My Mill Calibration Experiment

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Jeebas

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After doing my most recent all-grain batch and getting low efficiency - https://www.homebrewtalk.com/f36/low-efficiency-brew-day-question-383643/

I decided to do an experiment with milling grain (I have a Barley Crusher) at a few different settings, mashing for one hour, sparging and then taking a gravity reading.

My process was:

#1 Mill grains (I milled all three batches at the beginning)
#2 Place crushed grains into paint strainer bag in 6 quart pot.
#3 Heat up strike water to 167
#4 Add strike water to pot with grains, maintain temp ~152 degrees for 60 minutes, stirring every 10 minutes.
#5 Pull bag out and let excess wort drain back into pot.
#6 Heat up sparge water to 180 (so it was ready in time)
#7 Once the mash has drained from the bag (under five minutes), put the bag in another pot and add the sparge water. Stir
#8 Let sparge pot sit for 5 minutes
#9 Drain as I did in Step #5
#10 Add sparge pot wort to mash pot wort to make 1 gallon
#11 Chill in ice-water bath to 100 degrees
#12 Take hydro reading.

2 lbs of 2 row mashed for 60 minutes and then sparged with enough water to make 1 gallon (2.5 quarts) at 100% efficiency would be 1.072

The number in parentheses is what I got when changing the Efficiency % to match what I got on the gravity reading.

My findings:

.035" yielded 1.044 - adjusted for temp to 1.048 (66% efficiency)
.032" yielded 1.049 - adjusted for temp to 1.053 (73% efficiency)
.030" yielded 1.051 - adjusted for temp to 1.055 (75% efficiency)

(Since I took the hydro readings at 100 degrees I used http://www.brewersfriend.com/hydrometer-temp/ to adjust hydro readings for temp)

Should I have taken the hydro reading just from the mash instead?

Of course the downfalls of this experiment are that:

#1 This was mash efficiency and not brewhouse efficiency
#2 As I did this on the stovetop with smaller pots it is not representative of what my system will get - concerning issues of if the crush is too fine there being a stuck sparge.

Some pictures of the process -

The grain crushed with the mill set at .035"

DSC_0467.JPG


And here the .032" grain

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And now the .030" grain

DSC_0473.JPG


My mash setup

DSC_0475.JPG


DSC_0487.JPG


DSC_0488.JPG


The sparge water

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Chilling down 1 gallon of wort

DSC_0492.JPG


Afterwards, not wanting to waste anything, I did another mini-mash with 1 lb of 2 row and 1/2 lb of Munich and 1/2 lb of Honey Malt, combined it with the worts from the experiments and boiled around 3.5 gallons (I didn't want to push the limits of my old 5 gallon extract kettle - I didn't feel like trudging out in the snow to fire up the AG rig). Added 2 oz of Amarillo leaf for 60 minutes and then another 1 oz at 5 minutes. I then topped off with water, which unfortunately made the post-boil OG come out to 1.026 :p Very small beer it is! Like I said it was more to not waste anything, we'll see how it tastes.

Thanks for looking!
 
Nice experiment!! People kill themselves over sparging methods, water/grist ratios, other additions--while a little turn of the dial on a mill gives that much extra sugar!
 
This is great! I just received my new mill last week and did I batch Saturday. The instructions say to leave at the factory setting at first, so I checked with feeler gauges to make sure it was where they said. My efficiency was terrible. I'm glad to see this test so that I have a better idea where the gap should be set for my mill. I know it's going to take some dialing in, but this will give me a better place to start.
 
This is great! I just received my new mill last week and did I batch Saturday. The instructions say to leave at the factory setting at first, so I checked with feeler gauges to make sure it was where they said. My efficiency was terrible. I'm glad to see this test so that I have a better idea where the gap should be set for my mill. I know it's going to take some dialing in, but this will give me a better place to start.

I have only used it once (with conditioning the grains) and my efficiency was terrible too. I just made a tweak (to the 1 oclock position) for my batch tomorrow.

Great experiment. I am wondering if I should go a little tighter on the mill and add a few rice hulls to prevent the stuck sparge. I might have to soak some rice hulls tonight.
 
Great experiment. I will use this as a reference once I can get money rounded together for a Barley crusher.

I think it is great that you have this much time on you hands. You think you want to come over and help me dial in my Corona Mill?

I've tried searching for a setting and I know you can't get an exact setting but a general reference. I have heard the width of a credit card but my two previous attempts were very low efficiency. I am going to assume it was a crush or mashing in a bag since everything else was pretty much on par.
 
Nicely done! Would be interested I results obtained with conditioned grains. I use .030 with conditioned grain and have no issues with sticking, tons of big f.uffy hulls. But maybe I should go even lower... Note I uses .030 because I'm too lazy to buy a proper gauge and that is the thickness of a typical credit card....
 
Great experiment. I will use this as a reference once I can get money rounded together for a Barley crusher.

I think it is great that you have this much time on you hands. You think you want to come over and help me dial in my Corona Mill?

Ha! I wish I actually had that much time on my hands. My wife was a little ticked that my little experiment turned into 3 hours Friday night and close to 4 on Saturday - my four year old didn't understand either :p The 1 year old just kept saying "Uh oh"

I've tried searching for a setting and I know you can't get an exact setting but a general reference. I have heard the width of a credit card but my two previous attempts were very low efficiency. I am going to assume it was a crush or mashing in a bag since everything else was pretty much on par.

I used this - http://www.autozone.com/autozone/ac...eeler-gauge/_/N-265p?itemIdentifier=1931_0_0_ - $3 not too bad. I would put the gauge in and then tighten until it the rollers kinda grabbed the blade but I could still pull it out.

I think I am gonna go with .030" for my next AG batch and see how it works on my AG equipment.
 
Great experiment. I will use this as a reference once I can get money rounded together for a Barley crusher.

I think it is great that you have this much time on you hands. You think you want to come over and help me dial in my Corona Mill?

I've tried searching for a setting and I know you can't get an exact setting but a general reference. I have heard the width of a credit card but my two previous attempts were very low efficiency. I am going to assume it was a crush or mashing in a bag since everything else was pretty much on par.

If you are mashing in a bag, you can use a much finer crush/grind. Set that Corona mill until the plates touch lightly without grains in there and then watch your efficiency go up. I expect 80% now with no sparge.
 
Ha! I wish I actually had that much time on my hands. My wife was a little ticked that my little experiment turned into 3 hours Friday night and close to 4 on Saturday - my four year old didn't understand either :p The 1 year old just kept saying "Uh oh"



I used this - http://www.autozone.com/autozone/ac...eeler-gauge/_/N-265p?itemIdentifier=1931_0_0_ - $3 not too bad. I would put the gauge in and then tighten until it the rollers kinda grabbed the blade but I could still pull it out.

I think I am gonna go with .030" for my next AG batch and see how it works on my AG equipment.

Try conditioning (wetting) the grain and close the gap a little more. The wetting will keep the hulls from ripping apart so you still can get a filter bed.
 
I adjusted my grain mill and did something similar yesterday. After adjusting I mashed 1 pound of two row in 1 gallon of water for 60 minutes. I tried to maintain a temp of 152° but that varied from 147°-156°. After the 60 minutes I took a reading of 1.034. Plugging those numbers into Beersmith I end up with 92% mash efficiency which seems high to me. Could the mash hitting the higher temps have caused some of this?
 
I got a BC for christmas. I was consistently getting 75% before having the lhbs mill my grain.
I went to 80% solid at factory settings and changing nothing else on my brew day. I now formulate recipes at 78% just in case. Neat experiment. I was surprised to see people with lower efficiency after getting the BC.
 
I got a BC for christmas. I was consistently getting 75% before having the lhbs mill my grain.
I went to 80% solid at factory settings and changing nothing else on my brew day. I now formulate recipes at 78% just in case. Neat experiment. I was surprised to see people with lower efficiency after getting the BC.

I'm surprised too. I just got a BC and got 90% efficiency with my first batch set at factory settings.
 
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