My LHBS suggest .030" for a two roller. Anyone have other opinions?
Depending on your system you may be able to go a bit tighter to increase your extract efficiency but .030" is good spot to baseline at.
You might also need to loosen it up a bit if you use wheat often. The kernels are plumper and can cause the dead wheel (assuming your mill doesn’t drive both rollers) to stop. You just need to play with it.
Have fun!
Paul
Thanks! My upcoming batch actually has 60% wheat. Considering that maybe I will go a bit above .03 and see what I get.
I’m at 0.028" with a 3-roller.
You can go TIGHTER with wheat, the kernels are much SMALLER than barley. I sometimes use 0.025" for grists with a portion wheat, 0.032" for most grists, with a 2- roller MM2 PRO with 2" rollers. But I find anything in the 0.030" range is a good all purpose starting point. It will all depend on the rest your system in the end, what kind of grind gives you the best extraction with the fewest problems.
[FWIW the textbook answer (literally, from Briggs, et al., Brewing: Science and Practice) is that the useful range for 2-roller mills is 0.024" to 0.039". And yet homebrew mills are invariably factory set at 0.045", and most LHBS mills are set there. No good can possibly come of this. BTW regarding this textbook information, technically speaking, there is no such thing as a 3-roller mill, and 2-roller mills are only found in small units like home- and pub brewing. So it’s citing the appropriate range for everything we’ll ever use. Homebrew 3-roller mills are considered just 2-roller mills with a feeder roller along for the ride.]
I’ll never deny I might be wrong. I was thinking wheat was a bit plumper. I’m likely thinking of a different grain.
I do know wheat is quite a bit harder and has a bad habit of jamming my mill on way too regular a basis.
Paul
My JSP malt mill is set at .040
Thanks for the feedback. Probably going just stick with .03 and go from there.
+1. I just moved back from .030 to .040 based on my current set up. I now HERMS recirc with an InfuSSion mashtun and used to use a bag and could get away with a more powdery type crush.
It depends on your lautering system. Not all are the same. Start at what was recommended.
If you do brew in a bag, crank it all the way down.
I use a 10 gallon round cooler with a braided hose as well as a bag.
+1 as well. My Crankandstein mill that I purchased about 8 months ago came factory set at 0.030". That was a bit too tight as I got a lot of flour from the first use and stuck the mash. I reset it to 0.040", confirmed with a feeler gauge, and everything is fine. My efficiency went up about 5% with this mill and setting. My old mill was a preset JSP that was 25+ years old that I bought from a LHBS that went out of business and the rollers were really worn. Unfortunately, as I mentioned previously, JSP is out of business as a fire destroyed his shop a couple years ago.
I always get a kick out of reading Jack’s thoughts on the matter of crush size. I cut and pasted it here:
CRUSH QUALITY
The use of the word “quality” is subjective and has no quantifiable meaning in this application. What one MEASURES is the statistical distribution of the grist size, viz., the percentage of the grist that passes through an industry standardized set of sieves. There are published examples of grist analysis that are considered typical of what a large commercial brewery should look for but there is no such thing as a single standard of quality that is ideal for every system. Unless you run malt through a flour mill or coffee grinder, there is no way one can look at the grist and determine it’s “quality”. The proof of the pudding is the extract YOU get in YOUR system and not some perceived idea of “crush quality”.
Furthermore, it is impossible to over-crush malt in a JSP MALTMILL. This is particularly true of the pre-adjusted mill and virtually true on the adjustable mill because the spacing is fixed at one end to the same value as the pre-adjusted mill. The mill may be adjusted to produce a finer grist than might be ideal for a particular system but it will NEVER be finer than the so-called “textbook crush”.
The issue of “husk damage” is also a common subject of concern among the pundits but a lack of understanding of the problem has produced much unnecessary concern. The husk provides the material for the filter bed that clears the wort but the wort does not travel through a husk, it goes around it and it is the edges that snatch and retain the particles filtered. Up to a point, the smaller the particles are, the more efficient will be the filtering. We get into trouble when the mill pulverizes husk into particles so small that they can not be distinguished from the starch particles. No modern multiple roller mill is capable of doing this so it is really a non-issue unless we are dealing with mills designed for another purpose or with a single roller.
There are reasons why grist analysis is important to megabrewers and it is based on the bottom line of the P & L statement. What is best for the megabrewer is not necessarily best or even good for the homebrewer. One can achieve the textbook type grist analysis with an adjustable MALTMILL or something that looks very little like it with the “pre-adjusted” MM but I defy anyone to prove that the beer they make is in any way measurably different. Fact is, the fixed mill grist is more forgiving and easier to mash, lauter and extract than the finer crush that the other can achieve.
One final point on adjustable mills is worth putting on the table. It is frequently suggested that the one sided adjustability of the MM is a limitation when in fact, this is actually the key to the so called “text book crush”.
If you look at the oft published drawing of a six roller mill, you will note that the roller spacings are about .050", .030" and .012" from top to bottom. It just so happens that, when an adjustable MM is set to near contact at the adjustable end, one gets those same numbers at the fixed end, center and adjustable end respectively. The end result is that the random distribution of grain across the length of the rollers provides about the same grist distribution as a six roll mill.
This situation is enhanced as the roller length is increased and probably could not be reproduced in a mill with shorter rollers. I also doubt that short rollers could be operated at such a skew without binding and/or damage to the bearings.
I repeat my challenge to anyone to prove that they get better beer using any mill out there than from a fixed MM. Not surprisingly, I hear from people who have had mills for years who call to ask what the knob on the side is for or who know what it is for but have never adjusted the mill since receiving it.
HOWEVER, to silence the skeptics, we do offer a mill, (Model AA) adjustable at both ends, for a nominal additional cost but few of them are willing to put their money where their mouth is.
Jack Schmidling Productions, Inc.
Went with about .03 for the first batch and all went well. I was very surprised not to get a stuck sparge. Got 80% mash efficiency so I’m good with it.
This article describes the ASBC method to adjust your mill in order to get the maximum extract. For a 2 roller mill, all you need is a #14 seive, which costs $20 shipped.
When you crush, you want to be left with approximately 50% of the grain in the sieve and the other ~50% in the pan (where the total - 100%.) It’s not difficult or expensive to set your mill correctly with this method.
If you trust someone who’s apparently done it for you… In their Water book, Palmer and Kaminski report that, taking the ASBC definition of coarse grind, 75% remaining on a No. 30 sieve, the closest approximation to this result on a two roller mill was found by Kai Troester to be had with a gap setting of 0.8 mm, ~0.32 in. FWIW, at least as a point of reference.
All mills are not alike, though. This is why the gap number isn’t always ideal. My mill has knurled rollers and the gap I use is not the same as what I use on a smooth roller mill at my local homebrew shop.
True. Some day I may get a sieve set and see what I’m getting just for giggles. But more important to me is the practical result, by which I’ve dialed mine in by trial and error. Coincidentally, to 0.032 in. Which as you rightly point out would not necessarily translate to everyone else. I suspect that not only surface treatment of the rollers, but also roller diameter makes a difference. My 2 in. rollers no doubt pass the grain through differently than the more typical 1.5 in. homebrew rollers, or 6 in. rollers on a pub brewery’s mill.
Though it would be fun to run an assay, even with the information I wouldn’t change my gap gained thru [painful] trial and [lots of] error on my system using my mill, processes, volumes, pump flow setting, etc. I would not adjust the mill gap because a textbook tells me this is the ‘proper’ mill setting and I’m doing it wrong. Great starting points that weren’t optimized with me and my cobbled together system in mind.
Having said that, it makes me wonder how many homebrewers experience a stuck lauter because of excessive flow rate yet blame it on the mill setting. Grain bed compaction is probably to blame for a stuck lauter more often than not as a result of high flow pumps not throttled back enough. These pumps we use (Chugger, March, Riptide, etc) are way over rated for the task IMO. …and a ball valve fitted as a throttle is pretty difficult to set repeatably for a desired flow. I’ve resorted to a digital caliper to set my pump’s output linear flow valve (I have been using 5/32” but I’m planning on using 9/64” Fri).
- 1,000,000
BrewBama, you first alerted me to a post on Dave Miller’s website that helped me confirm, mathematically, that my velocity (NB: it’s velocity, not flow rate, that matters) as empirically established was correct. That rate, for me, and it’s going to be in the ballpark for most homebrew systems, is around 0.25 in/min. Which for me is about 0.67 qt/min. (Depends on geometry and loading, but it’s all in a range.) Almost all homebrewers running systems with a recirculating pump are so far exceeding this as to be absolutely terrifying. There’s no adjustment in crush that will save your @$$ if you’re running your pump like that. (No, I don’t have a pump. Gravity still works in my bit of spacetime. And I still have to rely on my use of a simple bottling bucket spigot, not a 1/2" ball valve, throttled almost to closed position, as the outlet on my lauter tun, to sufficiently restrict flow.) Slow your roll, people.