GF and grain crush

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johnluc
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GF and grain crush

Post by johnluc » Wed Feb 08, 2017 1:15 pm

Hi all, a question for GF owners, bought a 3 roller malt mill and did my first crush at 1.1ml gap, all through the sparge it was just cascading down the overflow tube for the whole duration of mash, at end of sparge the top plate was about 2" above the grain bed and covered in flour, ended up very cloudy and very fine particles in fermenter, 2nd brew i crushed at 1.2ml gap and got the same results all be it not quite as bad. have had my GF for over a year now and never had this before using pre crushed. any thoughts?

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Re: GF and grain crush

Post by BrannigansLove » Wed Feb 08, 2017 3:29 pm

Maybe call the shop you got your pre-crushed grain from, and ask them what setting they use.

shepp

Re: GF and grain crush

Post by shepp » Wed Feb 08, 2017 4:08 pm

I have had the same problem.
My first brew was with a Brupaks kit and the wort flowed through great.
I then bought 4 kits from a supplier and the first two have been terrible, they are only 12 litre batches too :(
I have had to dig onto and turn over the grain bed to make it possible to sparge, so my wort is of course very cloudy.
I wondered if adding rice husks to my remaining two might help flow?

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Re: GF and grain crush

Post by johnluc » Wed Feb 08, 2017 5:24 pm

Thanks for replies, i thought about asking supplier about crush size and will do that, i've not used rice hulls but i know a lot of brewers do use them but i would rather get my crush right. it can only be that as i've done about 14 brews using pre crushed and never had a problem before.

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k1100t
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Re: GF and grain crush

Post by k1100t » Wed Feb 08, 2017 5:35 pm

After a couple of stuck mashes when I started out, I now always use Oat Husks, wouldn't brew without them...

Cheers,

Bob.
I like beer --- Currently rebuilding the brewery, this time with stainless...

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Re: GF and grain crush

Post by BrannigansLove » Wed Feb 08, 2017 7:01 pm

I use a 0.9mm crush on my bulldog mill, but I condition my malt before it's crushed. I tend to adjust the flow of the recirculation to minimise the overflow, and use a steel mesh plughole strainer to prevent grain particles going down the overflow pipe.

johnluc
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Re: GF and grain crush

Post by johnluc » Wed Feb 08, 2017 7:41 pm

Have emailed supplier so hopefully will get an answer for crush size, what i can't understand is why my grain bed compacted so much to end up at least 2" below top plate on both mashes even though i cut right back on pump flow for second one, also on both, the crush and spent grains didn't look much different to all my previous brews.
ps when you say condition your grain, do you mean dampen them before crushing.

shepp

Re: GF and grain crush

Post by shepp » Wed Feb 08, 2017 11:32 pm

k1100t wrote:After a couple of stuck mashes when I started out, I now always use Oat Husks, wouldn't brew without them...

Cheers,

Bob.
Can I please ask you at what ratio you use?

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Re: GF and grain crush

Post by k1100t » Thu Feb 09, 2017 12:24 am

shepp wrote:
k1100t wrote:After a couple of stuck mashes when I started out, I now always use Oat Husks, wouldn't brew without them...
Can I please ask you at what ratio you use?
I think I started out with about 200g in a batch, then went up to 250g. Having checked my notes, which are a bit patchy on the subject, the last two brews got 333g each. One of those was a 4.5KG mash, the other a 5.35KG mash. I haven't had any issues with using that amount, although I'd probably use more if I was using more grain.

Cheers,

Bob.
I like beer --- Currently rebuilding the brewery, this time with stainless...

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IPA
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Re: GF and grain crush

Post by IPA » Thu Feb 09, 2017 9:09 am

johnluc wrote:Hi all, a question for GF owners, bought a 3 roller malt mill and did my first crush at 1.1ml gap, all through the sparge it was just cascading down the overflow tube for the whole duration of mash, at end of sparge the top plate was about 2" above the grain bed and covered in flour, ended up very cloudy and very fine particles in fermenter, 2nd brew i crushed at 1.2ml gap and got the same results all be it not quite as bad. have had my GF for over a year now and never had this before using pre crushed. any thoughts?
What did the crushed malt look like? Can you post a photo? I use a Schmidling two roller mill set at 1.2 mm and it works fine in my BM. Having said that it is finer than the ready crushed that I once bought from the same supplier as you. MM ? But conversely my efficiency with the ready crushed was way below that which I achieve with my own crush. I have also noticed that different makes of malt are sometimes very different when crushed at the same setting. That is to say one will have a higher percentage of flour than the other. Probably due to the moisture content. And it is this flour that is causing your problem. Try crushing small samples at different settings and then choose the one that looks the best ie the one that has ruptured the grain without creating flour. The commercial crusher that your supplier uses is different so there is no point in asking him for a roller setting. I know because I have already asked him that question. One more thought were there any flaked cereals in the mash when you had this problem?
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johnluc
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Re: GF and grain crush

Post by johnluc » Thu Feb 09, 2017 10:06 am

IPA wrote:
johnluc wrote:Hi all, a question for GF owners, bought a 3 roller malt mill and did my first crush at 1.1ml gap, all through the sparge it was just cascading down the overflow tube for the whole duration of mash, at end of sparge the top plate was about 2" above the grain bed and covered in flour, ended up very cloudy and very fine particles in fermenter, 2nd brew i crushed at 1.2ml gap and got the same results all be it not quite as bad. have had my GF for over a year now and never had this before using pre crushed. any thoughts?
What did the crushed malt look like? Can you post a photo? I use a Schmidling two roller mill set at 1.2 mm and it works fine in my BM. Having said that it is finer than the ready crushed that I once bought from the same supplier as you. MM ? But conversely my efficiency with the ready crushed was way below that which I achieve with my own crush. I have also noticed that different makes of malt are sometimes very different when crushed at the same setting. That is to say one will have a higher percentage of flour than the other. Probably due to the moisture content. And it is this flour that is causing your problem. Try crushing small samples at different settings and then choose the one that looks the best ie the one that has ruptured the grain without creating flour. The commercial crusher that your supplier uses is different so there is no point in asking him for a roller setting. I know because I have already asked him that question. One more thought were there any flaked cereals in the mash when you had this problem?
the crush looked ok to me, no obvious difference to ready crushed, will take photo when i next crush, and no there was no flaked cereals, 1st was 3.8Kilo MO and 80g of roasted barley, the 2nd was 4.6k MO and 33g of black malt, having said that both beers have turned out very good and are now crystal clear after finning with gelatine, but when things don't go as expected and you end up putting 5gal of cloudy almost muddy wort into fermenter i get a bit pee'd off.
ps, i've read that some people "condition" their grain before crushing, is that wetting the grain prior to crushing ? and also having the rollers moving before adding grain ?

Rad

Re: GF and grain crush

Post by Rad » Thu Feb 16, 2017 2:28 pm

I use a 2 roller Bulldog mill set at 0.9mm. I do condition the grain and I've never had a problem with a stuck mash. For wheat beers I add about 200g of husks. Mash and sparge were slower without them but never stuck. It's really just convenience. The wort is meant to go down though the overflow pipe. That helps GF keep a constant temp. I leaned that the hard way. The key measure is your efficiency. If it's 70%+ you're ok. Just make sure that when you dough in, you mix it so all the hulls don't get pushed into on place.

As with any equipment change, you'll need to find out what works best.

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Re: GF and grain crush

Post by johnluc » Wed Mar 01, 2017 6:17 pm

johnluc wrote:Hi all, a question for GF owners, bought a 3 roller malt mill and did my first crush at 1.1ml gap, all through the sparge it was just cascading down the overflow tube for the whole duration of mash, at end of sparge the top plate was about 2" above the grain bed and covered in flour, ended up very cloudy and very fine particles in fermenter, 2nd brew i crushed at 1.2ml gap and got the same results all be it not quite as bad. have had my GF for over a year now and never had this before using pre crushed. any thoughts?
Hi all, strange day today, i conditioned my grains set my rollers at 1.0ml no more problem with bits of grain or cloudy wort, hit all my targets, "BUT" throughout the mash i had a substantial amount of foam on top, my grain bill was 3.4k MO, 210gm crystal and 100gm of black malt. any other GF users had this happen.?

Rad

Re: GF and grain crush

Post by Rad » Fri Mar 03, 2017 3:51 pm

Initial foaming is normal for me. Especially on wheat rich beers. It does go away after a couple of minutes of re-circulation.

johnluc
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Re: GF and grain crush

Post by johnluc » Fri Mar 03, 2017 5:03 pm

Rad wrote:Initial foaming is normal for me. Especially on wheat rich beers. It does go away after a couple of minutes of re-circulation.
No wheat used and it was foaming for the whole duration of mash and lots of it. had my GF for nearly 18 months now and never had foaming before.

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