Crushing grain for BIAB

[Morrey]

I just got my first 3 roller grain mill and looking into the grain grind for my BIAB brewing style. Since I won't have to worry about stuck sparges, can I grind more finely and be ok? I realize not to make a flour/powder grind, but can I be a bit more than lightly cracking the husk? By cracking a bit more aggressively for BIAB, will this show in my efficiency percentages? THANKS!

 

[cmb4642]

With a single crush on beer <1060 I get 60-65% and 70-75% with a double crush.

 

[Ameritoon]

I was told to get the best results from BIAB - crush it twice.

 

[brew_darrymore]

Yes, you absolutely can grind finer with BIAB. That's one of the advantages of BIAB. Your efficiency will improve for sure. I also do BIAB and get consistently 80-83% efficiency.

 

[TorMag]

Grind the crap out of it... The are numerous threads on here about the grind for BIAB. You want and need a finer grind.

 

[arnobg]

I crush with it set at .028 and get 79-81% every brew day. Don't need to double crush if you set it right first.

 

[Ike]

So, no concerns about finer crushes leading to (also finely crushed) husks finding their way through the bag and into the boil, causing astringency?

 

[TorMag]

If you bought a Wilsner bag, will be no problem

 

[petrolSpice]

With single crush I was getting 65-72% efficiency. The first time I double crushed I got 82%. I don't think it was any coincidence!

I've read about people blending their grains into powder, so don't worry yourself too much about crushing it too fine.

 

[doug293cz]

So, no concerns about finer crushes leading to (also finely crushed) husks finding their way through the bag and into the boil, causing astringency?

Astringency is caused by the pH being too high (over 6.) Keep your pH below 5.8 and you will not get astringency. If boiling alone could lead to astringency, then decocted beers would all be undrinkable.

Brew on

 

[doug293cz]

Double crushing is a band aid for those who can't adjust the mill they use to a fine enough crush. A correct mill setting is better than a double crush.

I set my two roll mill gap to 0.016" for BIAB.

Finer crushes give you faster conversion since gelatinization (the rate controlling step) proceeds from the surface of the grits towards the center. Smaller grits equals faster gelatinization equals faster conversion. Finer crushes can lead to better conversion efficiency (mash efficiency = conversion efficiency * lauter efficiency) when your mash time is not long enough to completely convert larger grits.

Brew on

 

[Morrey]

If you bought a Wilsner bag, will be no problem

Wilser bags all the way!

 

[arnobg]

As long as you use a high quality bag like Wilser bags you'll have clean wort. There is an experiment floating around somewhere comparing beer clarity between a BIAB and traditional mash/sparge. The results showed BIAB is just as clear if the rest of your process is sound.

 

[wilserbrewer]

I set my two roll mill gap to 0.016" for BIAB.



Brew on

Any trouble getting enough torque to the mill at such a tight setting?

I tried to run a tight gap on my Kegco 3 roller and I was afraid the drill was gonna rip the mill off the mounts, had to loosen it a bit lol?

As gap decreases, torque requirements skyrocket IME.

 

[wilserbrewer]

sorry double post

 

[doug293cz]

Any trouble getting enough torque to the mill at such a tight setting?

I tried to run a tight gap on my Kegco 3 roller and I was afraid the drill was gonna rip the mill off the mounts, had to loosen it a bit lol?

As gap decreases, torque requirements skyrocket IME.

No problem. I use a heavy duty HF battery powered drill. I've heard that three roll mills require more torque. My rollers are 5" long by 1-1/4" diameter vs. the Kegco's 6" by 1-1/2". The extra length and diameter both add more required torque.

Brew on

 

[MW66]

If you bought a Wilsner bag, will be no problem

Any comparison between the Brew Bag and the Wilsner? I like the heavy loops of the Brew Bag and haven't used a Wilsner. Is the mesh comparable? Just curious if anyone knows if there is a difference.

 

[TorMag]

Any comparison between the Brew Bag and the Wilsner? I like the heavy loops of the Brew Bag and haven't used a Wilsner. Is the mesh comparable? Just curious if anyone knows if there is a difference.

I've only used the Wilser Bag. It comes with a sturdy draw string with a plastic cinch. It is designed to fit tightly to the rim of your kettle and you strech it slightly over the rim. You also can suspend it by the cord for draining,but I don't do that, I built a PVC pipe rack that sits on top of my kettle and rest the bag on top of it for draining. I would assume the mesh is comparable.

 

[OkanaganMike]

I set my two roll mill gap to 0.016" for BIAB.

I don't have a way to measure the gap, I used a credit card as a tool as I've read that was the correct depth however I find it a bit too tight sometimes for my 2 roller set up and the grains don't engage. Rollers just spin and no grinding. Very frustrating when the hopper is full and can't get the grains between the rollers.

Edit - I use an electric 3/8 drill and works fine.

 

[kh54s10]

Agreed that you don't need to double crush. But if you don't readjust for the finer crush, you can double crush for approximately the same effect.

 

[MW66]

I don't have a way to measure the gap, I used a credit card as a tool as I've read that was the correct depth however I find it a bit too tight sometimes for my 2 roller set up and the grains don't engage. Rollers just spin and no grinding. Very frustrating when the hopper is full and can't get the grains between the rollers.

Edit - I use an electric 3/8 drill and works fine.

I believe a credit card is about 0.030". My current setup for AG is .037 for my 2 roller mill. I am just going into BIAB, so I plan to set my crush my lower, but not sure how low. Lately, I've been pre-wetting the grains and it has made a huge difference. However, does anyone do this for BIAB or is it a wasted step? I'm looking for anything that I can cut out. Right now, from start to the end of clean up, it takes me about 4.5 hours.

 

[doug293cz]

I don't have a way to measure the gap, I used a credit card as a tool as I've read that was the correct depth however I find it a bit too tight sometimes for my 2 roller set up and the grains don't engage. Rollers just spin and no grinding. Very frustrating when the hopper is full and can't get the grains between the rollers.

Edit - I use an electric 3/8 drill and works fine.

You can get a set of feeler gauges at an auto supply or hardware store for a couple of bucks.

A credit card is about 0.032" thick. If the grain won't engage the rollers at that gap, then there is something wrong. Severely worn knurling can cause this problem. My 2 roll mill has quite sharp knurling, and has no trouble engaging the kernels at 0.016".

Brew on

 

[brew703]

I don't have a way to measure the gap, I used a credit card as a tool as I've read that was the correct depth however I find it a bit too tight sometimes for my 2 roller set up and the grains don't engage. Rollers just spin and no grinding. Very frustrating when the hopper is full and can't get the grains between the rollers.

Edit - I use an electric 3/8 drill and works fine.

I used a credit card to set the gap on my cereal killer mill and it would not crush/crack wheat grains. So I had to re-adjust and have it set at .036. I may set my gap tighter next time and just use a Vitamix blender or food processor to crush the wheat grains.
I think my next mill will be a 3 roller but that's probably a few years down the line.

 

[OkanaganMike]

Feeler gauges! Just couldn't come up with the name for them. I could see them in my mind and think I even have a set buried away in my tool chest somewhere lol. Anyways, don't know how aggressive the knurling is (presuming they are the teeth on the roller). Don't think they are too aggressive and the mill is only a couple years old Must be that.

 

[doug293cz]

Feeler gauges! Just couldn't come up with the name for them. I could see them in my mind and think I even have a set buried away in my tool chest somewhere lol. Anyways, don't know how aggressive the knurling is (presuming they are the teeth on the roller). Don't think they are too aggressive and the mill is only a couple years old Must be that.

Yes "knurling" is the teeth.

Brew on

 

[wilserbrewer]

My new Kegco 3 roller is knurly!

Not sure the crush is significantly different than my Corona mill....

Can you tell the difference?View attachment ImageUploadedByHome Brew1464997396.705050.jpg

Both appear most adequate IMHO.

 

[doug293cz]

My new Kegco 3 roller is knurly!

Not sure the crush is significantly different than my Corona mill....

Can you tell the difference?View attachment 357230

Both appear most adequate IMHO.

Corona on left, Kegco on right? Agree both look good, but right looks like husks are a little less shredded (at least to me.)

Brew on

 

[wilserbrewer]

Corona on left, Kegco on right? Agree both look good, but right looks like husks are a little less shredded (at least to me.)



Brew on

You are correct sir, I think my sampling method was less than perfect. I believe they are more similar than the samples.

Point being they both work well IMO

I've always just adjusted mills by eye looking at the grist, feeler gauges are a nice idea, but a grain mill isn't like setting valve clearance on a Ferrari....lol

 

[Morrey]

You are correct sir, I think my sampling method was less than perfect. I believe they are more similar than the samples.

Point being they both work well IMO

I've always just adjusted mills by eye looking at the grist, feeler gauges are a nice idea, but a grain mill isn't like setting valve clearance on a Ferrari....lol

Is your mill set a bit under the .032 mark? Perhaps .029 which is where I set mine? I seemed to get a bit more powder than yours, however.

I got great brewhouse efficiency and your bag kept the wort clean so I am not leaning toward changing anything just yet.

 

[Ibrewaletx]

I use a feeler gauge on my roller mill as it has adjustments on either side, if you are not careful you will get a gap that is not even. So, personally I spent a few bucks on Amazon to get a set of feeler gauges and have it set to 0.022" for my BIAB setup with great results.

 

[wilserbrewer]

Is your mill set a bit under the .032 mark? Perhaps .029 which is where I set mine?

I think it may be? I had it set real tight just experimenting at like .02, and the torque required was excessive. As I mentioned, I look at the grist and not so much the gap.

I use a feeler gauge on my roller mill as it has adjustments on either side, if you are not careful you will get a gap that is not even. So, personally I spent a few bucks on Amazon to get a set of feeler gauges and have it set to 0.022" for my BIAB setup with great results.

A slightly uneven gap doesn't really concern me. Jack Schmidling aka "Malt Mills", has sold and manufactured a highly regarded mill for years that is only adjustable on one side...yes it is designed to run an uneven gap lol.
http://schmidling.com/orderpp.htm

Linked below is a very interesting read from "Brew Like a Pro" on malt milling and malt crush....copied below is the first line

"When Rolec set up our new brewhouse, one of the things Harry Klaussner, the brewmaster, did was to adjust the gap settings on our four-roll Kunzel mill. He did this by eyeball. "

http://brewlikeapro.net/maltmilling.html

I found it rather ironic that of the all the homebrew mills tested and crushes analyzed, the mill with the closest output to that of the commercial Kunzel 4 roller mill, was the Corona mill lol.

 

[UndeadFred]

A dime or a credit card is about an ideal feeler gauge for grain milling. I usually go credit card gap and then a little tighter for BIAB on my Corona and it works well.. that might be harder on a roller mill...

 

[AK7007]

For my BIAB filter, I just set my mill gap as tight as I can and then double crush. Flour, basically. The second time is just because I'm dumb and want insurance, it's already flour after the first go-round.

 

[ed007]

Credit card gap. Double crush. Efficiency is consistent at 80% in my BIAB system over the last 10 batches. I use Cereal Killer Grain Mill.

 

[stever1000]

Does double crushing reduce the size on everything on the second pass, or only the material that wasn't crushed fine during the first pass?

 

[wilserbrewer]

Does double crushing reduce the size on everything on the second pass, or only the material that wasn't crushed fine during the first pass?

Double crushing just crushes more of everything I would imagine. With $500 worth of sieves you could answer this question more accurately, but I highly doubt it worth the time and money!

The goal is to crush until the starchy inside of the grain kernel is readily available to the strike water and is easily rinsable in the mash!

Obviously if you have whole or large intact kernels it will be difficult to extract the goodness that is in the INSIDE of the kernel.

The deal on crush gets so over analyzed.....crush till your scared, then crush just a little bit more!

With BIAB, there really is no fear of over crushing IMO.

 

[RM-MN]

Does double crushing reduce the size on everything on the second pass, or only the material that wasn't crushed fine during the first pass?

If you put the grains in one kernel at a time, the second pass won't do anything unless the already crushed kernel is rotated so the crush comes from a different side. If the mill gap was large enough for the kernel to go through without being crushed, it could go through a second time without being crushed too.

When you put the grains through in a bunch for the second pass, some of the grains will be rotated to a different angle which will crush them better and sometimes there will be 2 (or more) pieces trying to go through at the same time so one gets crushed against the other resulting in both being crushed better but a better option would be to have the mill set properly for the first crush.

 

[stever1000]

If you put the grains in one kernel at a time, the second pass won't do anything unless the already crushed kernel is rotated so the crush comes from a different side. If the mill gap was large enough for the kernel to go through without being crushed, it could go through a second time without being crushed too.

When you put the grains through in a bunch for the second pass, some of the grains will be rotated to a different angle which will crush them better and sometimes there will be 2 (or more) pieces trying to go through at the same time so one gets crushed against the other resulting in both being crushed better but a better option would be to have the mill set properly for the first crush.

The reason I ask if when I fill up my hopper, I can usually hear a few grains drop through the rollers before I start crushing. I'm sure it's only a few though so probably not worth the trouble

 

[JONNYROTTEN]

Credit card gap. Double crush. Efficiency is consistent at 80% in my BIAB system over the last 10 batches. I use Cereal Killer Grain Mill.

This exactly only single crush and hover around 75%.I do 25 lbs of grain on average and its easier to add a little grain if I want than run all that grain through a second time