[flbrewer]

I noticed today after cleaning out my mash tun that I had some shiny metal bits below the bottom of the screen. This has happened before (previously with the Barley Crusher, now while using the Monster Mill) and I didn't see anything make it to the final product.

Has anyone ever seen any metal at this point in the process? I can only assume it's from the mill. The volume of shavings is minor and the particles are extremely small. Thoughts?

*FWIW, last time this happened I went so far as to put rare earth magnets on the plastic fermenter and nothing stuck to it.

[a10t2]

If it's persisted across two mills I'd be more inclined to think it's coming in with the malt, or from the mash tun itself. Either way I wouldn't worry about it if it doesn't make it to the package.

FWIW, 300-series stainless steels are non-ferritic and won't adhere to a magnet.

[reverseapachemaster]

Is it possible the screen is discharging small pieces of metal?

[gymrat]

Is it possible the screen is discharging small pieces of metal?

I think this is far more likely than the mill. Especially when it has persisted after a second mill. I would be very concerned it doesn't take much of that making it into the final product to become a serious health issue.

[flbrewer]

Mystery over, after a close look at the rollers I saw the tiny flakes of steel that were coming off (pictures below). When I placed some rare earth magnets over various parts of the rollers, I could see the flakes raise off the rollers. I am really surprised at how much is coming off the rollers. The more I run the magnets over it, the more comes off. I can't imagine any amount of grain would be able to take these shavings off. The fact that this has happened to me with two different mills (assuming two different manufacturers) leads me to believe it's a widespread issue. Perhaps people just aren't catching this or aren't looking?

I'm going to hit it with a wire brush and see if I can't fix this!
http://imgur.com/pAp5x2y

http://imgur.com/LOcTHyX

[mchrispen]

That is crazy! Looks like the knurling wasn't properly completed and cleaned up. I would show those pics to Monster!

[Philbrew]

That is crazy! Looks like the knurling wasn't properly completed and cleaned up. I would show those pics to Monster!

+1  It almost looks like plating coming off but that doesn't make sense if it's magnetic.

[Philbrew]

... leads me to believe it's a widespread issue. Perhaps people just aren't catching this or aren't looking?

I just got a new Cereal Killer mill that I haven't tried yet.  You bet I'm gonna grind a lb. or two and check it real close after seeing that.

[flbrewer]

Someone elsewhere suggested running rice through it on a tight setting. Apparently it's a great cleaner for new mills

[Philbrew]

Someone elsewhere suggested running rice through it on a tight setting. Apparently it's a great cleaner for new mills

Thanks, I'll try that.

[narvin]

It seems very odd that two different mills would have this problem without any other factors involved.  Are there rocks in your malt?

[flbrewer]

It seems very odd that two different mills would have this problem without any other factors involved.  Are there rocks in your malt?

I don't think it's odd. I think it's more prevalent than you think. No rocks as far as I know. I buy all my bulk malt from Rahr in 55# sacks. 

[JT]

Did you alter the gap at all?

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[narvin]

It seems very odd that two different mills would have this problem without any other factors involved.  Are there rocks in your malt?

I don't think it's odd. I think it's more prevalent than you think. No rocks as far as I know. I buy all my bulk malt from Rahr in 55# sacks.

You saw it at the bottom of your mashtun.  Why haven't other people?  Seems like it would be obvious. I doubt you're actually more observant than other homebrewers who can be... a bit obsessive 

[Stevie]

I've never noticed it, but I haven't looked either. I don't know how one could see the metal with all the grain bits.