Do these grains look properly crushed?

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Alex4mula

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I heard grain crush significantly affect efficiency. I have done 6 all grain brews (of 24 total) in a Mash & Boil. First and third were so so. Second was bad (low mash temp & stuck). But this month I did three. All three were off in OG with the first one way off. My LHBS crush them for me. I want to show pictures to see if you can tell me how they look. All for 5gal batch. Final OG at fermenter with 4.5-5.2gal. Below are pictures. Tks

First one was a stout. OG was 1.052 and got 1.032 (5.2gal) Fly sparge with water over spoon



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Second was a honey blossom ale. OG was 1.045 and got 1.41 (4.5gal). Batch sparge.

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Third was a brown ale with OG of 1.066 and got 1.045 (5 gal) Batch sparge.

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I agree those are barely crushed if at all. No wonder you are getting such low OG numbers. Volume also has a big effect. If you are doing a 5 gallon batch you need to end up with 5 gallons for your OG to be correct.
 
Thanks all. I had the impression that these didn’t have the best crush but I’m too new to all grain so couldn’t tell. I think I will try to get the cereal killer for Black Friday. It is really the only brewing tool I’m missing.
 
Also, can someone show me pictures of what a good crush looks more or less? Thanks.
 
Here's a fairly decent crush, but it's not quite there yet. For the most part you don't see intact kernels, but there are a few; further, the pieces are fairly large. Now, if you get kernels crushed, that doesn't mean even if they're large that things won't work. The finer the crush, the faster the conversion.

In the case below, I'd run it through the mill again, to catch the few that didn't quite get crushed--or I'd tighten up the mill gap. There is virtually no flour there and while flour isn't necessarily your goal, the lack of it is, to me, an indicator of too coarse a crush.

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Here's a closeup of some of that. You can see from the labels what's what. In each case, those pieces are a sign that it's too coarse a crush.

What you DO want is to have as many intact husks as you can--they help with lautering, i.e., they act as a filter and you want that, lest you get a stuck mash or stuck sparge.

So you're trying to get a fine enough crush to expose the starch in the kernels, but not so fine that you're destroying the husks.

Now, one other thing--people who do BIAB can crush very finely because they're removing the grain from the wort by lifting the bag, rather than removing the wort from the grain with traditional mashing methods.

So, if someone advocates a very fine crush, realize that works for BIAB but can put you at risk of being stuck with traditional methods unless you add back rice hulls to take the place of the now-destroyed barley husks.

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That's a nice crush.
Yep, very nice crush, if the OP takes that as a model, it will serve well. Then it will be a matter of empirical fine tuning to one's own system. Different techniques like BIAB, batch sparge vs fly sparge, etc., can accommodate different degrees of crush. But the fundamental goal remains of intact husks (even if you don't need the filter medium, breaking them up will increase tannin extraction) and a fairly uniform particle size with no unbroken grains and minimal flour.
 
Wow! That is a huge difference! I wonder how I got some sugar out of mines. Thanks you guys. I'm buying my own mill today.
 
Ideally, get one that is adjustable, and get a set of feeler gauges, very cheap from an auto parts store. Then you can find a setting that works for you, and you'll know what that setting is so you can keep it consistent. Otherwise, many people just use a credit card to gauge the gap, that's probably in the right range.
 
Ideally, get one that is adjustable, and get a set of feeler gauges, very cheap from an auto parts store. Then you can find a setting that works for you, and you'll know what that setting is so you can keep it consistent. Otherwise, many people just use a credit card to gauge the gap, that's probably in the right range.

I'm planning to buy this one. Seems to have very good reviews. I have plenty of gauges. Tks

https://www.homebrewing.org/Cereal-Killer-Grain-Mill_p_2310.html
 
and read up on "grain conditioning" to pre wet grain *A LITTLE* with sprayer which helps make husks come through less destroyed, helping filter, since you are not BIAB.

I BIAB. I grind to almost dust.
Conditioning is maybe the best improvement I've made in years in my brewing process. Much better crush and very little dust flying around.
 
I conditioned my grain once. It made almost no difference with my Corona style mill. Of course it works differently by shearing the grains between two plates instead of squeezing between rollers. I may try it again someday no that I have the Cereal Killer.
 
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as usual sorry for my camera , very fine, no stuck sparges with a 10 gallon round cooler and bazooka tube.....WBB, mongoose , your crushes still look coarse to me....

i was always thought crush till you're scared......;)
 
Wow! What a difference a grain grinder can make! Brew yesterday a double chocolate stout (https://www.homebrewing.org/assets/images/Recipe_Instructions_2019/ag99-0104.pdf). Tested the grinder gap at 0.038 and thought it was too small. Then tested it at 0.048 and looked good (pics below). On my last three brews my avg conversion efficiency was 68% and brewhouse efficiency 56%. On this brew my conversion was almost 100% (1.050 on 7gal) and brewhouse efficiency about 89% (1.060 on 5.3gal)! I'm happy! I mashed 75min and fly sparged. Looking forward for next brew :)

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Now you’re rocking! That crush looks 100 times better! I honestly don’t know how some shops let that crush you posted initially go out the door. I’d be embarrassed if I was the shop owner.
 
IMO there is no perfect crush, only the best crush to suit your particular system. If you BIAB then finer is preferred, if you underlet, recirculate and or prefer not to stir your mash then coarser is the way to go. Also remember the finer the crush, the more tannins you will extract.
 
I also bought a cereal killer and love it. Before I started conditioning my malt, I had the gap set to .035 and was able to grind by hand easily. After conditioning, I set the gap to as small as it would go and bought good 1/2” drill with lots of torque. The husks are in much better shape with conditioning.

IMO there is no perfect crush, only the best crush to suit your particular system. If you BIAB then finer is preferred, if you underlet, recirculate and or prefer not to stir your mash then coarser is the way to go. Also remember the finer the crush, the more tannins you will extract.

I’m interested in your comment Bilsch about using a coarser grind when underletting your strike water. I have been looking into some best practices relating to lodo (I noticed you on some of those chats) and one of those practices is underletting strike water into the mash. We have been doing a continuous recirculation but have not done underletting. Is the danger of a finer crush a stuck mash recirculation?
 
I also bought a cereal killer and love it. Before I started conditioning my malt, I had the gap set to .035 and was able to grind by hand easily. After conditioning, I set the gap to as small as it would go and bought good 1/2” drill with lots of torque. The husks are in much better shape with conditioning.

I’m interested in your comment Bilsch about using a coarser grind when underletting your strike water. I have been looking into some best practices relating to lodo (I noticed you on some of those chats) and one of those practices is underletting strike water into the mash. We have been doing a continuous recirculation but have not done underletting. Is the danger of a finer crush a stuck mash recirculation?

Underletting is the best way to exclude the most air from being trapped in your grist when adding the water. Slowly filling from the bottom, the water uniformly displaces the air with minimal bubbles adhering to the crushed grain kernels. However if your crush is too fine then the flour and small particles will hinder the uniform wetting of the grain creating dry pockets and dough balls. With a stirred hido mash this is of little concern but when running a low oxygen recirculating system, trapped air and doughballs are detrimental. In any recirculated system too fine a crush is bad as it will cause stuck mashes, channeling, poor flow, compressed grain bed, low efficiency etc. To get the best grind for recirculated mash, not only do you want a coarser gap but also be milling at a slower RPM. Below 100 is good but below 70 is optimal.

Lastly, for best results when underletting, you want to keep your strike water temperature below the gelatinization temperature of your grain. I usually shoot for an initial water temperature 140 or below, then after filling proceed to your first rest temperature.
 
I conditioned my grain once. It made almost no difference with my Corona style mill. Of course it works differently by shearing the grains between two plates instead of squeezing between rollers. I may try it again someday no that I have the Cereal Killer.
I also conditioned once. 22oz of water in a spray bottle for 22 pounds of grain for a barleywine. Stirred as I spritzed and then let sit for 30 minutes before crushing. My cheap cordless drill gave out almost immediately so I ended up cranking by hand. The resulting grist was super fluffy but I really should have tested it on a smaller grain bill first!
 
I also conditioned once. 22oz of water in a spray bottle for 22 pounds of grain for a barleywine. Stirred as I spritzed and then let sit for 30 minutes before crushing. My cheap cordless drill gave out almost immediately so I ended up cranking by hand. The resulting grist was super fluffy but I really should have tested it on a smaller grain bill first!
That was a weeeee bit too much water! You should only need about 1% of the grain weight in water weight. By 2%, you're getting into serious doughball territory.
 
That was a weeeee bit too much water! You should only need about 1% of the grain weight in water weight. By 2%, you're getting into serious doughball territory.
I know I used the recommended water, and I thought that was an ounce per pound, but it was 7 years ago and I did drink a divine barleywine since then so it is entirely possible that my memory is faulty.
 
Now you’re rocking! I honestly don’t know how some shops let that crush you posted initially go out the door. I’d be embarrassed if I was the shop owner.

I've always believed shop owners have a vested interest in causing low efficiency with their crush (more grain sold). Not saying they all do it, but this one looks pretty blatent. My efficiency increased by 10% just by getting my own mill (my lhbs brings out the pitch forks if anyone dares to touch the gap knob on their mill, they actually watch on surveillance video to make sure you don't)
 
I've always believed shop owners have a vested interest in causing low efficiency with their crush (more grain sold). Not saying they all do it, but this one looks pretty blatent. My efficiency increased by 10% just by getting my own mill (my lhbs brings out the pitch forks if anyone dares to touch the gap knob on their mill, they actually watch on surveillance video to make sure you don't)

Sounds like a crappy shop. I mill to whatever my customers ask. Maybe it's rare because first time customers always have a shocked look on their face when we ask how they'd like it crushed.
 
I'll vote "rare" (and kudos for the effort).
The three shops I've frequented for ingredients all have the customers mill on their own.
Which puts them at the mercy of whatever gap was set...

Cheers!
 
IMO there is no perfect crush, only the best crush to suit your particular system. If you BIAB then finer is preferred, if you underlet, recirculate and or prefer not to stir your mash then coarser is the way to go. Also remember the finer the crush, the more tannins you will extract.
It should be mentioned that the ph has more to do with tannin extraction than the crush in real world application.
 
Underletting is the best way to exclude the most air from being trapped in your grist when adding the water. Slowly filling from the bottom, the water uniformly displaces the air with minimal bubbles adhering to the crushed grain kernels. However if your crush is too fine then the flour and small particles will hinder the uniform wetting of the grain creating dry pockets and dough balls. With a stirred hido mash this is of little concern but when running a low oxygen recirculating system, trapped air and doughballs are detrimental. In any recirculated system too fine a crush is bad as it will cause stuck mashes, channeling, poor flow, compressed grain bed, low efficiency etc. To get the best grind for recirculated mash, not only do you want a coarser gap but also be milling at a slower RPM. Below 100 is good but below 70 is optimal.

Lastly, for best results when underletting, you want to keep your strike water temperature below the gelatinization temperature of your grain. I usually shoot for an initial water temperature 140 or below, then after filling proceed to your first rest temperature.
Also underletting only works well for smaller recirculation systems which is why you dont see it in breweries.. We tried it multiple times at the brewpub and on a 3 bbl system the result is the water is continuously cooled by the grain as it travels upwards from bottom resulting in a mash that was closer to the 163 strike water temp at the bottom and 130s at the top... YMMV and this issue will not be a problem on most homebrew systems unless you dont recirculate or stir and if you do stir its honestly better to just mash in traditionally IMO at that point.

at 5GPM by the time the rims stabilized a grain bill of over 200lbs, much of the conversion was done at inconsistent temps.
 
Also underletting only works well for smaller recirculation systems ... on a 3 bbl system the result is the water is continuously cooled by the grain as it travels upwards from bottom resulting in a mash that was closer to the 163 strike water temp at the bottom and 130s at the top

This is the kind of thing that fascinates me; I mean it makes sense, but I wouldn't have thought of it. And the thought of experimenting multiple times with a grain bill that takes me half a year to go through made me shiver. I think my spleen twitched.
 
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