Stuck Mash With Blichmann False Bottom

[SavoryChef]

So I upgraded to a 30 Blichmann mash tun, and am having problems with recirculating and stuck sparges with my pump. I am not going full bore with the pump speed. I have even voulauf with gravity and eventually it still sticks when I switch over to my pump.

I had my MM3 set at .39 and didn’t have any problem with my last mash tun. I opened the gap to .42 and still having problems even with some rice hulls. It seems the flour is clogging the gap and I’m getting some grains through and into my hoses. I’ve brewed 5 batched with this mash tun and it has happened every single time, even with it 25% or 75% full.

It seems the gaps in the false bottom aren’t wide enough. Any advice would help.

 

[TungstenBeer]

I have even voulauf with gravity and eventually it still sticks when I switch over to my pump.

Have you considered the pump as being the problem? Also, what water/grain ratio are you using?

I'm not trying to dismiss your diagnosis of the false bottom being the problem, but I've just never heard that issue with the Blichmann with that coarse of a crush.

 

[SavoryChef]

Yes I have considered my pump as a potential problem. But this whole thing just doesn't make sense. Even when I pump really slow. My recent brew was dough in at .9 qt/# then infusion up to 148 which brought it up to 1.7 qt/#.

 

[dfess1]

are you running your valve wide open on the pot? I run mine cracked, along with cracked on the pump as well. If it's wide open out of the pot, it will stick.

 

[SavoryChef]

Yes, the pot is wide open but the valve on the out on the pump is throttled. I will try that this weekend. I never thought of that. But it seams you would be restricting the inlet to the pump and it would cavitate

 

[day_trippr]

Be careful about throttling via the vessel valve, the pump is best throttled at its output...

Cheers!

 

[Wobbegong]

I use a Blichmann mash tun and never have a problem with sticking. I always set the kettle valve full open and use the valve after the pump to adjust the flow rate.

Are you recirculating too fast? Maybe try running your return into a measured container with a stop watch to determine your flow rate. Too fast maybe? I usually run at 1.5 gpm.

Do you have any street 90's in the flow path? I've seen them get clogged with grain..

Good luck, hope you find the problem.

 

[ArcaneXor]

The sight gauge on the Blichmann kettle serves as an indicator for imminent stuck lauters. If you see the liquid level in the sight glass dropping, reduce the flow until it stabilizes. At least it works this way on my 15g G1.

I would also try more rice hulls and step mashing rather than multiple infusion mashes. At 0.9 qts/lb, there is very little free liquid in the mash, meaning you are more likely to get stuck recirculations.

 

[kombat]

It's the pump. It's creating suction. The solution is to use a grant.

Drain the mash tun at a trickle into the grant using gravity. Use the pump to recirculate from the grant back to the mash tun. This allows you to continuously recirculate until the wort runs clear (instead of manually vorlaufing). It also gives you a convenient way to check the wort pH (i.e., check it in the grant). Finally, it allows you to avoid interrupting the flow of wort from the mash tun (as you would when stopping the pump, closing valves, switching from recirculating to draining to the boil kettle). That is, once you've started drawing runnings from the mash tun, the flow remains constant the entire time, right through to draining the last drop into your boil kettle. This avoids disturbing the grain bed, which can cause a stuck mash/sparge.

 

[TungstenBeer]

Yes I have considered my pump as a potential problem. But this whole thing just doesn't make sense. Even when I pump really slow. My recent brew was dough in at .9 qt/# then infusion up to 148 which brought it up to 1.7 qt/#.

Are you recirculating before your 148* infusion? That would almost certainly compact the grain bed enough to where you could have problems... regardless of what equipment you have.

 

[SavoryChef]

So I brewed again today with 45% wheat 45% Pilsner and 10% rice hulls-2# in a 10 gallon batch and recirculated the whole time. So apparently I need lots of rice hulls. Thanks for all the suggestions.

 

[dk21]

If I remember correctly, Blichmann recommends letting the grain sit uncirculated for 10 minutes before starting the pump. I believe that this helps, though I can't provide any details as to why.

 

[day_trippr]

If I remember correctly, Blichmann recommends letting the grain sit uncirculated for 10 minutes before starting the pump. I believe that this helps, though I can't provide any details as to why.

fwiw, that's pretty much a universal recommendation - Blichmann FB or any other...

Cheers!

 

[SavoryChef]

Yes, I always wait at least 10 minutes

 

[kombat]

I'm telling you, it's the pump. It's drawing a suction on your mash lauter tun. The solution is to employ a grant. I used one today, see this thread for photos of it in action.

 

[SavoryChef]

I'm telling you, it's the pump. It's drawing a suction on your mash lauter tun. The solution is to employ a grant. I used one today, see this thread for photos of it in action.

While I agree that a grant would be a perfect fit here. If I had to use one, I would just throw this Blichmann in the lake for a boat anchor and go back to my old mash tun. I bought this because of the false bottom and how little dead space below it. My old mash tun had 1.25 gallon of liquor below the false bottom, so using a grant to recirculate would give me the same liquor to grist ratio that i didn't like.

 

[kombat]

Why would a grant require you to modify your liquor-to-grist ratio?

 

[SavoryChef]

It would make the grain bed too dry for my liking by removing liquor with smaller beers where the mash volume would equal, say 7-10 gallons or 16-20# of grain.

 

[kombat]

Even if you throttled back the flow rate?