Recirc Mash Dramas

[Filby]

After many years of BIAB Ive moved to a 3V setup. Spent the last couple of weeks building it and got it up and running yesterday and have done 3 brews on it, all with the same issue.

Basically, I have a HERMS setup and when I recirc (which I do from the start of the mash) the wort never runs clear and also the bed compacts and pulls away from the side of the tun and the slab of grain is so hard it lifts as one piece. Im also getting average efficiency

Things I have tried:

• A 200mm false bottom and also a 300mm one.
• Slowing the flow to less than 1/2lt a minute (a dribble)
• Putting alfoil on top of the liquid to stop channeling
• Removing the sparge 'arm' and just using the tube end

Im starting to run out of ideas but have heard of using a grant and gravity flow into it to alleviate the pump vacuuming the grain bed down onto the falsey (dont see why I should have to add more crap to the system).
I also read on here that calcium makes a 'big' difference to mash fluidity. Anyone know any more about this?

Any help appreciated.

Cheers

Fil

 

[Ducatiboy stu]

Your false bottom/pickup is to small.

Try to get a false bottom and pick-up that is the diameter of your kettle.

Bigger the better

 

[razz]

Hi Fil. I think one problem is the silicon hose, it is most likely compressing and restricting flow. Also as Ducatiboy Stu says use the larger false bottom.
You didn't mention your mash in temp, trying to recirc to early at a low temp won't help things. Give the mash 5-10 mins to become fully hydrated before you recirc.

 

[macca05]

Im only an amateur ag brewer myself but do rice husks help with this problem too

 

[Ducatiboy stu]

No...not really.

Rice hulls are used when using lots of rye and other grains that make your head explode when trying to sparge.

Its also not illegal to give your mash a stir when sparging

 

[Yob]

How fine is your crush? Too much flour can add to woes and a set mash.. Your standard BIAB crush can be too fine for a 3V system..

Just a thought

 

[Filby]

Ive also got a 300mm FB that takes up the full diameter of the tun and that made no difference. I dont have a problem with flow as such, more the compaction of the grain bed, when that occurs the grain bed pulls away from the side of the tun and the wort bypasses the grain bed.


Cheers

Fil

 

[Filby]

Crush is standard beerbelly crush that they use for all their sales so I assume its suited to 3v as well as biab.

 

[macca05]

No...not really.
Rice hulls are used when using lots of rye and other grains that make your head explode when trying to sparge.
Its also not illegal to give your mash a stir when sparging

Was worth a try. My LHBS guy uses the rice hulls in all his brews. Thats why i thought it helped with stuck sparges

 

[Ducatiboy stu]

Ok...

So how long does it take to empty the tun if you let it drain into a bucket

 

[Yob]

That third photo sure does look like set flour.. Do you start the recirculation slow?

 

[Filby]

No idea. The flow rates under gravity seem fine as far as I can tell.

 

[Filby]

Um I try to start it slow but to get the pump primed and running i open it up but only for 15-20sec then back it right down. Also, the grain gets a greyish film/slime over the top once I can see after sparging.

 

[Filby]

I do start recirc straight after mashing in and dont let it settle..i didnt know you need to. Also mash temp is 66deg and i mash in at that temp (72deg strike water).

Ive tried stirring it back up again multiple times but the bed must just compact and I get channeling down the sides and hence the bed never acts like a filter.

 

[Yob]

If you stir it the grain no longer acts as a filter and all the fine particulate gets pulled to the bottom and can clog.

I also start recirculation right away.. No need to stir if you have recirculation. I do have a bit of a hybrid sort of a system though and initially liked to stir too, had a similar issue once or twice, stopped stiring and havnt had the issue since.

 

[Filby]

I only stir once it gets compacted and there's no flow, but shortly afterwards it compacts again.

 

[vortex]

Was worth a try. My LHBS guy uses the rice hulls in all his brews. Thats why i thought it helped with stuck sparges

It does. Just so happens Rye and Wheat often cause stuck sparges which is what the rice hulls help with. There is no reason why they can't be used in all-barley mash if you're having sparge issues.

 

[vortex]

I only stir once it gets compacted and there's no flow, but shortly afterwards it compacts again.

Really sounds like the pump is compressing the grainbed - also as mentioned previously the silicon hose is probably collapsing. BeerBelly sell a reinforced hose which resists collapsing. I've never had these issues with that hose - I'd suggest you try some of that also.

 

[Filby]

I will replace the hose out of sheer hope that it fixes the problem . What I am interested in was why would a collapsed hose cause compaction as the vacuum under the grain bed would effectively stop when the hose collapses?


Fil

 

[Camo6]

Are you opening your tap to quickly to start with? This will cause that sort of issue as the grain bed settles too quickly. Try cracking it a bee's dick to start with. I've got a tap teed in near my pump inlet to help with priming the pump and giving that initial flow somewhere to go.