Milling where you're brewing. A no-no, yes?

Hi,

I believe I've heard/read that one should avoid milling grains near the area where a mash/brew/boil will take place when milling the same day as brewing. Does it have to do with grain dust?

Anyone know why this is, exactly, and what the negatives would be if one did this?

Big thanks,
Nige

Only if you get grain dust in your fermenter, it's full of wild yeast.
I brewed and milled grains in the same room for 3 years with no infections. I also store grain and kegged beer in the same freezer. Common sense and good sanitation will help.


_

I really don't think this is an issue for your average homebrewer making 5 or 10 gallon batches, one batch at a time.

Large breweries have to be careful because of the massive amounts of grain leading to massive amounts of dust floating around. That dust can (a) combust of fire gets to it or (b) carry lacto and other buggers into fermenters (grain is laden with crud like that). They are always brewing and milling and transferring something all the time, so they have to worry about this stuff.

If you're grinding up 8 to 30 lbs of grain at the start of your day, and then brewing a single batch, you don't have to be concerned. That dust is small and will basically be gone from the air before you even sanitize your fermenter.

Never heard that one before... It might depend on the type of mill you're using. If you're using a corona style, which can toss grain (and parts) all over the place, it might be not such a good idea. But, if you're catching the grain into a bucket, using a hopper to feed it, I don't see any reason to not do it where you want. I'm talking about pretty much any mill that uses rollers to crush the grain.

I'm brewing tonight, and will be milling my grain less than 10 feet from where the kettle will be setup (more like 5-6')... It probably won't be cooking at the time, but it will be getting ready.

I probably wouldn't mill my grain near an open flame, but if you're at least semi-smart about it, you shouldn't have any issue. If you see a layer of dust after you milled, make sure your mill fits the bucket top properly, and clean it up before starting the fire to heat your water... Use some common sense here Hoss...

I agree while there is possibly some concern over wild yeasts and whatnot, it is more about fire hazard. It's just common sense that you don't want a bunch of fine particulates around an open flame.


Also Wildwest I like your updated pic!

Thanks, gents. I do use a Corona mill and catch the grains with a large Tupperware container, emptying the crushed grains into a bucket (that I re-cover with a lid placed on top) as the container fills. That said, my fermenter's still in a closet down the hall when I'm crushing, and my kettle's not too far away but is lidded during crush time.

My MLT (cooler) is preheating while I'm crushing, and it's (obviously) sealed shut. Sounds like I'm pretty safe?

Cheers.

Not to do with the brewing.

It is to do with the fermenting.

You can mill where you brew and be fine but if you ferment in the same space, consider the front porch.

nigel31, with all that you're doing, I would just make sure there's no open flame close to where you're milling. You should be fine with that caveat...

I will say that having a mill that goes directly into the bucket is really nice... Less dust gets into the air, plus more of what you mill gets into the batch. You're probably not losing all that much with how you're doing it. For me, that would get pretty old, really fast.

The biggest worry about this has been Lactobasillus on the surface of the grain getting kicked up during. But like a lot of folks have said they haven't had issues on the homebrewing scale. Other's try to avoid it as much as possible.

The thing to think about is that- It's going to be several hours between milling and having cold wort waiting to have yeast added to it and therefore vulnerable. And you're usually brewing outside.

Chances are, even indoors the "dust" would have settled in those 4-6 hours of brewing.

If you're a stove top brewer you probably don't want to mill your grain in your small enclosed kitchen or wherever you pitch yeast but if you do it even in another room (if I'm doing it inside I'm usually milling on my dining room table which is another room) it's probably not going to be that worrisome, especially if you have a window open, run a fan or even have traffic shifting the air current about. But it's just as risky to brew ANYWHERE if you want to worry about airborn issues. You can't really escape from them, unless you brew in a cleanroom. The kitchen in my lost is a tiny galley, so I wouldn't do it...plus it would already cramp things further.

That's why we pitch yeast a fast as we can, or cover the wort if we can, or at least get it sealed like no-chilled brewers do asap,

Ahh, so it has to do with the fermenter. In that case, I'm totally okay.

I'd love to have a Barley Crusher or a similar mill that fits over a bucket. When I got the Corona (a desired/asked-for gift at the time), I was only doing steeping grains and hadn't planned on going all-grain at the time (WHY don't any of the bibles of brewing ever suggest 2.5- or 3-gallon batches?!?), so for what I was cracking, it was fine. Didn't see the need to spend $125 when I could only spend $25. I'm happy with my Corona, but would be happier with a BC, but hey, it works and I do keep dust down when I mill, so for now, I'll be just fine, methinks. Since I'm not doing 5- or 10-gallon batches, my grain bills are under 12 pounds, so the Corona, while being slower and more fiddly, does the job nicely. Since I'm no-sparging it, the crush needn't be picture perfect, either, though I do pay constant attention to the crush as I do it.

And no, there's no flame on nearby when I'm crushing. Thanks, though.

i imagine if you condition the malt before milling it would reduce this possible problem?

nigel31 said:

Ahh, so it has to do with the fermenter. In that case, I'm totally okay.

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Infections and sanitgization always are a POST BOIL issue...it's not anything getting in or touching anything before or during the boil...everything's killed in the boil.

It's once the wort has dropped below pasteruization temp that you have to be careful, and pitch as soon as you can, or seal the fermenter. You really want to get your yeast in there so it can take hold before any wild buggies do. Wild bugs like lactobasillus for instance.

As soon as I'm done aerating (after chilling and then siphoning the wort into the carboy), I pitch my yeast and seal it up, all sanitized and whatnot. Guess I'll be safe enough, then.

And for the record, I do brew totally indoors. I haven't an outdoor space where I can mill or use a propane burner, but I'm happy doing what I'm doing and with smaller batches.

Thanks to all for chiming in.
Nige

Come on guys, don't smoke when you crush, you'll blow up. You'll infect your beer. Come on, guys. Crush at the neighbors house. You don't want infection. And put lotion on your arms. But use the back of your hand. And wear gloves in case you get dust on your hands, you can take off your gloves. That's how we do!

Revvy said:

Infections and sanitgization always are a POST BOIL issue...it's not anything getting in or touching anything before or during the boil...everything's killed in the boil.

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Not true. People who do extremely long mashes or mash the day before brewing can get lacto sourness in their wort. boiling kills the bug, but not the flavor it has already produced.

Grimm said:

i imagine if you condition the malt before milling it would reduce this possible problem?

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It does a little bit but not that much, you're not adding very much water and most of the endosperm are still about as dry as before conditioning.

TBH, I don't see much dust when I mill my grain (I do condition it)...but I see I huge amount of it as I dump the milled grain into the preheated mash tun. And we generally do that where we brew (i.e. more specifically, that's where we chill the wort after the boil). IMO, if grain dust is a concern then that is a bigger issue than where you mill it. I actually wipe down the brew stand and remove/clean the mash tun before the end of the boil just because I can see all that dust on everything.

SpanishCastleAle said:

but I see I huge amount of it as I dump the milled grain into the preheated mash tun. And we generally do that where we brew. IMO, if grain dust is a concern then that is a much bigger issue than when you mill it. I actually wipe down the brew stand and remove/clean the mash tun before the end of the boil just because I can see all that dust on everything.

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This is a good point. And I do that IN my enclosed kitchen when I brew indoors. And there hasn't been any problems in all these years. But I think I need to be more aware.

It takes a significant amount of dust to be combustible, but I won't hazard a guess as to whether grinding a 20lb grain bill would be enough.

Fun reading about mill explosions though:

The first Washburn A Mill, built by C. C. Washburn in 1874, was declared the largest flour mill in the world upon its completion, and contributed to the development of Minneapolis. On May 2, 1878, a spark ignited airborne flour dust within the mill, creating an explosion that demolished the Washburn A and killed 14 workers instantly. The ensuing fire resulted in the deaths of four more people, destroyed five other mills, and reduced Minneapolis’s milling capacity by one third. Known as the Great Mill Disaster, the explosion made national news and served as a focal point that led to reforms in the milling industry. In order to prevent the buildup of combustible flour dust, ventilation systems and other precautionary devices were installed in mills throughout the country.

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Sick stuff, Mischief. Very interesting, though. Crazy to think that something airborne would just catch and blow the place to hell. Hmmmm.

I agree there would need to be a lot more dust in the air than what you would ever create by grinding 30 lbs of grain. Working in the grain industry have been lectured several times about this, but to be truely dangerous, you would have a hard time breathing because of the dust, and I have never seen anything close to that while grinding. Also, it has to be in a concentration in a confined space, just having a dusty area in a large room wouldn't be too much problem.

BUT I am not saying to test out what will cause the explosions!!!

Just googled this:
Four ingredients are required for a grain dust explosion:
Ÿ oxygen,
Ÿ ignition source,
Ÿ fuel, and
Ÿ containment.
All four ingredients must be present for an explosion to occur. An explosion can be prevented by
eliminating any one of the four ingredients. An oxygen-free environment in grain elevators is
obviously impractical. OSHA and the FDA have established numerous regulations and guidelines
to eliminate the ignition sources. The fuel for a dust explosion is the grain dust in suspension in
the air at or above the minimum explosive concentration (MEC). Most experts use 50 grams per
cubic meter (g/m3) as the MEC for grain dust. If the dust concentration at a grain transfer point is
less than the MEC an explosion will not occur even if all other ingredients are present. A
concentration of 50 g/m3 is so high that a person standing in this concentration would not be able
to see their fingers one foot away. The engineering strategies for reducing the probability of dust
explosions include pneumatic dust control, liquid additives, enclosed conveyers, direct spouting
and other equipment and techniques that reduce and/or eliminate dust emissions. These strategies
are directed at reducing the concentration of grain dust suspended in air at grain transfer points
and thereby eliminating one of the required ingredients for an explosion -- fuel

We used to play with non-dairy creamer packets and matches. Pour too slowly and you don't get a flare up, pour too fast and it puts out the match, but pour just right and you can have a huge flame burn its way up to your hand. It smelled kinda good too, although I like me some burnt sugar smells...

I'm opening a bakery where we'll be milling whole wheat flour every day on a 20" stone New River Mill. Unfortunately for my wallet, but fortunately for safety my city is requiring all this venting, explosion proof lighting, hard-wired everything, electrical switches outside, and 90minute walls... damn my budget, but you can't fight city hall.