Dialing in Monster Mill...

[jmark]

First two brews with the mill had lower efficiency than expected... Part of that was bad calc on amount of strike water but also probably due to my crush... The attached are for today's scotch ale brew day and use a .038 setting... Any comments on the crush? Good, bad?

 

[stpug]

.038 should be good but that looks like a pretty fine crush there; but maybe the picture doesn't do it justice. That might be almost too fine for my system (MLT with false bottom). But it wouldn't stop me from using it . I say roll with it and see if you have a stuck sparge. If not, and you get your efficiency, then you should be good.

If you're BIAB then that's probably perfect.

 

[jbaysurfer]

It does look a bit fine, finer then my .038 setting (I have the 2 roller MM), but it might work for ya, it does look like a lot of the husks are intact....anyway, they're crushed, may as well brew and see how it goes. If you have any rice hulls, I'd keep them handy in case you end up with a stuck mash....you can stir in the rice hulls and finish it out.

 

[jmark]

Thanks for the insight... Just got done with the sparge without any issues although my preboil gravity still came in 8 points lower (1.046) than it should (1.054) and that was assuming a 75% efficiency. Very frustrating. Had no issue collecting enough wort and the final runnings were in the high teens. Not sure what I'm missing - I built a Kal clone and have never gotten better than 70% which doesn't jive at all with what others are hitting on the same equipment

 

[mux]

Thanks for the insight... Just got done with the sparge without any issues although my preboil gravity still came in 8 points lower (1.046) than it should (1.054) and that was assuming a 75% efficiency. Very frustrating. Had no issue collecting enough wort and the final runnings were in the high teens. Not sure what I'm missing - I built a Kal clone and have never gotten better than 70% which doesn't jive at all with what others are hitting on the same equipment

Adjust with dme.

 

[jmark]

Gonna boil it down further than originally planned... Need to figure out why my efficiency is relatively crappy when compared to Kal's 90%+... I don't really care about hitting a high number... Just consistency.

 

[stpug]

Thanks for the insight... Just got done with the sparge without any issues although my preboil gravity still came in 8 points lower (1.046) than it should (1.054) and that was assuming a 75% efficiency. Very frustrating. Had no issue collecting enough wort and the final runnings were in the high teens. Not sure what I'm missing - I built a Kal clone and have never gotten better than 70% which doesn't jive at all with what others are hitting on the same equipment

From what I'm seeing, that's ~63% efficiency which is, imho, a far cry from your 75%. My opinion is that there's plenty of room for improvement.

As long as you're certain on your grain weight; the crush looked plenty good; then you're losing your efficiency somewhere in the mash/lauter process. I'll assume you're mashing is converting completely which would simply leave your lautering. Somewhere during the running(s) you're leaving a fair amount of sugar behind.

If you can explain your process of mashing and lautering then I'm sure folks will be happy to give plenty of suggestions.

I would personally like to know if you're batch or fly sparging? And, if batch sparging, how well you're stirring your initial mash prior to vorlauf and how well your stirring each subsequent batch sparge? I'm not familiar with "kal clone" so maybe these questions are irrelevant.

 

[jmark]

My grain weight is right on so I don't think that's the problem. I fly sparge (today took about an hour to collect 12 gallons) but I'm thinking that's this is exactly where things are going wrong (considering that my final runnings were still relatively high in gravity at 1.017) ... I don't stir at all during the mash or prior to sparging. I used to mash with a 1.25qt/lb ratio but this one I was closer to 1.6qt/lb which I thought would help, but no joy.

 

[acidrain]

Bazooka, manifold or FB?

 

[billl]

"I'll assume you're mashing is converting completely which would simply leave your lautering. "

That is not a safe assumption at all. The only way to know is to take measurements.

 

[jmark]

Blichmann FB... Mash converted fully (mash temp was 155 measured by both PID and thermopen)- did iodine test at 45 and passed... Let mash continue anyway for another 15 and then raised to mashout at 168 (took about 30 mins to reach/maintain 168 ) PH of mash was 5.4 (measured 10 mins after doughing in)

 

[billl]

An iodine test does not test for full conversion. All it does it look for starch in suspension. You need to take a gravity measurement and compare it to 100% conversion. I've tested and my mash "passes" the iodine test once I get to about 75% conversion. Braukaiser did a great writeup on the math and includes a chart for a mostly base malt beer. If you've got a ton of specialty malts, you'll have to plug the values in one of the formulas.


http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency#Measuing_conversion_efficiency

 

[Paloaf]

If you do end up with 70% efficiency, what's wrong with that? You might spend an extra dollar or two in base malt but you will be consistently hitting your numbers.

 

[stpug]

Based on my understanding, the OP's best efficiency has been 70%. This particular batch was closer to 63%. And, as they mentioned, they'd be okay with lower efficiency if there was consistency - which there is not.

And, IMO, if I were to spend what I assume to be LOTS of money building a Kal clone then I would want a solid, decent, consistent efficiency (75% or better). But that's aside the point

 

[jmark]

Yeah - consistency is more important although it would also be nice to hit a reasonable number given the investment of time and money I put into the system. Even if I could hit 70% EVERY time I'd be a happy camper (obviously taking into account the adjustments for HG brews)... There's obviously something I'm just missing... Next time I'll stir more during the mash and before lautering I guess along with mashing for 90 minutes.

 

[stpug]

jmark, I'm a batch sparger and have never fly sparged, so my comments should be taken with that in mind.

I'm not certain how important a roll stirring plays in fly sparging; certainly not as much as in batch sparging. I assume that stirring the mash prior to sparging is still helpful, but NOT if you're using a recirculating system since you're essentially ruining the grainbed the recirculation has created. It would be nice if a fly sparger could give some insight into their process as it relates to your system.

When I think of posts from other fly sparge users, I seem to recall somewhere along the lines of 45-60 minutes to reach preboil volume, and that faster can cause channeling which leads to efficiency reduction. My recollection is that most of these were from ~5 gallon batches. So, to reach a (effectively) double-batch, would that mean twice as long fly sparging (90-120min)? I don't know. I believe Yooper will brew 10 gallon batches and will also fly sparge sometimes too. She would undoubtedly provide some good feedback on your situation. Shoot her a PM; she's super helpful and very knowledgeable.

 

[jmark]

That's a really good point - the grain bed is set really well with the recirculation so stirring is probably not the solution. When I say fly sparging, what I'm really doing is matching flow rates into the BK and on top of the mash. I typically make sure there's an inch or two of water above the grain bed at all times and usually drain at a rate of 5 mins or so per gallon collected. I will experiment with a longer mash next time and see if that helps... I'm pretty sure it's not the crush, so we'll just remove one variable at a time until we find out the culprit. I appreciate everyone's thoughts and I may well have to consult the great Yooper!

 

[jmark]

Okay... This is a stale thread I started but in the interest of closing out the issue with a resolution, I figured i would post my findings. It was the crush... Secondly, it was the crush... And finally it was the crush!

Turned out the rollers on my mill were not aligned properly so some grains weren't getting crushed at all and some were just fine... It was hard to tell looking at the full bucket of crushed grain, but when I built a new stand for the mill, I noticed it and fixed it. Now my efficiency is quite a bit north of 90%! So, as seems to be the common refrain... struggling with efficiency... check your crush!


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[LandoLincoln]

Okay... This is a stale thread I started but in the interest of closing out the issue with a resolution, I figured i would post my findings. It was the crush... Secondly, it was the crush... And finally it was the crush!

Turned out the rollers on my mill were not aligned properly so some grains weren't getting crushed at all and some were just fine... It was hard to tell looking at the full bucket of crushed grain, but when I built a new stand for the mill, I noticed it and fixed it. Now my efficiency is quite a bit north of 90%! So, as seems to be the common refrain... struggling with efficiency... check your crush!

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So one end of the rollers were farther apart than the other end? Is that what you mean by misaligned?

 

[jmark]

In essence, yes. On my old mill stand one of the holes for attaching the mill to the stand was off line so the ends of the mill were not quite parallel which was causing there to be a bigger gap on one end. Built a new stand and the problem went away.


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[Lithobid]

So Jmark, as a newbie brewer what are your current crush settings, and some new pics please!! 90% is amazing! Are you doing BIAB?

 

[jbaysurfer]

Jmark,

thanks for the followup. Too often these threads are abandoned and then the next brewer doing a search will show up, read it, and have no idea what the solution is. Kudos!

Litho, don't worry about how high the efficiency number is, just as long as you can get it consistent. Many BIAB brewers are doing really low gaps in their mill, but I do a .038 gap for my 3 vessel batch sparge system and I can consistently hit my numbers at 80%, with larger grain bills being a bit lower then that.

 

[jmark]

I built a Kal clone which is a HERMS. My crush is set at .038 - I think the, now great, crush combined with the constant recirculation and a good false bottom has been the key. However, if my efficiency was 75% I'd be fine with that too - like jbaysurfer said - consistency is more important and the fact was I just wasn't getting it before I figured my problem out.


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