BB Ale malt - inconsistent size grains?

[thermo_47]

Hi all,

I've been using Barrett Burston Ale malt for a while now as my base malt and having a few dramas with my mill in terms of speed vs crush size. I'm finding that some whole grains are coming through seemingly uncracked if I have the gap at a reasonable width (so that it doesn't take an hour and 20 mins to mill 15kg of grain!) Finer gap, it cracks them, but with a lot of flour and it takes a LONG time.

Here are the variables:

• Using a Millmaster MiniMill with the perspex hopper from Ross
• I don't have feeler gauges so I don't know the exact gap, but would be approx 1-2mm (I'll buy some gauges and cop a feel, then get back to you)
• Driving the mill with the Bunnings Mixer Drill as oft discussed around here (I think it's this one but mine's an older model)
• I've tried the drill slower and faster (having read that about 250 rpm was ideal) and it's even slower to crush there, so I run it full bore.
• I am aware that grains can be crushed sufficiently and look "whole" - I'm talking about grains that are definitely not cracked when you press them between your fingers etc.

Now what drives my thinking is that when I use Weyermann malts etc, the crush size seems to be more uniform. It also seems to flow a bit quicker through the mill. I feel like I can see the inconsistency in the grains sizes from a handful of BB compared to other brands, but I'm at work right now with no photos to backup my story.

Anyone else experienced this? Or could shed some light on the subject? I'm sick of waiting around for an hour to crush grain. It's almost like I just need more down-pressure to push the grain through - bigger hopper perhaps?

I also find that if I put my hand in the hopper and press the grain down, it flies through the rollers much faster. I was doing this until the mill bit my finger. Not recommended. Lucky I still have a hand and that lovely powerful drill torque didn't pull me through those wonderfully geared rollers! However, it seems the 2 issues are both the rollers not grabbing the grain as easily as when I push down on them, and also the smaller sized grains from BB falling through without getting crushed.

I like the "local" factor, flavour and price of BB, so maybe if there's an issue with my setup that would allow the finer crush to happen in a reasonable amount of time, I could just compensate for that in the mash with rice hulls or something. Any help?

 

[syl]

Can't shed much light on BB malts, haven't used them myself. But I can say, you really need to get a gauge of the exact gap. The difference between 1mm and 2mm is huge!

I am sure people here or Ross can tell you what the marks are roughly.

One of the thing I have had with issues like this was one of the sides slipping a little during the milling process.

 

[warra48]

Do you have the mill running before you feed it your grains?

If so, some of the first feed into the rollers can bounce around over the top of the rollers, and miss being milled. This is especially the case if you have your drill driving the rollers at full speed.

Slowing down will help. You just need to find the sweet spot for speed and crush.

I'd also get yourself to a hardware store and get yourself a set of feeler gauges. Just a couple of bucks, and you have total accuracy in your gap.

 

[bradsbrew]

I have the same mill but a home made, well not home made some apprentices made it for me, hopper. I use a lot of BB malts and don't have the same issue, although I do run it slightly quicker than recommended. I have it set to a width that allows a credit card to just fall through. I can get through 12kg in around 5 minutes, will time it next time. I get around 82% eff. The original set up was a bit of a PITA, I basically threw in a hand full ran it through, checked the crush, adjusted etc.
Is the gap consistent across the width of the mill?

 

[QldKev]

As above, stop stuffing around. Get some feeler gauges, and get a consistent speed. I use BB all the time and never have had an issue. Also I use a motor on the mill and crush for a 112L batch, time is not an issue with a decent setup.

http://www.youtube.com/watch?v=lS3axZtOYu4

In this video I crush 5.5kg @ 160rpm in 2min 20secs using an 0.9mm gap.

Yes my hopper is pretty basic. 1.5kg of grain on top in the hopper was already crushed, I just threw it back in to get the volume up a bit for the test.

 

[bradsbrew]

As above, stop stuffing around. Get some feeler gauges, and get a consistent speed. I use BB all the time and never have had an issue. Also I use a motor on the mill and crush for a 112L batch, time is not an issue with a decent setup.

What gap do you have yours set to Kev?

 

[QldKev]

What gap do you have yours set to Kev?

I edited it after I had posted, I use a 0.9mm for both my 1V and my 3V.

 

[bradsbrew]

For some reason the video doesn't work on the iPad Kev.

 

[adryargument]

In this video I crush 5.5kg @ 160rpm in 2min 20secs using an 0.9mm gap.

As above, i use the motion dynamics motor that is supposed to be around 180RPM = perfect crush.
By my estimate i get about 140ish which takes a bit longer. I start crushing and go setup the brewery leaving the mill on, once its empty it spins until i get back and have time to brush the last stranded grains through and switch her off. 15KG probably takes me between 10-15 minutes by estimate. Never measured but it feels like ages when im watching it, and is done in minutes while occupied.

However i tend to get a semi decent crush, with quite a bit of flower and also a few uncracked grains that seem to 'overflow' the hopper and around the sides. Keep in mind i use a sideless hopper i built myself as its so easy to clean with a few swipes of a paintbrush.

I use a commbank debit card as a spacer and the width is around 0.9 if i remember correctly.

One of the more important aspects i find is to end up with halved barley shells, as these are the filter bed that keeps the flour from blocking the dotted thing with lots of holes.... (mindblank??). With the above settings i generally get quite a bit of flour, halved shells, and barley that is broken down into a range of halves, thirds and quarters. Lots of generally bits and pieces of cracked barley.

By all means my crush is not 'uniform' by a looong way. But it gets the job done and at the end of the day the other 50% of getting a decent efficiency / most out of your grain is how you learn to user your equipment with your crush size. I have my pump on slightly slower than i woul;d like, but this allows me to keep the bed fairly uncompacted and allows the liquid to recirculate better then having the pump faster, qwqhich simply causes clogs. Sometimes less is more.

Edit: Warning - spelling mistakes above, cbf'ed fixing them.

 

[pk.sax]

1. set gap to just about a credit card width

2. load hopper up

3. turn speed down all the way, turn it on, push in the speed lock.

4. Dial up the speed dial till it starts milling and keeps milling.

You might be milling too fast and having the grain slip. Also, if the grain is not that uniform, and the gap is too big, the grain might be just slipping through the gap instead of being pulled through. Probably the fact you've got a geared mill is saving you fro mno crush.

I use a very basic hopper - a 4L bottle of water with the bottom cut out of it. The same drill as you and an ungeared mill. No problem milling.

 

[thermo_47]

Yeah cheers all. I'm definitely getting nowhere near the 10-15 mins mark. I bought some feeler gauges last night so I'll set it to 0.9mm gap as suggested and wind my drill speed up til we're crushing and see how the speed is.

I used to have a cheaper malt mill without geared rollers (very much like the keg king ones, but unbranded) and it was heaps faster. I upgraded to the geared millmaster to avoid this!

Out of interest I'll measure the gap I currently have - if practicalfool reckons that:

the gap is too big, the grain might be just slipping through the gap instead of being pulled through. Probably the fact you've got a geared mill is saving you from no crush.

then perhaps this is the case. I wouldn't have thought that a gap TOO big would mean little crushing - but the opposite. I'll report back with pictures tonight.

 

[thermo_47]

FWIW I found a pic I took last time I was crushing grains... does this look right?

Seems too coarse to me.

 

[QldKev]

Looks pretty close, but there does appear to be a few un-split husks. I would reduce it 0.1mm

 

[stakka82]

Often the husks look unsplit but when touched are actually hollow.

My whole crush basically looks like that (so appears much coarser than above) but still consistently pull 80%.

As said previously I would be looking at speed and hence consistency of the crush.

 

[thermo_47]

Thanks Kev, I thought I was in the ballpark.

stakka, as I mentioned in the OP these are grains that I'm inspecting and trying to crush with my fingernails etc and are definitely not hollow or crushed by the rollers. They seem to be passing through untouched. I will have another look at the speed of my drill as a starting point for consistency. My efficiency has been around 75 usually without adjusting mash PH (which apparently can add a few points). I'm not super-concerned about efficiency if I'm taking tasty beer - more the time taken to mill those little suckers!

 

[pk.sax]

Yes, my guess is your hopper feeds straight into the mill, very little for the grain to sit on. The weight might be compacting the grain and holding it together making it slowly slip through the rollers rather than pull and crush. A smaller opening to the rollers actually lets the trickle be manageable and the grains spread out on the rollers for the crush anyway.

Still weird that it only happens with one brand of grain.

 

[pk.sax]

Yes, my guess is your hopper feeds straight into the mill, very little for the grain to sit on. The weight might be compacting the grain and holding it together making it slowly slip through the rollers rather than pull and crush. A smaller opening to the rollers actually lets the trickle be manageable and the grains spread out on the rollers for the crush anyway.

Still weird that it only happens with one brand of grain.

 

[thermo_47]

Well, I have some numbers. And there's definitely something wrong with my setup! No longer blaming BB ale malt...

My mill had been set at 1.25mm one side and 1.35mm on the other. I took this down to 0.9mm as others are doing and put 1kg of BB ale malt in the hopper, set my drill speed to the slowest setting and wound it up until grain started feeding through. 14 clicks, for reference. After 30 mins of milling grain, it was not finished. I switched it off and weighed the leftovers - I'd only crushed 448gm of grain. Doing the math, this equates to 14.93gm/min. The crush is real floury, but there's still whole grains in there! They must be escaping out the side of the hopper/at the ends of the rollers or something.

So I cranked my mill back up to 1.2mm. Another 1kg of BB Ale malt. Same slow-as-possible drill speed (this time 12 clicks). Takes 22 mins 42 secs, which equates to 43.95gm/min. Better time, but that's gonna take me 5.68 hours to crush my 15kg, which I know it doesn't normally, but remember that normally I'm there pressing down on my grains with my hands, which makes it fly though.

Slightly frustated, I put 1kg of Weyermann pilsner malt in at 1.2mm gap, and crank the drill up to max. By this stage, I just wanna know if BB Ale Malt is the culprit, or the mill setup itself. We chew through that in about 6 mins flat, which is 166gm/min. I'd still have to compare Weyermann and BB at high speed to get an idea of the difference, but this is still waaaaaaaayyy off QLDKev's 5.5kg in 2min 20sec, which is 2391.3gm/min.

SO what's going on?! :/

I've attached a few photos for reference and have some video footage which I'll throw together and chuck on here which may help solve the problem...

 

[bradsbrew]

How quick does the grain go through if you put the drill in reverse? Can you do a pic of the hopper empty, it's got to be the hopper?

 

[QldKev]

How quick does the grain go through if you put the drill in reverse? Can you do a pic of the hopper empty, it's got to be the hopper?

Looking at the position of the direction lever on the drill, I think the rollers are running in reverse