Grain crush gap?

[Twotaureanbrewing]

In a few days Im getting a small grain mill, I think its The Barley Crusher.

What is the optimum gap between rollers? I've seen .039 thrown around a lot

Thanks!

 

[stpug]

The optimum gap is the gap that produces the best crush for your brewing system and process

....but start at .039 and move up or down based on the results you get. When you figure out the optimum gap that keep note of what it is (measure it) and you should be able to get back there should your rollers move a little bit. You may also find a different gap setting is better for other grains (wheat, rye, etc).

 

[IslandLizard]

Congrats!

+1^, it depends on your system and preferences.
A BIAB brewer has different requirements (finer, bag is the filter) than a brewer who uses a HERMS/RIMS or fly sparges and relies on the husks to keep the grain bed from plugging up.

A regular credit or gift card is around 0.034" thick (they do vary a bit). That's what I used for a long time, but now mill Barley at 0.030". Wheat, rye, flaked goods and other small kernel grain get 0.024". An American Express junk mail card is a good gauge for narrower settings. You can always sand them down a smidgen.

Forgot to say, I mash in a converted cooler with a C-PVC manifold and batch sparge 2x with equal volumes. Mash efficiency is 80-85%. I only need to use some rice hulls when the grist contains a large percentage (>40%) of wheat or rye. Don't mill the hulls!

 

[Owly055]

Most mills have marked settings for initial use. Your process may determine what crush you want. I've crushed as fine as 010. A fine crush results in a rapid conversion. With fine crush, a 15 minute full conversion is doable, though most fast mash types (like me), tend toward 20-30 min. With a fine crush, you will have more trub using BIAB, and may have a slow draining mash tun........ Start out where it is marked, and go from there.

As a matter of interest, a friend of mine who brews 15 barrel batches in his microbrewery adjusted his crusher to a smaller opening, and the result was savings of a bag of grain on each brew....... a significant cost saving over time. It took me nearly 2 years to convince him to try it.


H.W.

 

[bmbigda]

Congrats!

+1^, it depends on your system and preferences.
A BIAB brewer has different requirements (finer, bag is the filter) than a brewer who uses a HERMS/RIMS or fly sparges and relies on the husks to keep the grain bed from plugging up.

A regular credit or gift card is around 0.034" thick (they do vary a bit). That's what I used for a long time, but now mill Barley at 0.030". Wheat, rye, flaked goods and other small kernel grain get 0.024". An American Express junk mail card is a good gauge for narrower settings. You can always sand them down a smidgen.

Forgot to say, I mash in a converted cooler with a C-PVC manifold and batch sparge 2x with equal volumes. Mash efficiency is 80-85%. I only need to use some rice hulls when the grist contains a large percentage (>40%) of wheat or rye. Don't mill the hulls!

so you're curshing your base grains at .030 and then adjusting the rollers and crushing wheat. rye, etc separately?

also - since you use the same mash setup and process as me I figured I'd ask what kind of crusher you have and if you'd recommend it

 

[Firewalker11]

I am using the Cereal Killer Grain Mill and set it as close as it gets for BIAB brewing, about 0.020".

 

[GHBWNY]

A regular credit or gift card is around 0.034" thick (they do vary a bit).

Yes, they do. Mine got quite a bit thinner just before Christmas!

 

[IslandLizard]

so you're curshing your base grains at .030 and then adjusting the rollers and crushing wheat. rye, etc separately?

Yup, I have 2 credit card gauges handy just for that purpose. Mill those small kernels separately. I did a corn mash a few months ago and was surprised how hard those flakes are. I had to narrow that gap even more to get them to crush more the way I like them.

also - since you use the same mash setup and process as me I figured I'd ask what kind of crusher you have and if you'd recommend it

I bought a Monster Mill MM2. Really like it. But I had to buy a 1/2" low speed drill from HF (< $50) to be able to mill grain. The old 3/8" drill I had destined for it was of no use, it just groaned. I only wish I had gotten the 1/2" shaft option on the mill, though, since that's no luxury to drive the monster. I may buy one in the future, but that requires me to buy the whole drive roller/shaft assembly, which is 1/3 the price of the mill.

One thing, make sure both rollers spin freely before each milling session. I got a powerful kickback when the slave (non-driven) roller had seized up after sitting idle for 2 months. Just loosening the side plate a bit freed it up. Must have been dust and/or a slight misalignment.

During that incident I unfortunately bent that 3/8" drive shaft. I managed to straighten it out and it runs fine now, albeit everything mounted on a sturdier and larger, 3/4" plywood baseboard. The drill is now perfectly lined up with the shaft and is not gonna go anywhere anymore. I can still remove it easily for when I need to use it as a drill.

 

[Twotaureanbrewing]

As a matter of interest, a friend of mine who brews 15 barrel batches in his microbrewery adjusted his crusher to a smaller opening, and the result was savings of a bag of grain on each brew....... a significant cost saving over time. It took me nearly 2 years to convince him to try it.


H.W.

Not surprised! 15 barrels is a lot of beer to "experiment with"!

Credit card method is crafty! I have feeler gauges, use them for work sometimes. I mash in a 10 gallon rd cooler, false bottom.

Interesting, I'll play around with gap a little, maybe go a little smaller than .039.

 

[Hemsworth]

I also use a converted cooler, CPVC manifold and 2x batch sparge. I have the Barley Crusher. I stopped brewing for a couple of years and just got back into it in the last couple of weeks. I used to mill at whatever the factory setting was but now I have adjusted it down to .034. My last batch had a target OG of 1.056 and I ended up with 1.062.
Other variables may have come into play but I didn't change anything but the mill compared to my other sessions.