What grind size to use on my malt mill?

Is there a standard size to use or does it depend on the moisture levels of the grains or on the kilning levels (if more kilned/roasted less crush?) ?

Does anybody know if the size of crush is not standard on what does it depend?

 

I just got a grain mill myself, I've been told "standard" crush is around 0.039". Sometimes folks who do BIAB go for a finer crush as you can't really get a stuck sparge. I plan on starting at 0.039" to see how it goes.

 

I have a monster mill that is set at 0.031. Works like a champ. I use a cooler MLT with a bazooka screen, and have yet to have a stuck sparge. I'm usually in the 80+% efficiency range for my mash.

 

I use biab too and I like to consider yeastylad's idea of maybe crushing finer as long as it doesn't slip through the bag because we don't run off! Also I don't do mash out so less risk of tannin extractions too.

 

There's really no default size to use, it depends on your setup and process as your lautering can varying as a result of your equipment. I use a bazooka screen and use around 0.030in (credit card thickness) for barley through my Monster Mill 2. When using wheat however, I have to set the gap tighter as the wheat kernels are smaller, so I tighten it up by eye. Can't say exactly what the gap setting is but I believe it's around the .020(something) range. Just got tired of using the feeler gauges and learned to eyeball it. I haven't used rye but also read others using a tighter gap for rye. I basically get 86% efficiency nearly every time for my ales and 79% efficiency every time for my wheat beers.


Rev.

 

The optimal gap will be affected by the knurling specific to each mill, so a reliable "standard" probably can't exist.

If one has a mill, it usually comes with a recommended gap, a good place to start.
fwiw, the recommended gap on the infamous Barley Crusher is .039".

Cheers!

 

I crush .45 on my system. Certainly coarser than most but I hit 80% every time. Works well for me.

 

I always condition my grain (read this if you haven't, it'll change everything!!!), which allows a finer crush while still keeping the husks mostly intact. In doing so, I now set my gap to 0.54mm (about 0.0216" or 21.6 mil) for all of my grain except wheat. Since wheat kernels are smaller, I close the gap to about 0.41mm (0.016" or 16 mil) and condition/crush those separately.

These sound like crazy tight gaps, but I've never had a stuck sparge or any other issues. The only side effect I've seen from this is a better mash efficiency!

 

+1 on conditioning grain. I did this two brews ago and will never crush unconditioned grain again. Got a much finer grind with great husk integrity.

All the Best,
D. White

 

Did either of you notice improved numbers from conditioning the malt?

 

Yes absolutely. Not so much from the conditioning itself, but from being able to mill the grain finer. I jumped from about 70-73% to 85%+ mash efficiency.

 

Here is a very good article on how to know exactly what is the proper gap for your mill and malt. It does require extra equipment.

Brew Like a Pro/Malt Milling

 

Milling finer is the biggest factor but with a conventional mash tun you need the intact husks to help create the filter bed. Conditioning toughens the husks so they don't get all torn to shreds.

 

Yes sorry, that's what I was implying - that conditioning allows to mill the grains finer while still achieving a desirable retention of husk integrity for filtering the mash during lautering.

 

I always show this pic from my old Corona mill which i think did a pretty good job milling...this is more or less what i aim for. All the grains are crushed, there are mostly large husks left for filtering but all the insides are exposed with minimal flour.

 

I started conditioning my malt about 2 years ago. I get about 9% more efficiency over just running them through my Barley Crusher. Conditioning does make the husk more pliable allowing it to stay more intact. This helps with the lauter by giving your mash a much better filter bed.

 

What water you use to condition your malt? Your treated water?

 

It shouldn't matter what water you use to condition the malt because there should be so little of it that it won't affect the mash. You aren't soaking the grains, just wetting the husks enough to make them tough.

 

It makes sense. Does it help to condition the malt when doing BIAB?

 

I've been meaning to start doing this. Thanks for the reminder. Any advice that isn't on the page you linked?

 

I just use a spray bottle and spritz the grain and mix it with my hand, spritz again and mix. I do this until it feels like a slightly damp paper towel. You don't want it to be sticky, then it will gum up your rollers.

 

I wouldn't think so since the bag is the filter and you probably aren't doing a fly sparge. I think it would be counter productive for biab. Using the bag allows for a fine crush while conditioning is for a more normal crush. Just my guess though.