Recommended Mill Setting

[QldKev]

Sorry about the site, it's currently a hack site for scripting and php work.

I will clean it up one day.

QldKev

 

[Tony]

Crushing is a very complex question; I don't want anyone to think of this as an add, but I get through a lot of malt every month and it's a bigger range of malts than any home brewer could possibly use. As a retailer we have to crush for dozens of brewers using different systems who all have their own thoughts on how they want their malt crushed.

I'm lucky to have a really good mill; it has large 175 mm powered rolls, flutes rather than knurling and very importantly for me it's really quick to adjust. Shawn at Murrays has the same type of mill and he has his locked at 1.5 mm, but like most commercial brewers he is mainly crushing one type of malt. At a Craft/Retail level its different, we are never crushing anything like the same malt bill twice (that's why a quick adjuster is necessary). I find as a general rule UK malts are shorter and fatter, German/Belgian next fattest and Australian malt to be the longest and thinnest.
We always run grain through the mill at least twice; if there is a lot of wheat (over 10%) it gets crushed first, then mixed with the barley and remilled, I find wheat if crushed to its final size (~0.5 mm) in one pass generates a lot of flour but if you sneak up on it a bit you can get a very fine kibble and very little flour.

As an example of what I'm talking about the last beer I brewed was a Belgian Wheat, Made up of: -
Dingemans Pilsner 58% Crushed to 1 mm
Wheat (Un-Malted Australian) 34% crushed to 0.5 mm
Malted Oats (UK) Crushed to 0.1 mm
The three malts were obviously crushed separately then mixed by running through the mill, this is them before mixing. I got 83% brewhouse yield so what I did worked.

It's far from just being a question of "Mill Gap", the size of the rollers, the surface, whether they are powered or one or more are idling, the surface speed, the material being crushed, and the speed of flow of the malt into the rollers are all probably just as important as the gap. The moisture content of the grain, the equipment the grist is going to be used on are also very important.
For me the biggest single factor is how fast you lauter, if you go slow enough very coarse crush (search Floating Mash) can give the same yield as a fine one, and who can forget TB's experiment where he got 45% extraction from uncracked malt (surprised the hell out of me).

So your system, how you use it, what you are crushing are all just a part of the picture.

Mark... you and i have had our differences but i have to give credit where its due.

Top post!

I keep several base malt bags here at any one time, and find i get very different results with the different varieties. I was going to mention the differences between pommy, german and aussie malts but MHB covered it all. I have my mill (10" long rollers 4" Dia turning at 160 RPM) set at 0.9mm. I generally get a finer crush with this, containing a fair amount of flour but it works in my system.

I have been toying with the idea of opening up the mill a bit and trying 2 runs to get a fine grist with less flour. Wheat malt and weyermann Pilsner give me a lot of flour with one fun through a small gap.

Might have a play with the Kolsch im making on the weekend.

Cheers

 

[SpillsMostOfIt]

<Snip>
I have my mill (10" long rollers 4" Dia turning at 160 RPM) set at 0.9mm. I generally get a finer crush with this, containing a fair amount of flour but it works in my system.
<Snip>

This is really illustrative. In a good way...

The linear speed of your mill is 4 * pi * 160 inches per minute. To get the same linear speed out of, say, a MM-2 or a Crank 2S, you would need to turn the rollers at 160 * 4/1.5 RPM which is lots higher than people often recommend.

The real takeaway message from this and MHB's comments (in particular) is that you should rely on your own experimentation more than on what other people are doing.

 

[Fourstar]

Fourstar - when you do your next batch could you take some close ups of the milled grain?

Will do mate!

 

[Fourstar]

Fourstar - when you do your next batch could you take some close ups of the milled grain?

for reference:
80% pils (JW)
10% Carapils (weyermann)
10% Muncih (weyermann)

Same gap setting as noted before. used drill by pulsing and never letting it go full-tilt.

Notice the grain kernels have been 'broken' but not smashed to ****. some may say this is too coarse but when you finish your sparge and there is no clag glue trap on the top of the grainbed, i think its just right. (especially when you see no significant difference in efficiency.) any kernels you see there that look intact, a little squeeze and they are broken the same as the rest of them.

The real test i see is when you rub it between your hands. if you notice no extra flour but a good even particle size, your onto a winner. :icon_cheers:

I think with using a drill, there is a fine line between the rpm and gap setting.

cheers.

 

[cdbrown]

Thanks for that mate. A courser crush just means a longer mash time, but a quicker sparge, so I think you've probably got it right. My last mill there was quite a lot of flour in the bucket and I think it's all down to the speed of the drill. Might try opening it up another notch and running a small amount through to see how that goes.

 

[Fourstar]

Thanks for that mate. A courser crush just means a longer mash time, but a quicker sparge, so I think you've probably got it right. My last mill there was quite a lot of flour in the bucket and I think it's all down to the speed of the drill. Might try opening it up another notch and running a small amount through to see how that goes.

not even that, my efficiency has not changed (it typically waves around 68-72~% depending on grist, adjunct and expected gravity. ) i stay the pessimist and build all of my recipies for 68% so if i overshoot, i can always water it down a notch before flameout,

but yes, im a big fan of this crush. infact looking at it now on a big screen (last looked on my iphone and netbook) it looks coarser than it does to the naked eye. either way, im a big fan so far and the less husk shred and flour the happier i am! :icon_cheers:

 

[gilmoreous]

Has anyone changed/updated their practices in the last few years?

 

[HBHB]

Has anyone changed/updated their practices in the last few years?

Not likely. Barley is still barley, rye is still rye and wheat is still wheat. If you're doing a mixed bag of grains, separate them and mill according to what you see. Mill twice to bust those smaller grains like wheat, rye and naked oats. Etc.

Check MHB's original answer for best practice. After good recipes, Good beers start with good milling.

 

[Batz]

I have been milling my grain on the same setting, on the same mill for over 14 years. First the 3v then the BM, I have never found a need to change it, I do crush on the finer side.
Mill what works for you, what more could a brewer ask for?

Batz

 

[Spiesy]

Repeatability and an enjoyable brew day is more important that a crazy high efficiency, in my humblest of opinions.

 

[Batz]

Repeatability and an enjoyable brew day is more important that a crazy high efficiency, in my humblest of opinions.

Agreed, and both are easily achieved. :beer:

 

[seamad]

I don't adjust my mill either, mainly because it gives me the absolute ***** to do so. It's a ss monster 2 and I find I can adjust it and tighten the locking screws only to find free wheeling the roller changes the setting by @ .15mm. It has done it since new and wonder if this is common with this type of roller adjustment.
Using a RIMS system I'd rather a lower efficiency over a stuck sparge anyday. I've found the biggest improvement in grain crush has been adding 20ml water/kg grain and mixing up and leaving it for 1/2 hour or so prior to milling ( twice usually @ 1.1mm +/- roller creep ) . The white plastic 20l buckets with lid are good for this.

 

[Yob]

Seamad, is that to keep the freewheel roller engaged? I've a mm3 and have only used it the once thus far, but I was thinking of attaching an Allen key to the end of the roller so if it spins, I can easily back spin it.. I've not got the ss rollers so don't want to go down the damp route.. Watcha fink?

To stay on topic, I'll add I use a credit card (swmbo's) to set it

 

[Screwtop]

I have been milling my grain on the same setting, on the same mill for over 14 years. First the 3v then the BM, I have never found a need to change it, I do crush on the finer side.
Mill what works for you, what more could a brewer ask for?

Batz

Same here for 9 years set at 40 thou (0.04 inches) or 1.016mm

Honestly there's way,way more important brewing **** than mill gap...................


Screwy

 

[Ducatiboy stu]

Mine is 0.9mm. I use a piece of 0.9mm copper wire to check it, same rollers as Tony.

There really is no one-size-fits-all mill gap.

You just have to play with it until you get it, but its not worth fussing over.

 

[TidalPete]

Same here for 9 years set at 40 thou (0.04 inches) or 1.016mm

Honestly there's way,way more important brewing **** than mill gap...................


Screwy

They must be having a gap year Screwy?

10 years at 40 thou here.
When I first got the 3-roller Cranker I adjusted once for wheat before realising there was no need.
Harder grains like Rye, Terrified Wheat, etc are best run through the mill twice. Once on their own then again with the rest of the grain bill.

 

[seamad]

Seamad, is that to keep the freewheel roller engaged? I've a mm3 and have only used it the once thus far, but I was thinking of attaching an Allen key to the end of the roller so if it spins, I can easily back spin it.. I've not got the ss rollers so don't want to go down the damp route.. Watcha fink?

To stay on topic, I'll add I use a credit card (swmbo's) to set it

No problems keeping the free wheeler engaged, never had slippage yet ( bet ol murph is having a chuckle). It's just I find after I remove the feeler gauge that the gap changes after freewheeling the roller. With the mm3 probably no need to dampen the grain as less likely to get husk damage with the 3 roller anyway.
cheers

 

[black_labb]

I use a pretty coarse crush as I recirculate from the top down. If the mash becomes stuck and I don't catch it in time it overflows. I've been meaning to install a float switch in there but I haven't gotten around to it as I've become pretty good at getting a good grain bed. Either underlet or add the grain to the water letting it float down on it's own time makes a huge difference in my experience.

You might get a bit more extraction with a finer crush but you lose that efficiency gain with a dough ball or 2. You lose it even quicker if you overflow wort onto the floor.

 

[Eagleburger]

mashmaster mill, 1.4mm gap, recirc. top down, no sparge, 6:1 grist, 77% according to brewmate.

At that setting there is virtually no flour and half the grain just has a single crack in the middle. If I squash the spent grain in iodine there is still starch left. should I worry?

Mash longer, crack finer?