Mill Gap Setting

[Bainbridge]

Addendum: Van gave the talk again at the CBC I guess, and the last MBAA District NW meeting (I know 'cause I watched that one) so you can look for the pdfs around. Or here, for as long as it holds.

[Bainbridge]

Well the point is there's the scientificated ASBC way, and there's this way, the quick and dirty way. But a 70/30ish split on a #14 shaker tray is more or less where you want to be. Also the second link is down it seems. Lamers.

We just checked our mill this morning actually. Amazing what a small adjustment on a mill not specifically designed for malted barley will do. A millimeter here and there was: 64/36, 67/33, 75/25.

[dhdarden]

Do you have to join the ASBC to get its procedure for measuring Grist ?

I'm hoping this procedure (using the sieves) is available without having to join the ASBC. Is there a link to the measurement procedure somehwre ?

Thanks,

Dan Darden
Darden Consulting LLC

It's tough to use feeler gauges, since there is play in the bearings. One way to check is to run a soft piece of metal, like solder, through the mill and measure its thickness with calipers.

But the best way is to buy or borrow a set of sieves.

[TGTimm]

Thanks, Russell--that one works. Now to do some reading....

[Bainbridge]

Yeah looks like the link went down. Here's another version: https://www.yumpu.com/en/document/vi...craft-brewers-

[TGTimm]

UPDATE: So we adjusted the mill to a couple different settings that looked in the range, then compared the grind side by side using both Gambrinus ESB and GW Pale Ale malt. Found one that looked best overall on visual inspection and used it. Got 85% efficiency on a 1.078 (19 plato) wort. The sifting screen showed up the next day and I ran that grist through using the Van Havig method from his Rock Bottom days (you can find a pdf of it here: http://tinyurl.com/andldef ). Rather than buy all the different screens we just used the #14 screen, then shook 3 minutes, weighed what went through and what stayed, looking for 70% on top, 30% on bottom. We got 67/33, which is ok by me. It was the finer grained GW Pale Ale, I expect it'll be 70-ish with the plumper (and moister) Gambrinus. (Seemed like those husks held together much better.) Brewday tomorrow, we'll see what we get.

Your link doesn't work. Could you try to re-post it? I'm very interested in this as we haven't checked our mill in quite a while. In the past, we've sent grist samples off to Great Western and had them analyze them, but I'd rather do it in-house.

And thanks for the solder-trick tip! I've been using feeler gauges, and sure enough, they don't work very well.

[MikeS]

Yeah it's interesting. Each kind of malt sounds different. I know when we're grinding light vs dark crystal, wheat vs barley, and when the grist case is full... All by the sound. Crystal in particular, much higher pitched, louder too.

Briess Carapils sounds like a hail storm on a tin roof!

[Hatchet Jack]

We lost efficiency for a while when a couple of bearings were going out. It wasn't obvious until we took it apart.


Aaron
Junkyard Brewing Co.
Moorhead M.N.

[Bainbridge]

Yeah it's interesting. Each kind of malt sounds different. I know when we're grinding light vs dark crystal, wheat vs barley, and when the grist case is full... All by the sound. Crystal in particular, much higher pitched, louder too.

[Brandjes]

I also use the single sieve. I got my rubber ball out of a .25 vending machine. Had a 70% efficiency day a couple weeks ago. The mill didn't sound quite right but I didnt think to check the grind. Lesson learned. The sound was a bit like running straight wheat through the mill. A lot of popping as the un cracked grain pops through


Sent from my iPad using Tapatalk

[Bainbridge]

Did you use a rubber ball in the sieve? If so, please tell me more about your ball.

Thanks,
Rich

Gather round children and I will tell you The Story Of My Ball!

So, lacking an Official Science Ball, I went to a local store and picked up a good sized marble.

[Rooh]

ball?

Did you use a rubber ball in the sieve? If so, please tell me more about your ball.

Thanks,
Rich

[Bainbridge]

@Sauce - That's a good point. The mill has a slide gate marked 'Zulauf' that can go all the way from hin to zu. I usually just set it so that it finishes the bag about the time I've got the next one open and ready. I do have to suspect that the cannon ball in our auger probably smashes things a bit on the way to the mash tun.

@juliobrewer - It's a German Engl Uni 40-18. Think it's a three horse as I remember. Two rollers. Finely adjustable, only there are no markings on the adjustment handle. You get the choice of "Spalt - <= GroB or Klein =>" So we just drew a line where we kinda like it and tweak it slightly from there.

Re: the solder strip. That's a pretty good idea!

UPDATE: So we adjusted the mill to a couple different settings that looked in the range, then compared the grind side by side using both Gambrinus ESB and GW Pale Ale malt. Found one that looked best overall on visual inspection and used it. Got 85% efficiency on a 1.078 (19 plato) wort. The sifting screen showed up the next day and I ran that grist through using the Van Havig method from his Rock Bottom days (you can find a pdf of it here: http://tinyurl.com/andldef ). Rather than buy all the different screens we just used the #14 screen, then shook 3 minutes, weighed what went through and what stayed, looking for 70% on top, 30% on bottom. We got 67/33, which is ok by me. It was the finer grained GW Pale Ale, I expect it'll be 70-ish with the plumper (and moister) Gambrinus. (Seemed like those husks held together much better.) Brewday tomorrow, we'll see what we get.

[Sauce]

Bainbridge,
Another thing to think about is mill load. We attempted to adjust our mill based on the "scoop full, inspect and adjust method". Found that the crush would become considerably finer when we actually milled a batch as the auger filled and/or the mill hopper filled.

As has been sad before, I think each mill is unique as far as what is the optimal gap setting.

Good luck

[BelgianBrews]

I set my gap at 1.7mm and get efficiency in the range of 90-92%. I'm also doing step mashes and single decoctions with German malt (Weyermann) which is pretty plump. If you are using domestic grain (especially 6-row) then you will need a tighter gap. When I go to 1.5mm or 1.6mm my efficiency does not improve, but I do have runoff problems. My advice is to set your gap as large as possible without sacrificing efficiency. A small adjustment can make a big difference.