller grains that get through, do not worry if you have some that gets through. After mashing and sparging has finished, is the easiest time to check for uncracked grain. Pick out a handful of spent mash, and inspect for whole grains.

The ideal would be to run the grain through twice, first on a wide setting so the barley is just cracked, the second, on a much narrower setting so the starch bits get crushed finer. This is why some people opt for a 3 roller mill, like the crankandstein.
 

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