Grain crush/mill question.

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agentbud

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I recently brewed a Hefeweizen via BIAB (Ed Worts recipe). The bulk of the grist was wheat so I asked the HBS (online) to run it through their mill twice (they said their mill was set to .045). When I received the grains, they still did not look crushed enough so I used my kitchen food processor to further grind it up. Putting 3 or 4 scoops in at a time I hit the pulse button a few times. The result was definitely a finer crush. Not as far as flour but chopped pretty fine with maybe 20% as fine as sand. Other than wheat, the only other grain was pilsner which I also ran through the processor.
Beersmith said that my OG should have been 1.054. My actual OG came in at 1.037. All my other numbers such as water and mash volumes were spot on and my FG came in right where expected at 1.013. The only other thing I did different is that I added 1/2 lb rice hulls. Even though I BIAB I was thinking that maybe the rice hulls would improve the drainage from the bag.
Any thoughts on what may have caused the low OG? Any reason it might have been caused by running the grains through the food processor or the addition of the rice hulls?

Thanks, Mike
 
While acknowledging that roller knurling varies so mill gaps aren't 100% comparable, I run my new-ish Cereal Killer with an 0.032" gap for barley malts, and I run my old Barley Crusher with an 0.025" gap for white wheat malt. An 0.045" gap on either mill would barely touch the barley and even less the wheat.

So...while kudos for the effort, I'm betting your entire grain bill needed more abuse before mashing to get better numbers.
As for the rice husks, I use them all the time - I presoak and drain them before layering the FB with them so they don't mess with the fluid volumes at all - and have never seen a negative effect on yield...

Cheers!
 
Did you sparge? Sparging affects efficiency.

Also, your FG did not come right where expected because if you start with a lower OG, given a certain apparent attenuation you should end up with a lower FG as well.

If starting from 54 points you were expected to end up with 13 point, that means your yeast was expected to have 72% apparent attenuation.
If you started from 37 points you should have ended up with around 7 points given the same apparent attenuation.

This means that you had both a lower OG and a lower attenuation than expected.

In my scarce experience and humble opinion, that might be due to a problem in mashing: incomplete conversion of starches and/or too high temperature of mashing which resulted in a less fermentable than expected wort.

Others will help you more than my poor self, I suggest giving this additional information about the mashing schedule and the sparging.
 
I recently brewed a Hefeweizen via BIAB (Ed Worts recipe). The bulk of the grist was wheat so I asked the HBS (online) to run it through their mill twice (they said their mill was set to .045). When I received the grains, they still did not look crushed enough so I used my kitchen food processor to further grind it up. Putting 3 or 4 scoops in at a time I hit the pulse button a few times. The result was definitely a finer crush. Not as far as flour but chopped pretty fine with maybe 20% as fine as sand. Other than wheat, the only other grain was pilsner which I also ran through the processor.
Beersmith said that my OG should have been 1.054. My actual OG came in at 1.037. All my other numbers such as water and mash volumes were spot on and my FG came in right where expected at 1.013. The only other thing I did different is that I added 1/2 lb rice hulls. Even though I BIAB I was thinking that maybe the rice hulls would improve the drainage from the bag.
Any thoughts on what may have caused the low OG? Any reason it might have been caused by running the grains through the food processor or the addition of the rice hulls?

Thanks, Mike
What temperature was the sample when you measured the OG? If it was warm, anything above room temperature, then you need to adjust the reading to get a true measurement.
 
The bulk of the grist was wheat so I asked the HBS (online) to run it through their mill twice (they said their mill was set to .045). When I received the grains, they still did not look crushed enough so I used my kitchen food processor to further grind it up.

With the mill gap at .045 the wheat was barely cracked and it probably didn't improve much going through a second time. Since wheat is harder than barley your food processor probably didn't mill it up fine enough either. Before you brew another batch you need your own grain mill and since you are BIAB, get a mill that works well for that. This is the one I use and have had to adjust recipes way down because my efficiency is way higher than the recipes are written for. Set it tight and see the difference.

https://www.ebay.com/itm/Grinder-Co...161995?hash=item3ff13bb64b:g:ScoAAOSwa3BgEjOk
Once you have your own mill you can buy grains in bulk if you want and the savings will quickly pay for the mill.
 
Did you sparge? Sparging affects efficiency.
No sparge - it was the BIAB method which I have done several times with no efficiency issues

If starting from 54 points you were expected to end up with 13 point, that means your yeast was expected to have 72% apparent attenuation.
If you started from 37 points you should have ended up with around 7 points given the same apparent attenuation
Understood. I did not know that.
 
What temperature was the sample when you measured the OG? If it was warm, anything above room temperature, then you need to adjust the reading to get a true measurement.
OG was taken at pitching temp which was around 68-70 degrees
 
With the mill gap at .045 the wheat was barely cracked and it probably didn't improve much going through a second time. Since wheat is harder than barley your food processor probably didn't mill it up fine enough either. Before you brew another batch you need your own grain mill and since you are BIAB, get a mill that works well for that. This is the one I use and have had to adjust recipes way down because my efficiency is way higher than the recipes are written for. Set it tight and see the difference.

https://www.ebay.com/itm/Grinder-Co...161995?hash=item3ff13bb64b:g:ScoAAOSwa3BgEjOk
Once you have your own mill you can buy grains in bulk if you want and the savings will quickly pay for the mill.
Yeah, I have been thinking hard on getting a mill and this might just push me over that hill
 
While acknowledging that roller knurling varies so mill gaps aren't 100% comparable, I run my new-ish Cereal Killer with an 0.032" gap for barley malts, and I run my old Barley Crusher with an 0.025" gap for white wheat malt. An 0.045" gap on either mill would barely touch the barley and even less the wheat.

So...while kudos for the effort, I'm betting your entire grain bill needed more abuse before mashing to get better numbers.
As for the rice husks, I use them all the time - I presoak and drain them before layering the FB with them so they don't mess with the fluid volumes at all - and have never seen a negative effect on yield...

Cheers!
Thanks day_trippr. Always enjoy reading your replies. I'll prolly get my own mill for next time
 
Once you have your own mill you can buy grains in bulk if you want and the savings will quickly pay for the mill.

This has been my thought on this matter as well. Depending on what grain I use or which shop I hit locally, I can get base grain for $1.80 to $2.25 per lb. That same grain is in the $1 per lb range in a 50/55 lb sack. So 100 lbs of grain, a $100 mill is paid for. That is on top of the consistency and efficiency boost from controlling my mill gap, and avoiding the hassle of running to the store for every batch. Local shops also have a better variety of bulk grains than bulk or in 10# bags.
 
I'll prolly get my own mill for next time

I got a Cereal Killer from Adventures in Homebrewing for Christmas. Since then my efficiencies have gone from 55-65% up to 80-85%. I set my gap at about 0.029". Full volume BIAB w/ Wilserbags.

I've been brewing all grain w/ various systems since 1996, and have never seen efficiencies this high. Get a mill, and buy base grains in bulk to pay for it!

K
 
I got a Cereal Killer from Adventures in Homebrewing for Christmas. Since then my efficiencies have gone from 55-65% up to 80-85%. I set my gap at about 0.029". Full volume BIAB w/ Wilserbags.

I've been brewing all grain w/ various systems since 1996, and have never seen efficiencies this high. Get a mill, and buy base grains in bulk to pay for it!

K
Do you leave it at 0.029 regardless of the type or size of grain (ie barley vs wheat)?
 
Do you leave it at 0.029 regardless of the type or size of grain (ie barley vs wheat)?

Yes, so far. I've done a few brews, settling in w/ my measurements and numbers before changing anything. I've used barley and rye, no wheat yet. Dump it all in, and pull the trigger on my drill!

K
 
If starting from 54 points you were expected to end up with 13 point, that means your yeast was expected to have 72% apparent attenuation.
If you started from 37 points you should have ended up with around 7 points given the same apparent attenuation.

54 -> 13 = 76% Apparent Attenuation
37 -> 7 = 81% Apparent Attenuation
 
I ended up with a FG of 12 so I guess that gave me an apparent attenuation of 68% (67.5%), and if I was to maintain the attenuation of the original calculation, that FG would have needed to drop to about 9, correct?

54 -> 13 = 76% Apparent Attenuation
37 -> 9 = 76% Apparent Attenuation
 
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