Stuck Sparge - Round Cooler With False Bottom

[bburleson]

I bought one of the false bottom kits for a 10 gallon round cooler. The pipe between the false bottom and the valve was solid SS. Checked it for leaks, and was ready to brew...
When I completed my mash, I opened the valve, got a few ounces of clear water, then nothing. Opened, closed, opened closed, etc., but couldn't get anything flowing. Stirred the grain bed, let it settle, still nothing.
I could blow air in through the tube (bubbled through the grain), which still didn't get anything flowing. But when I then tried sucking, I thought I'd have an aneurysm, as the sparge was majorly stuck.
Since I could blow through the valve, I know there weren't grains blocking it. But, before I go through the headache of dumping the cooler on my next mash, any ideas what may have caused this?

 

[mgortel]

Grain was crushed to fine possibly. Still seems weird you only got a few ounces before it stuck.

Silly question....you didn't have the lid on did you. That would create a vacuum possibly preventing flow

 

[Konadog]

Is it possible that the false bottom was smashed all the way down (no dome) and the pipe was trying to suck the bottom, thus blocking the drain pipe?

 

[bburleson]

Grain was crushed to fine possibly. Still seems weird you only got a few ounces before it stuck.

Silly question....you didn't have the lid on did you. That would create a vacuum possibly preventing flow

Had the lid off, and witnessed the grain bubbling when I blew in through the hose.
I was thinking the grain might have been milled too fine. But, when I blew in, and disturbed the bed, wouldn't that free up something?

 

[bburleson]

Is it possible that the false bottom was smashed all the way down (no dome) and the pipe was trying to suck the bottom, thus blocking the drain pipe?

The false bottom is a domed one, and the fitting at the end of the elbow (under the FB) has notches in it, so it shouldn't create a vacuum with the bottom...?

 

[Konadog]

You could try to fill your tun with water, open your valve and if you have a decent flow, push down on your false bottom and see what it does.

What was your grain bill? Is it possible that something was under the false bottom that would get sucked over the drain opening, blow it out only to have it get sucked back?

 

[bburleson]

You could try to fill your tun with water, open your valve and if you have a decent flow, push down on your false bottom and see what it does.

What was your grain bill? Is it possible that something was under the false bottom that would get sucked over the drain opening, blow it out only to have it get sucked back?

I ran it with water a few times prior to brewing - the only difference would have been hot water, versus room temp.

The grain bill was just over 10lbs - with some wheat, but mostly 2-row. After I eventually got things flowing (in a kettle with a filter screen), the grain bed was pretty tightly packed. Suppose I may have had something pick up in there, and immediately suck back in.

 

[Qhrumphf]

If you're opening the valve fully right away that can be the problem. As said, suction collapses the dome and the dip tube can get pinned to the bottom. Open the valve slowly and only part way, especially at first.

 

[Qhrumphf]

You don't need a pure vacuum to stop flow, just enough lack of intake to balance the outtake.

A friend though his mashes always stuck. Turns out he was leaving the lid on to save temp. It's not airtight but close enough. I've heard of folks using pumps actually collapsing mash tuns that way.

 

[jalc6927]

Make sure the fitting is tightened to the elbow on false bottom, if it’s loose it could cause stuck Mash/ sparge

I went to using a brew bag and it’s never an issue anymore

Highly recommend using the bag inside your cooler

Some may sneer at those who use the bag, but who cares, it prevents a major hassle from occurring

 

[ancientmariner52]

Air bubbling up when you blew back through the drain valve wouldn't tell you very much. Consider the area under the false bottom. It won't take much pressure to lift the entire assembly so that air leaks all around the perimeter. Think of it like a piston in a cylinder.

 

[DurtyChemist]

Figure this out yet?

It's possible the weight of the grain and water was too much for the false bottom and it collapsed so the little bit of wort you saw was all it could hold in the center. The tube from the false bottom to the valve could have been pinched off and allowed air but not much water. I'd fill it to the top with water and see if the 80 lbs of water weight is too much for the false bottom.

 

[ancientmariner52]

A flexible/collapsible tube between FB and outlet? That would do exactly What OP describes. OP, a photo could help us figure this out.

 

[bburleson]

Sorry for the delayed response... and lack of photo. I had a solid connecting pipe between the FB and valve (so no crushing weight issues). Became concerned - didn't want a repeat - so, my last couple of brews have been a modified BIAB method. I use my same mashtun set-up, but as a precaution use a bag. These last two have worked as planned - and no stuck sparge.

 

[EtchyLives]

I used to have the same problem with my cooler mash tun set up the same way as yours. Only the most basic of grain bills (all barley) could get me a normal sparge and even then if I drained the wort too quickly my grain bed would bind up quick. This was with a 0.035 gap on my grain mill.

I did the same thing you did - went to a mash bag - and never looked back. Easier mash, higher efficiency, no stuck sparge, and easy clean up. I changed to an SS Brewtech heater mash tun and still use the mash bag because it works so well.