Constantly Getting Stuck Mashes

zgardener · May 1, 2012

I've had my 10 Gallon Igloo MT with a 12" Domed SS False Bottom for about a year and have never had an issue with stuck mashes (I've breweed 30 batches in it no problem). I have a 1/2" bulkhead w/ a 1/2" Brass ball valve to drain.

About a month and a half ago, I was brewing a Black IPA, and it got stuck. I fixed it and figured the false bottom got plugged up with some of the very fine dried from the husks of the roasted malt... then my next two batches got stuck, an amber ale and a wit. Each of my beers I use at least a 1/2 lb of rice hulls, 1 lb for wheat beers... both got stuck.

After that I took apart my mash tun and reassembled it, and my hefe went just fine, not stuck, though it drained a little slow. My next beers tho, an American Premium Lager and a Traditional Bock, both got stuck.

To remedy, I have had to dump the mash into a kettle, then put a small piece of wooden dowel between the wall of the MT and the edge of the False Bottom, which lifted up the edge of the False Bottom about 1/2 an inch or so.
After I do this, the flow is usually fine.

So, all things considered, and I've talked to guys at AHS about this, there is no reason that this should happen, but it does. Has anyone had this problem? Any idea on what could be causing this?

nukonamo · May 1, 2012

zgardener said:
I've had my 10 Gallon Igloo MT with a 12" Domed SS False Bottom for about a year and have never had an issue with stuck mashes (I've breweed 30 batches in it no problem). I have a 1/2" bulkhead w/ a 1/2" Brass ball valve to drain.

About a month and a half ago, I was brewing a Black IPA, and it got stuck. I fixed it and figured the false bottom got plugged up with some of the very fine dried from the husks of the roasted malt... then my next two batches got stuck, an amber ale and a wit. Each of my beers I use at least a 1/2 lb of rice hulls, 1 lb for wheat beers... both got stuck.

After that I took apart my mash tun and reassembled it, and my hefe went just fine, not stuck, though it drained a little slow. My next beers tho, an American Premium Lager and a Traditional Bock, both got stuck.

To remedy, I have had to dump the mash into a kettle, then put a small piece of wooden dowel between the wall of the MT and the edge of the False Bottom, which lifted up the edge of the False Bottom about 1/2 an inch or so.
After I do this, the flow is usually fine.

So, all things considered, and I've talked to guys at AHS about this, there is no reason that this should happen, but it does. Has anyone had this problem? Any idea on what could be causing this?

Are you maintaining a proper water level above the grain bed?

zgardener · May 1, 2012

nukonamo said:
Are you maintaining a proper water level above the grain bed?

During sparge 2" to 3" above grain bed, though, it won't drain at all at any point. I tried re-circulating with a HERMS system, when the problem started, it wouldn't flow, and I've also done a normal mash with a mashout addition and vorlauf, still no flow until I made the fix that I mentioned.

wSelwyn · May 4, 2012

I used to get stuck/slow sparges allll the time. My temp was spot on, and I maintained a good flow and water above the grain bed. Then I noticed something: I had my nut screwed too tight against the false bottom. With the nut hard against the plate, it looked great, but it would knock out of the FB or allow grain to pass through.

To remedy this, I have the nut up higher, so that the brass 90* elbow is just resting in the FB. It doesn't look right at first, but think of the weight of grains + water on the system. I now get clear runnings after vorlauf. No stuck sparges.

This is what works for my system, and assuming that you have the same problem as me with yours.

Backporchbrewery · May 4, 2012

Same thing happened to me and a buddy. Domed false bottom started out working great for 1+ yrs, then the stuck sparges constantly. We both swapped to a s/s braid and haven't had trouble since. My best guess is our coolers warped slightly letting grain under the false bottom.

Brulosopher · May 4, 2012

Potential solution 1: Different type of manifold

Potential solution 2: batch sparge

Cheers!!

pjj2ba · May 4, 2012

Perhaps a build up of beer stone on the manifold making the holes smaller? (easier to plug)

I had this problem with my hop filter. It had become discolored, but I thought nothing of it. Then it started to take longer to drain. I finally thought to give it a thorough cleaning and was surprised at the amount of gunk that came off of what I thought was a clean SS screen. I soaked it in hot oxyclean and then starsan (neither alone worked) and a little srcubbing loosened up tons of gunk that had slowly accumulated in the mesh. The difference in flow was huge!

zgardener · May 4, 2012

thanks for the suggestions.
I added an extra 90 degree elbow to act as a pickup tube, and it lifts the false bottom up by maybe a 1/2", I'll loosen those nuts and see how it all works when I brew on Saturday.

Durhamite · May 4, 2012

Have you been messing with your grain mill gap recently?

zgardener · May 4, 2012

Durhamite said:
Have you been messing with your grain mill gap recently?

I get everything milled at AHS, never had an issue before.

Bsquared · May 4, 2012

You said this started when using a HERMsystem? Are you using a pump?

zgardener · May 4, 2012

Yes, I did.
I had 5 successful brews w/o issue with my HERMS set up, then the problem started.
Last brew I didn't recirculate until my 20 min Vorlauf after mashout water was added (it didnt flow when I did the Vorlauf... I had to remedy the issue before I could recirc.

Bsquared · May 4, 2012

Okay, I see, I had a similar problem when I started using a pump with my HERMS system. First, how is your pump orientated? Is the outlet pointing up and is the head of the pump at least 6" below your mash tun?

Second is your valve all the way open when you turn on the pump?

I found I was having priming issues because I had my pump horizontal, as well if you have the valve open all the way when you start the pump it can create a vacuum and cause the grain bed to collaps and giving you a stuck mash.

What I did was lower my pumps,orientate them vertically a have the inlet at the bottom and the outlet at the top, Prime the pump, and before turning the pump on I would close the valve all the way, then slowly open it after turning the pump on.

I have not had a problem after doing these things.

zgardener · May 4, 2012

Bsquared said:
Okay, I see, I had a similar problem when I started using a pump with my HERMS system. First, how is your pump orientated? Is the outlet pointing up and is the head of the pump at least 6" below your mash tun?

Second is your valve all the way open when you turn on the pump?

I found I was having priming issues because I had my pump horizontal, as well if you have the valve open all the way when you start the pump it can create a vacuum and cause the grain bed to collaps and giving you a stuck mash.

What I did was lower my pumps,orientate them vertically a have the inlet at the bottom and the outlet at the top, Prime the pump, and before turning the pump on I would close the valve all the way, then slowly open it after turning the pump on.

I have not had a problem after doing these things.

Yeah, I'm positive it's not a priming issue, as I would unhook the pump, open the valve on the mash tun all the way and barely get a trickle, or sometimes not even a drop...

Bsquared · May 4, 2012

before or after the pump was turned on?

ALF · May 5, 2012

I've had my 10 Gallon Igloo MT with a 12" Domed SS False Bottom for about a year and have never had an issue with stuck mashes (I've breweed 30 batches in it no problem). I have a 1/2" bulkhead w/ a 1/2" Brass ball valve to drain.

How is the false bottom connected to the bulkhead/valve? It seems one of the connection points is loose and/or open.

zgardener · May 7, 2012

ALF said:
How is the false bottom connected to the bulkhead/valve? It seems one of the connection points is loose and/or open.

with a 3" piece of high heat vinyl tubing, I've checked and double checked to make sure the worm clamps are tight, but that wouldn't explain why it would flow once I dumped out the mash, raised up the back of the false bottom a little, then put the mash back in...

chumprock · May 7, 2012

Backporchbrewery said:
Same thing happened to me and a buddy. Domed false bottom started out working great for 1+ yrs, then the stuck sparges constantly. We both swapped to a s/s braid and haven't had trouble since. My best guess is our coolers warped slightly letting grain under the false bottom.

Similar, but I just got a new false bottom.

OP, does your false bottom sit completely flush against the bottom of the cooler, or is it warped at all? If its warped, it will allow grains in through those cracks which can cause this kind of displeasure.

zgardener · May 7, 2012

chumprock said:
Similar, but I just got a new false bottom.

OP, does your false bottom sit completely flush against the bottom of the cooler, or is it warped at all? If its warped, it will allow grains in through those cracks which can cause this kind of displeasure.

I'm starting to think that may be my issue, the inside of my MLT has started to bubble up in a few places, and the false bottom doesnt sit 100% flush on the bottom. Could a screen, or piece of cheese cloth help with this?
I've heard of some people using SS scrubbies as crude filters, maybe I could use that as a secondary filter on the pickup?

chumprock · May 7, 2012

Well, when I noticed mine was warped I tried using a ring of vinyl tubing around the edge of the false bottom as kind of a "seal". While it did fix a lot of it, there were still noticable gaps and I wanted to throw away money so I just bought another one..

You might try that before investing in more equipment. Just get a section of tubing that fits the circumfrence of the false bottom, and slice it lengthwise to create a rudimentary "gasket".

Constantly Getting Stuck Mashes

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