Crushing grain for BIAB

[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