Need help for trouble shooting my issue

[Rys06Tbss]

I have been making all Grain batches for over two years now. I use a 15 gallon keggle with a 12" domed false bottom. I usually crush my Grain at the brew store but if I'm rushed I'll grind it in my Corona mill. I usually get between 85 and 90 percent efficiency with my grind and the brew store is about 80.

About a month and a half ago I made an imperial stout with about 30 lbs of grain. I use a Rims and towards the end of the Mash, I noticed my pump sounded strange and there was a slow trickle coming out. After I was done, I dumped the grain and foumd my false bottom had collapsed. I figured it was just to much Grain. A week later I made a beer with 4 lbs of 2 row and 3 lbs of wheat with half a pound of rice hulls. That stuck right away but I was able to clear it. False bottom collapsed again.

Last weekend I was going to make a Saison that had 21 lbs of grain with flaked rye and flaked oats. I ground all the grain for this on my mill. After about 10 minutes I heard a pop and the flow went to a trickle. I transfer the grain to a bucket and popped the bottom back into place. Dumped it all back in and again it collapsed. I was pissed so I committed a sin and dumped all the grain in the garbage.

So my question is... What could be causing this. I'm guessing I should loosen my grind up? Maybe add rice hulls? I really havnt had to use hulls at all I the past until recently. I feel it would just be a band aid to my issues.

 

[fixitoscar]

So is it a false bottom problem or a sticking sparge problem? IMO even if the sparge gets stuck your false bottom should not collapse. You could try lowering the pump flow.

 

[bknifefight]

What is your false bottom made of? I have a hard time imagining the scenario and how this is happening if it is stainless steel.

 

[bu_gee]

I think your false bottom might be tired. Metal has a tendency to deform in the exact same way it had deformed in the past and develop a bit of a "memory" when something like that happens. Actually, many materials do that, not just metals.

Can you post photos of your collapsed and uncollapsed false bottom? It might help diagnose.

 

[Rys06Tbss]

It is stainless. I'm guessing it's tired. I'm guessing what's happening is its sticking and just collapsing it.

 

[Rys06Tbss]

So quick update. I made a Nelson Sauvin Pale ale 3 weeks ago. All went well. Today, I making a Imperial stout with 28 lbs of grain and the ****er stuck again. This time I put some stainless screws on in my false bottom to prevent it to completely collapsing. I put in a lb of rice hulls. I mashed in and could tell it was way to thick at the start. So i threw in another gallon of water. I think I might need to start using a little more water in my grist. 1.25 isnt cutting it for these big beers. Anyhow I started my recirculate like I would normally do. it was flowing great then is slowed a trickle. I ran my full mash and added another 15 minutes. I was able to run off about 5 gallons through gravity. I was hoping my sparge would go better but no dice. So Im slowing trickling the remaining 4 gallons of sparge water. Im not please. Ill take pictures when I dump the mash tun.

 

[Rys06Tbss]

I ended up hitting 1086 before boil. I'm happy.