Grain - Minimum size?

[MaximumTrainer]

I was wondering if there is a minimum size for the grain crush?

Let say I crush it really small, some grain (flour) will end up in the fermentor.
At worst, this grain should settle at the bottom of the carboy during fermentation?
Is there a point where too small of a crush can cause problem?

Any suggestion appreciated, just bottled my first brew.
It was a bit cloudy so i'm wondering if the crush could be of problem.
Crush was made with a Barley Crushed set a little bit smaller than a credit card

 

[pricelessbrewing]

Cloudy beer could have a couple sources. I'll address them in chronological order.

Grain making it's way into the brew kettle. Too much, and too low/high of a PH and you can extract tannins as well. I've never had any issue with this because I use a proper swiss voile biab bag from @Wilserbrewer

Hot break / cold break. This is proteins that come out of the wort as it's boiled/chilled. To aid with this you can 1) Add irish moss/whirlfloc which acts as a coagulant and causes it to clump and fall out of suspension. 2) Whirlpool (aka stir) your wort as it's chilling. Let it sit for 10~ minutes to form a nice layer in the center of the brew kettle, then rack to your fermentation vessel. I don't really do this as it's an extra step attempting to solve a problem I've never had. Note: there's two camps on this one, camp 1 wants the clearest wort possible because they think it makes their beer better/clearer. Camp 2 doesn't care, and their mindset is that crystal clear wort actually inhibits fermentation as the break material is a source of yeast nutrients. Also cold crashing will drop all of this out of suspension, and is best practice if you're worried about clear beer.

Yeast, trub, and hop particles. These are all created during fermentation and dry hopping. All of this can be helped by longer primary/secondary, cold crashing, and using a fermentation fining agent like gelatin of fermclear. Also bad racking practices can disturb the trub at the bottom and cause some to kick back up into suspension.

 

[RM-MN]

I think I have a finer milling than your barley crusher can make as I set my Corona style mill as tight as I can and my beers still come out clear.

 

[theseeker4]

I was wondering if there is a minimum size for the grain crush?

Let say I crush it really small, some grain (flour) will end up in the fermentor.
At worst, this grain should settle at the bottom of the carboy during fermentation?
Is there a point where too small of a crush can cause problem?

Any suggestion appreciated, just bottled my first brew.
It was a bit cloudy so i'm wondering if the crush could be of problem.
Crush was made with a Barley Crushed set a little bit smaller than a credit card

The biggest problem a too fine crush can cause is stuck sparges with traditional 3 vessel brewing. If you use BIAB, that is not an issue. As you said, if you get a lot of grain in the fermentor, it will settle out with the trub, and shouldn't contribute to hazy beer. Hazy beer is usually due to proteins that are dissolved in the beer when it is warm, but come out of solution at colder temperatures, forming "chill haze." That can be cleared to some extent with finings like Irish Moss, cold crashing, and gelatin.

 

[MaximumTrainer]

Thanks guys! Confirming was I thought, I will keep my grain crush as it is.