National Homebrew Club Ireland

Today I brewed a NEIPA. It's my second time brewing this recipe. However, this time my og was 1020 instead of 1069.

Two differences from the last time were that I crushed the grains myself. First time using the bulldog mill. Set the width so that a credit card can just squeeze through.

The other difference is that I have a new larger brew pot.

The recipe was:
6kg Pale malt
920g Vienna
750g Oats
500g Oat Hulls

Mashed at 65 degrees for 60 mins. Boiled for 60 mins.

For the mash water I used a ratio of 2.5L/kg. I included the weight of the oats in this but not the hulls (is this normal?). So this was 2.5 x 7.67= 19.2L. I mashed out with 4L of watered at 80 degrees and batch sparged with 16. I added 2 litres of water to bring my pre boil volume up to my desired 30L.

I boiled more vigorously than usual because of the bigger pot. Boil off total was 4.5L approx.

Added 24L to the fermentor before pouring down the drain.

I noticed that the mash was thinner than usual. I used 41L of water in total, when I brewed this the last time I used 37L, but my boil was more vigorous today. Even if wasn't more vigorous surely that 4L cant cause this huge loss.

After that I guess it's either the crush or my scales. The scales should be ok but I will double check.

300g of hops died today and I am feeling rather stupid so any help would be great.

Thanks.

What temp was the wort in the fermenter when you took the oh reading?

Check your hydrometer in water. Doesn't sound right at all, even with the worst crush possible.

Temperature was down to 20 degrees when I took it. Will check the hydrometers but it's unlikely that both of them are off equally. Just checked my scales with a commercial at work incase it was drastically off but it's not.

Ok just ferment out that one don't bother dry hopping and go again.
Any spare grain you could crush a handful and post a pic?

I just spilled it down the sink at the time. Didn't think there was any point in wasting the yeast.

I just checked my hydrometers in water and they are fine.

I will crush some grain tomorrow and post a picture.

Thanks

I assume that's before crushing?

Unfortunately not. Just set it with  the credit card and never really looked at it tbh before mashing. Mystery solved

Quote from: Pheeel on March 05, 2017, 09:44:47 PM
I assume that's before crushing?

Did I miss something?

Quote from: CH on March 05, 2017, 10:05:23 PM

Quote from: Pheeel on March 05, 2017, 09:44:47 PM
I assume that's before crushing?

Did I miss something?

I think he means that he either forgot to crush the grain or else the grain actually passed through without getting crushed.

Shanna

Sorry, I deleted the pic trying to edit. Please don't laugh . Obviously the credit card setting isn't universal.

(https://uploads.tapatalk-cdn.com/20170305/e0fbbf22dc9463951ed02aea0c1953dd.jpg)

Ok what you are looking for is every grain crushed and popped out of kernel. If it's shredded to fines or you have too much flour it's too much.
The Kernals will stop you getting stuck Mash

No worries! You must have a thick credit card!! The grains aren't even cracked

Well that was the setting Pheel.

Thanks CH

You can get gauge measurers that are a bit more accurate for width. Halfords (or an equivalent) should we have them

Cheers, will get one of those. Time to experiment a bit now and get over my silly error.

It will take a brew or 2 to get it 100%

Quote from: CH on March 05, 2017, 10:36:33 PM
Ok what you are looking for is every grain crushed and popped out of kernel. If it's shredded to fines or you have too much flour it's too much.
The Kernals will stop you getting stuck Mash

It's worth noting that if you use too strong a power setting you can end up without the grain getting crushed. You want high torque with low speed to crush the grain between the rollers. I follow the trick of adding 2% by weight of grain in water via a spray bottle to the grain before crushing e.g. 5kg of grain  = 100 ml of water . I leave it sit for 20 minutes & then crush. This gives a nice even crush with less flour.

Shanna

What type of mill are you using? I have a bulldog that i use with the credit card gap and get a lovely crush.

Quote from: BigDanny84 on March 05, 2017, 11:02:26 PM
Cheers, will get one of those. Time to experiment a bit now and get over my silly error.

Don't consider any error "silly", rather take any opportunity to learn a new lesson and become a better brewer :)

Another thing that could have saved the day is early detection of the inconsistency:
- did you taste the entire and crushed grains? They should *feel* different
- did you measure the gravity before boil? It's useful to understand how your efficiency "builds up" (and you easily detect conversion issues)
- did you taste the wort at the beginning and at the end of the mash? It should be very grainy initially, very sweet at the end
- did you perform a iodine test to check conversion of the starches? Seems a very advanced technique but it's rather simple...

Buy a 500g of crushed grain (costs about a euro) so that you'll know what properly crushed grain should look like

Quote from: armedcor on March 06, 2017, 01:30:55 AM
What type of mill are you using? I have a bulldog that i use with the credit card gap and get a lovely crush.

Ya it's a bulldog that I have too. Perhaps the speed I used was too high like Shanna suggested.

Thanks for all the suggestions.

Here's my two hapence worth, a few times I got distracted while weighing grains, I was using a kitchen Scales with a maximum load of 1.5kg so it involved a few batches. It's easy to forget have you measured 5 or 6 kg, I'm a bit ocd like that so ended up weighing twice a couple of times. I've since bought a proper 30kg scales, so no more messing around. I bought the same one as Ian uses in Motley Brew, great value. I had to use parcel motel as they don't deliver to Ireland
https://www.amazon.co.uk/dp/B0047ML82G/ref=pe_385721_37038051_TE_3p_dp_1
The second point is in adjusting the roller gap on your mill, there are the adjusters on both ends plus locking screws, make sure that the locking screws are secure after adjusting or the rollers will separate themselves in use.
Here's a nice little guide on measuring and adjusting mill rollers, you'll have to scroll down the page to get the relevent section
http://www.homebrewengineer.com/category/how-to/

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Thanks Sorcerers Apprentice. I def didn't check the locking screws after adjusting. Bigger scales is a good idea too. Will check out that guide too.

So I got a measuring gauge. Adjusted the rollers and tightened every other screw fully and have had more or less the same result. The last setting I used was 0.13mm and this was the result. Starting to think that the mill is faulty or I'm faulty .(https://uploads.tapatalk-cdn.com/20170306/660a0d6382ab0d1200a2630ca1fd74b0.jpg)

Are you sure the screws are staying put? If you have it tight and its not crushing it must be getting wider as you try to push the grain through.

Ya the screws are staying 100% put. Perhaps these gaps are causing it. It was like this when it came. (https://uploads.tapatalk-cdn.com/20170306/50f2a69c09307d8806ff207fd2209140.jpg)(https://uploads.tapatalk-cdn.com/20170306/a509f311bfaf2d92e41296cfee1f8b6e.jpg)

bite some of that grain. is it soft or crunchy?

It's very crunchy.

Without damaging them can you put a screwdriver in and is there play in the rollers? They should be solid
0.13 doesn't make sense, gap should be circa 0.9-1.1mm
Can you post a pic of gap with a grain or two?

Rollers are solid but only one of them moves.

Other should rotate if pushed?
It might be stiff but that's ok

Both should move. They're geared.

The other one moves with a bit of force from underneath.

Change the gap and took the pic u requested CH
(https://uploads.tapatalk-cdn.com/20170306/23257bc296c2ce0036895e6001b3bb17.jpg)

And that gap gives you what's on the plate?

The same as the above

Go narrower and crush again and take a pic

Will do tomorrow, thanks.

Is it possible that you turned the handle the wrong way when running the grain through the mill and instead of the two rollers going inwards, they were both rolling outwards and not crushing the grain I.e. The grain was just getting thrown over the side?

That is possible but when I turn it the other way the rollers are stationary and no grain exits the mill.

I love an Agatha Christie, they are the most fun to solve

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There is a pic of the guide screws on my bulldog mill. I'm having no problems with it so far. I also calibrated with a credit card and I've had perfect crushes everytime. I did notice that sometimes the drill losses it's grip on the mill if it's not tightened enough.

Quote from: BigDanny84 on March 06, 2017, 10:01:49 PM
That is possible but when I turn it the other way the rollers are stationary and no grain exits the mill.

This sounds like the issue to me. They are meant to be quite hard to turn, so I'd say your going in the opposite direction and the grain is just going over the sides and not getting crushed.

Alternatively maybe the gearing mechanical is jammed. Thought you couldn't move one of the rollers in isolation though, as they are linked by tye gearing system.

There is a max speed for crushing grain, those bulldogs are further complicated in that they have plastic interlocking gears so have the potential to shred teeth if operated too fast.

Tips for milling alway start your drill on slow speed, feed into spinning drums and use a clamp to have a continuous speed

Thanks lads, will consider all this. I have tried to use the mill without the drill and was having the same results.

Can you make a video of whats going on? I got the same mill recently and have had no issues with it. Calibrated to credit(debit!) card size and it cracks them perfectly.

Like all rotating/moving equipment!!! DO NOT RUN it again until you understand why it bound up you will only make it worse.   

If the Rollers do not roll free I would suggest a complete strip and clean down to understand why! Take every thing apart that can come apart  and see where the binding is. We all put drills on them but they are not designed for it . I had a problem with mine not a Bulldog type mine was an M3. Basically when running in the correct direction to mill grain, the threaded shaft from drill to drive roller would start to unscrew itself from the Knurled roller and bind on the Mill housing jamming the mill. Your symptoms sound very familiar to mine and I note rotational  score marks on the Mill drive shaft in one of your pictures Mine ate a bearing in the process..... skate board bearings are the correct size to replace!!

My fix was rebuild and to flip to whole Mill so that the drill and mill rotation tightened the drive shaft to Knurled roller when load came on and did require re-drilling some holes to mount the mill and Hopper....  Hope this helps. 

Expose the gear housing, and check if your gears are intact.

Quote from: Damien M on March 07, 2017, 12:03:03 PM
Like all rotating/moving equipment!!! DO NOT RUN it again until you understand why it bound up you will only make it worse.   

If the Rollers do not roll free I would suggest a complete strip and clean down to understand why! Take every thing apart that can come apart  and see where the binding is. We all put drills on them but they are not designed for it . I had a problem with mine not a Bulldog type mine was an M3. Basically when running in the correct direction to mill grain, the threaded shaft from drill to drive roller would start to unscrew itself from the Knurled roller and bind on the Mill housing jamming the mill. Your symptoms sound very familiar to mine and I note rotational  score marks on the Mill drive shaft in one of your pictures Mine ate a bearing in the process..... skate board bearings are the correct size to replace!!

My fix was rebuild and to flip to whole Mill so that the drill and mill rotation tightened the drive shaft to Knurled roller when load came on and did require re-drilling some holes to mount the mill and Hopper....  Hope this helps.

The bulldog comes with a special attachment for drills so that would be a big problem if it really wasn't designed to be used by a drill.

So I did what Damian suggested at the weekend and I took everything apart, cleaned the rollers with a brush, put it all back together and reset the gap and it worked.

Initially it only worked manually (took a bit of effort) but it would not turn with the drill. I presume this is what was happening the first time around and when it wouldn't turn clockwise I presumed it had to go the other way. So well diagnosed Molc. After fiddling with the drill settings it worked fine.

So I rebrewed my NEIPA on Saturday and hit my numbers. Thanks to everyone for the friendly advice. It was a good lesson for me and I'll never again be as naive to think once grain comes out of a mill at the correct gap that it is actually crushed.

Thanks guys!

This is what I love about the NHC, a problem shared and solved.

http://www.soundcloud.com/aural-abuse

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