Check your barley crusher's gap!

I've been fighting efficiency issues ever since starting AG brewing. I had carefully followed the advice of Denny and Bobby and many of the other regulars here on HBT but was still just barely managing 65-70% on my beers.
I'd bought a grain mill and hoped that would finally solve my problem but it didn't so I continued to mess with all sorts of other variables to no avail.

Finally this week I started looking into setting the gap on my barley crusher to a tighter setting even though lots of people say they just use the default with great success. As it turns out the thing wasn't set evenly out of the box. Instead of the expected .039 setting I found it was more like .042 on one end and .044 on the other. I tightened it down to .035 on both sides and even despite some temperature control issues this weekend I hit 83%.

Moral of the story...check the setting with a feeler gauge even if your mill is brand new. It could save you a lot of headache later on. :rockin:

Thanks! Should be getting my mill in the next month or two.

I'm also using the BIAB method and plan to narrow the gap even further.

Just a heads up, a credit card thickness is typically .030", so a slightly loose fit would likely put you close to .035".

got my BC last year and checked the gap right away, .039 on one side and .043 on the other. reset to about .036 and get 72-75%

My barley crusher was also off and out of parallel. Didn't use it before checking. After about 10 or so 12 gallon batches I checked it and it had come out of adjustment again. If I were you, I would add this to your routine brewing calibrations.

Im getting 60% or so using the mill at a small local HBS....I wonder what theirs is set to I may check this out because I'm consistently way below 75%.

So while efficiency is really important, the more important thing is for you to be able to consistently hit the same efficiency time and time again. With that being said, look at grain conditioning. A grain condition with a double decoction I hit 97%. Also learn decoction mashing, you start doing that and crushing really fine with intact hulls I think I crush at about .025.

My mill is set at .028" and I condition the malt. Never get below 90% efficiency but I also make sure mash pH is good and that conversion has finished. I've lautered from 1 to 2 quarts per minute and see a ~3% difference in efficiency, faster being less efficient of course.

I used mine right out of the box and got in the 80's

60% is typical for a LHBS grind. You can "cheat" by grinding it twice, if they let you grind your own.

My BC got 81% yesterday with a 0.036 gap, batch sparged.

I used mine right out of the chute and got an incredible jump in efficiency. 50 or so brews, and an award or two later, I haven't touched the setting. I brew on average twice a month. If you're thinking your beer is suffering because of a coupla hundredths in setting, you ought to be looking elsewhere. Just a thought.

Champurrado said:

I used mine right out of the chute and got an incredible jump in efficiency. 50 or so brews, and an award or two later, I haven't touched the setting. I brew on average twice a month. If you're thinking your beer is suffering because of a coupla hundredths in setting, you ought to be looking elsewhere. Just a thought.

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Chances are your own mill is only a couple hundredths different from wherever you were buying your crushed grain before, yet you say you got an incredible jump in efficiency.

A couple hundredths can make a HUGE difference in your efficiency if it's the difference between some of your grain falling through the mill untouched versus everything being crushed properly.

I'm sure Champurrado meant thousandths. I have also won awards and found that I can sparge faster if I condition the grain before milling at .028" while still getting 90+% efficiency. Regardless of process, please check your mill gap periodically. Along with your thermometers, refractometers, pH meters, etc.

does everyone here who does malt conditioning use stainless rollers, or just blast the shnat out of them with an air compressor to dry?

I just got a mill and did my first batch with it last weekend, came out at 76% after adjusting it to .040 with feelers. That with a hosed up manifold too.

Surprised how many people are running into the 0.030's. I might try 35 next time, I was just concerned I'd get a lot of flour, and didn't want to introduce too much variation into the process on the first self-mill.

I use stainless steel but honestly the malt is so dry by the time I crush it that I don't have any problems at all. The point of conditioning is to make the husks nice and leathery and the endosperm a tad moist so they don't shred and crush very well and don't turn into flour.

A new LHBS opened up near me, and one of the guys from my brewing club loaned his mill to the store to get started. I had been struggling with efficiency as well, and just a better crush on the mill has jumped me from the 60's to the 80's in efficiency.

Was never good with numbers. Yes, thousandths, the really small, tiny ones like in spark plug gaps.

I crushed grain with a rolling pin once and it was one of my best beers by the way.

Not trying to start trouble.......

So if I go into the LHBS and demand to know the milling gap am I going to be an $%#hole? I'm getting 60% only....even on 1.050 batches.

enricocoron said:

So if I go into the LHBS and demand to know the milling gap am I going to be an $%#hole? I'm getting 60% only....even on 1.050 batches.

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No, you should always be able to get that info.

Champurrado said:

Not trying to start trouble.......

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Well, you just did...

Stupid question, measure in inches or metric?

Metric. Aways go for gap in mm, believe me, 1/124 of an inch is really gross to look at. Get a spacer set from sears, it's about 10$.

Or use a feeler gauge. If you have a standard feeler gauge, measure in inches. If you have a metric feeler gauge, measure in millimeters. If you have a combination feeler gauge, take your pick.