Rate my crack!

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foundation-crack.jpg
 
Trying (probably in vain) to stay on topic.
After you have mashed, take a big handful of the expended grain, spread it out and look for pearls. Uncracked grain swells up and is very easy to spot, more than 1-2 in your sample and you are probably cracking a bit too coarse.

Coarser cracks are better for recirculation, go too far and you start to loose extract, the coarser the slower you have to sparge, but the faster sparge water will penetrate the grain bed.
Fine cracks have lower permeability (important if you are recirculating) so they will recirculate and lauter slower.
A good crack will depend on what you want from it and how it preforms in your system, but too many uncracked grains is not a good thing.
Mark
 
I usually aim for about 20-30% flour in my crack. This is prob a bit much for a BIAB.

But I also wet my grains before cracking, which gives more intact husks and nice cracked kernels which is perfect for AG lautering

I raised my eff % by a few point just by getting the crack right
 
Mods:

Please rename this thread 'Rate my crush!' as per the correct terminology, 'crack' being an obviously provocative and offensive double entendre.
And remove the exclamation mark while your at it. There''s no need to shout about your crack. (crush).
 
Happy to see that there are not too many photo attachments added to this post...... the pictures running through my head are scary!!
 
I'm not about to touch anyone's crack.
I use an original MillMaster and have my gap set at 1.1 mm, which gives me never less than 90+% mash efficiency.
For your system, it's trial and error, a finer crush isn't necessarily better. MHB is on the money. I
 
What a great thread title. I'll post from my next crush as well
 
Am doing one in the morning, be keen to get some feedback, a;though my beers have generally turmed out ok....never hurts to improve.
 
The big problems with cracking is roller size and speed.

Small roller need slower speed or you will shred the grain

My 50mm knurled rollers run at 180rpm @ 0.9mm .I actually used 0.9mm copper line wire to measure the gap. Copper wire is great because you can see how deep the knurls where when you fed it thru

Note. Copper line wire is VERY accurate with regard to measurement. Its what I use for checking my calipers

100mm rollers can run 500rpm easy

The most honest advice I can give is to play with your mill

Try wetting grains, grab some base malt and adjust the mill and run a handfull thru it. You need to learn about your mill

But also note that if you want to crack Xtal/roast/dark/RB, its different to cracking base malt

You will learn that you will need to adjust your mill for different grains


Enjoy :chug:
 
Regarding wetting/conditioning the malt...

What is a good process/technique and at what rate? I've done it once, without any apparent benefit. As I was weighing out the malt, I transferred about a 250g scoop at a time and gave each scoop about three squirts from a water spray bottle, then turned twice by hand. I used about 200ml of water for 5kg of malt. I left the moist grain sit for about 45-60 minutes before crushing. Didn't notice much difference, perhaps slightly less dust, but that's about it.
 
Ducatiboy stu said:
The big problems with cracking is roller size and speed.

Small roller need slower speed or you will shred the grain

My 50mm knurled rollers run at 180rpm @ 0.9mm .I actually used 0.9mm copper line wire to measure the gap. Copper wire is great because you can see how deep the knurls where when you fed it thru

Note. Copper line wire is VERY accurate with regard to measurement. Its what I use for checking my calipers

100mm rollers can run 500rpm easy


Enjoy :chug:
In a pinch, soft solder also makes a fine, kind of crush gauge. Every garage seems to have a roll, somehow.
 
Couple of catch ups - This is a crack thread not a nipple thread, lets stay On Topic ;)
I have used solder wire to measure gap, well it was more whether the rolls in a fair sized commercial mill were running parallel, the weren't about 0.8mm out (sticky adjuster baring). Just make sure you use Lead free solder, Tin/Silver solder is pretty easy to get, Lead/Tin solder can smear on the rolls and you can get Lead eluting to your next couple of grist's, even if you don't care your yeast might, Lead is toxic.

Another good indication that your crack isn't up to snuff is the taste of the expended grain, chew some if its sweet there is extract going to waste, can be an indication of poor sparging practice, but is often related to crappy cracking. If you are getting big chunks extracting the sugars is a very slow process.

You want even kibble, relatively intact husk, not too much flour and few uncracked grains.
As mentioned above, the gap is only one part of the equation, the speed of the rollers is also very important (better looked at in terms of surface velocity), Bigger wheels give a better crack than do small rollers, even at the same surface velocity (if you plot the rates of approach from top of the roll to point of closest approach for different sized rollers you will see why). The faster the rate of approach, the more likely it is that the malt will (in effect) explode

If you have the time, running the grist through the mill twice (even at the same gap) will give a more homogeneous crush, any oversized bits get wacked on the second pass and your first pass can be just a bit wider so you get less flour, more kibble and bigger husk fragments.

Its funny milling is the first chance we as brewers get to have much of in impact on the brewing process, a good crack is the foundation of a good beer. A foundation means it underpins everything that follows, good cracking leads to faster lautering, higher extract yield and less problematic products (lipids, tannings, minerals...) moving up stream in the brewing process.

Good cracking gives you more and better beer from the same amount of malt, something worth paying attention to. It often gets less attention than it deserves.
Mark
 
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