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Question about milling grain

Mashing
#1

So I have been brewing for just over a year…made the switch to all grain after just a few months. Unless I buy my grains pre-milled (closest LHBS is 45 mins away…so I order all my supplies) I have been using a corona mill to crush my grains.

I know that this isn’t as ideal as a roller mill (which I just ordered and will be here within a week) but I’d like to know what is it about the potential of an “over crush” with a corona mill that can hurt efficiency. I hear several say that their efficiency has gone up after purchasing something like a Barley Crusher (which is what I am getting) but why?

The too fine of a crush from a corona does cause a problem with clearing the first runnings at times for me, so it takes a little long to vorlauf, that I understand.

Thanks!

#2

Efficiency problems are usually caused by one of two things:

  1. Bad crush. Not a problem in your case.

  2. Poor volume measurement or not collecting all your wort. More likely.

With a very fine crush, a lot of flour is generated, so that in a “traditional cooler mash tun” setup, it can form a clay-like layer on top of the mash and significantly slow or stop flow of the liquid wort out of the mash tun. This is also known as the “stuck mash” or “stuck sparge” phenomenon. You need to take care to collect all the wort and don’t leave more than about a quart in the mash tun.

However, if you brew in a bag (BIAB), then this is more of a moot point because the grains are all squeezed to get all the goodness out, regardless of how much flour is in the grains.

Regardless of mash method, you need to nail your volume measurements. If you want 5 gallons after the boil, so that you collect 6 gallons before the boil (losing about a gallon due to evaporation during the boil), then if you are batch sparging, you want to collect close to 3 gallons from the first runnings and 3 gallons from second runnings. If you are fly sparging or BIAB, then just make sure you get 6 gallons or whatever you planned on getting for pre-boil exactly. If you plan on getting 6 gallons but accidentally collect 5.5 gallons or 7 gallons or something like that, this will screw up your efficiency calculations. You need to nail your volume measurements before the boil.

So… bottom line is, I don’t think a Corona mill can hurt your efficiency at all, if you collect all your wort. In fact, it should honestly HELP your efficiency to generate more flour, which is what I would expect from Corona. The only way it could hurt is if you don’t bother to collect all your wort, e.g., you intend to collect 6 gallons but give up with the stuck sparge after 5 gallons or whatever. That will hurt efficiency if you don’t collect all of your wort. Nail those volumes.

:cheers:

#3

Thanks for the reply. Let me present a scenario to you based on my last brew.

Grain bill for IPA was:

6 lbs 2-row
5 lbs California Select
8 oz Crystal 40
8 oz Carapils
5 oz German Munich
4 oz Melenoiden

10 gallon cooler with false bottom. Mashed at 152 degrees for 60 mins. Fly sparged with 180 degree water, and I tried to time the run off at about 1 qt / 2.5 mins., so the sparge took a little over an hour.

I collected a lot of wort…stopping after about 7.5 gallons. What came out at the end of the mash tun was about 1.015 or so, therefore I knew that I had pulled most of what I could.

Bottom line is that I have about 6 gallons in my 7.9 gallon Spiedel, with about .5 gallons of that being trub at the bottom.

OG, after the boil was 1.059. According to the calculator at brewersfriend.com, that puts me at about 71%, if I recall.

It just seems that, with the gravity of the last runnings of the wort being that low I should have hit better numbers. Or am I not factoring something else in?

#4

In your case, the efficiency issue isn’t likely to be from the mill. The problem with the Corona mill is that it shreds the husks, which results in a poorly draining grain bed. If that results in uneven flow of the wort through the bed, then it is contributing to poor efficiency. But generally, poor flow is much more likely to be due to geometry considerations with your lauter tun. As you are fly sparging, you might be suffering from channeling, which leaves high-sugar concentrations in some of the grain bed, while other parts are sparged effectively. Or it could be that your volume measurements are off. That is probably the most common reason for strange efficiency results.

You might want to think about other ways of sparging. Fly sparging makes a lot of sense for very high batch volumes, but less so if you are only making 5-10 gallons. Batch sparging works better for most homebrewers, and if you already have a cooler with false bottom, you don’t need to get any additional equipment. A lot of brewers love the easy of BIAG, which makes a huge amount of sense if your batch size is 5 gallons or less.

#5

Hmm… I am not a fly sparger so I am just coming up with this now but it appears to me that if you use a little less grain and aim to hit 1.010 by the end of the sparge then your efficiency will increase all by itself. You are using more grain than you need to and thus wasting sugars that way. Aim for 80% efficiency next time when designing your recipe and all your problems might be magically resolved. Not easy to explain especially as I type this on my damned Kindle…

#6

Unfortunately not necessarily true. I used to fly sparge, and that is only one of the issues involved with it. Fly sparging (when you are making big batches) is the way to get the best efficiency IF you are doing everything right. But it is a hard method to tune in. My life got much easier when I discovered how to batch sparge, and my efficiency increased.

#7

[quote=“rebuiltcellars”]
Unfortunately not necessarily true. I used to fly sparge, and that is only one of the issues involved with it. Fly sparging (when you are making big batches) is the way to get the best efficiency IF you are doing everything right. But it is a hard method to tune in. My life got much easier when I discovered how to batch sparge, and my efficiency increased.[/quote]

What have you found to be an efficient way to batch sparge?

#8

[quote=“Catch22”][quote=“rebuiltcellars”]
Unfortunately not necessarily true. I used to fly sparge, and that is only one of the issues involved with it. Fly sparging (when you are making big batches) is the way to get the best efficiency IF you are doing everything right. But it is a hard method to tune in. My life got much easier when I discovered how to batch sparge, and my efficiency increased.[/quote]

What have you found to be an efficient way to batch sparge?[/quote]

http://hbd.org/cascade/dennybrew/

The key to high efficiency when batch sparging is to drain the cooler as completely as you can before adding the water for the second sparge. Also, attempt to get roughly equal volumes out for both sparges.

But the #1 thing for any kind of sparge method is to mill the grain a fine as you can without the risk of getting the sparge stuck. If you use a roller mill and condition the grain before milling, you can set the rollers very close and still get big husk pieces to create a well-draining grain bed. Depending on the grain bill, you can expect efficiencies of anywhere from 75 to 90%. That isn’t in the league of what the big commercial breweries get (the brewmaster would likely get fired if he didn’t get 95+% on a regular basis), but you don’t need to tune everything to the nth degree either.

#9

I fly sparge so I don’t believe the inherent problem is that. As long as you keep 2" of water on top of the grain and hit about an hour you are fine. But couple things:
Fly sparging often requires the sparge water to be treated as a buffering agent since it takes such a long time. If water isn’t treated the pH can be out of whack. Are you dong this?
Second, are you taking preboil readings? There is a major difference between mash efficiency and brew house efficiency. For example, I could get a mash efficiency of 60% but boil like mad and reach my targeted OG, therefore bumping my brewhouse efficiency. This would make it look like I had great mash efficiency if you didn’t take a reading to see about preboil.
Now, high efficiency isn’t really all that great. Intact, there is a lot of info out there that suggests too high efficiency is detrimental to the beer. And personally, if I’m hitting my OG at end if boil I’m happy (unless of course I’m boiling for extra time to do so).

Here is a good read on efficiency

http://braukaiser.com/wiki/index.php?ti ... Efficiency

Edited because stupid auto correct on tablets.

#10

[quote=“Loopie Beer”]I fly sparge so I don’t believe the inherent problem is that. As long as you keep 2" of water on top of the grain and hit about an hour you are fine. But couple things:
Fly sparging often requires the sparge water to be treated as a buffering agent since it takes such a long time. If water isn’t treated the pH can be out of whack. Are you dong this?
Second, are you taking preboil readings? There is a major difference between mash efficiency and brew house efficiency. For example, I could get a mash efficiency of 60% but boil like mad and reach my targeted OG, therefore bumping my brewhouse efficiency. This would make it look like I had great mash efficiency if you didn’t take a reading to see about preboil.
Now, high efficiency isn’t really all that great. Intact, there is a lot of info out there that suggests too high efficiency is detrimental to the beer. And personally, if I’m hitting my OG at end if boil I’m happy (unless of course I’m boiling for extra time to do so).

Here is a good read on efficiency

http://braukaiser.com/wiki/index.php?ti ... Efficiency

Edited because stupid auto correct on tablets.[/quote]

I use 5.2 pH Stabilizer with both my mash water. 1 Tablespoon for every 5 gallons. Should I be adding to my sparge water too? I take reading both pre and post boil, and I actually didn’t get a huge difference. My preboil was, if I recall, 1.056, and my post boil was the 1.059. After an hour of a full boil, that doesn’t seem like a big enough difference, does it?

#11

I’ve never used it but my understanding is this stuff is not a magical substitute for achieving an actual pH near 5.2. If you are using your tap water you really need to know the alkalinity of your water before you can be sure your pH is where it needs to be for proper conversion.

#12

Matt’s correct about the 5.2 stuff. That crap is pointless.

As far as your preboil to post boil OG. You only gained 3 gravity points over an hour? Something doesn’t seem right there. Did you top off with water?

#13

Yep…it seems like the only people who claim it works are those who don’t actually check their pH! Plus, I found it added weird flavors to my beer.

#14

[quote=“Loopie Beer”]Matt’s correct about the 5.2 stuff. That crap is pointless.

As far as your preboil to post boil OG. You only gained 3 gravity points over an hour? Something doesn’t seem right there. Did you top off with water?[/quote]

No…I did not top off with water. I know that at least a gallon boiled off, and I was using a refractometer, rather than a hydrometer, for my readings.

It seems really odd to me, too.

#15

I got wild variations in SG during the boil with my automatic temperature correcting (ATC) refractometer until I realized that although it kinda’-sorta’ corrected for temp, it worked better if I cooled the wort sample to room temp. I dip out a tiny sample with a thick-bottom glass and pour it into a second similar glass after a few seconds, then let the sample sit in the second glass for about a minute before dibbling a few drops onto the sample plate. Read the sample immediately. If it sits on the refractometer for a while the SG will increase due to ???

Letting the sample cool brings the reading in line with a large, cooled sample in a hydrometer, but does it in a fraction of the time required to cool a sample for a hydrometer.

Once fermentation begins you must correct for the effect of alcohol on the refractive index. There are plenty of sites that will do the arithmetic for you. I use a hydrometer for SG readings starting about two weeks after pitching, not because it’s more accurate, but because I like to taste the beer.

#16

[quote=“Old_Dawg”]I got wild variations in SG during the boil with my automatic temperature correcting (ATC) refractometer until I realized that although it kinda’-sorta’ corrected for temp, it worked better if I cooled the wort sample to room temp. I dip out a tiny sample with a thick-bottom glass and pour it into a second similar glass after a few seconds, then let the sample sit in the second glass for about a minute before dibbling a few drops onto the sample plate. Read the sample immediately. If it sits on the refractometer for a while the SG will increase due to ???

Letting the sample cool brings the reading in line with a large, cooled sample in a hydrometer, but does it in a fraction of the time required to cool a sample for a hydrometer.

Once fermentation begins you must correct for the effect of alcohol on the refractive index. There are plenty of sites that will do the arithmetic for you. I use a hydrometer for SG readings starting about two weeks after pitching, not because it’s more accurate, but because I like to taste the beer.[/quote]
Refractometers are fast, convenient and accurate, but there are some tricks to using them. Don’t trust the automatic temperature compensation too much, as Old Dawg says, they work better when the wort is cooled first.

And if left to sit on the refractometer a while, the SG will increase. This is due to the water evaporating - resulting in concentration of the sample. This can also be minimized by cooling the sample before taking a reading; at room temperature the evaporation happens more slowly.

#17

did you know that ATC corrects for the temp of the instrument, not the wort?

#18

did you know that ATC corrects for the temp of the instrument, not the wort?[/quote]
Yes, I did know that. You would think that it doesn’t matter much, because the wort will cool to the temperature of the instrument pretty quickly. But surprisingly, it only takes a few seconds for enough evaporation of the wort to occur to throw off the reading when the wort is hot. You can actually watch it happening.

#19

do this to improve your crush

http://www.brewersfriend.com/2010/01/16 ... ditioning/
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