Stuck Sparge In New Mash Tun

[Florian]

Just started my brew night on my new gear. Everything seemed to go to plan, HLT was heating up quickly, pre warmed the mash tun with hot water and let it drain off, then mashed in. Out of curiosity, being a new mash tun, I though I would recirculate a little bit, just to see how well the wort drains from the tap. Open the valve, and - nothing. Not one drop coming through. Well, a few drops came when I tilted the whole tun forward.
The only way to explain it is that the grains went through the false bottom and completely blocked the pick up tube. The false bottom can't be all blocked as there obviously was water sitting underneath it as well. Total grain bill of 6.6kg, including 1kg rice hulls, 1.5 kg wheat and 1kg rye.

Seems like I will have to empty the tun by hand into a pot, and then - then what?
sparging through a sieve? clear the tubing and cover with swiss voile? Forget about the batch?

Any ideas?

30 minutes left...

Thanks
Florian

here are some photos of the tun, so you get an idea:

 

[manticle]

I had a stuck sparge today. Basically you can try the following -

1.Try and rake as much grain away from the drain hole as possible
2. Blow through the tube to clear and try again
2. If this fails, scoop out as much grain as possible, gently remove wort into another vessel, clear, then place everything back and try again.

My stuck sparges have only ever happened because the manifold has come away from the t-piece - the manifold itself seems resistant to blocking. In my case 1 and 2 do nothing, 3 always works.

However it seems to me as if the positioning of your drain may have something to do with it. Any reason you placed it centre bottom?

I'm no expert so don't go changing it just because I said anything but I'd research to see if that's ideal or if it's a possible blockage causal factor. Gravity and everything is going to rush to that one point. If you use the drain already there on the side I reckon you'll fix the problem.

Add to that Rye is meant to get pretty gluggy and that could be it.

 

[browndog]

What sort of clearance is there between the outlet and the false bottom, Manticle could be right in that the weight of the grain is forcing the false bottom down onto the drain thus giving you about 6 holes to drain though.

cheers

Browndog

 

[Florian]

Wow, thanks so much!
Didn't think of it myself, so just blew into the tap, and guess what? I ended up with a mouth full of wort and grain, perfect. And the wort kept flowing, so this should have solved my problem. if it blocks up again, I will just blow again and might loose a mouthful of wort, which I can live with.
Will see how I go with the position of the drain, but the idea is to reduce dead space to almost zero.


I was hesitant in posting this up tonight, but am glad I did.
Thanks Manticle for the quick fix.

Florian

 

[MHB]

I strongly suspect that the floor isn't quite as ridged as you would hope and that the weight of the grain be has pushed the mesh down and basically put a plug in the hole.

Try cutting a little spacer some 30-50 mm PVC or similar pipe, to support the centre of the floor, cut some notches in the edge that faces the bottom of the tun, put it over/around the outlet, allowing the sweet water to flow in from the sides.
Should fix you up

MHB

Mantickle - However it seems to me as if the positioning of your drain may have something to do with it. Any reason you placed it centre bottom?

Naturally, as it's the best place, you have the best chance of getting even sparging of all of the grain bed.
M

 

[Florian]

What sort of clearance is there between the outlet and the false bottom, Manticle could be right in that the weight of the grain is forcing the false bottom down onto the drain thus giving you about 6 holes to drain though.

cheers

Browndog

There are about 2-3 cm I reckon. The false bottom is rock solid though, absolutely no chance of it being pushed down.
But problem solved anyway, thansk for your help guys.

Florian

 

[winkle]

Perhaps the crush is a bit fine and getting through the mesh. If you've emptied it out try some stainless steel wool over the inlet (inside the falsie), it might help.

Otherwise try blowing up the pipe to clear, drain some, blow to clear etc, - it'll be tedious.
Best I can think of, sorry if this is too late.

Edit: too late (bloody slow typing) but glad it worked out for you.

 

[manticle]

Naturally, as it's the best place, you have the best chance of getting even sparging of all of the grain bed.
M

Good to know, cheers.

Never seen it done that way before (not that that necessarily means much at all)

 

[MHB]

Every one of the commercially made FB's (the domed stainless) ones available through above sponsors has a centre bottom pick up.
Palmer covers FB and manifold design and construction fairly thoroughly worth a read.

MHB

Edit/Correction
Sorry just went and refreshed the memory, he covers Manifold design very well but doesn't talk about False Bottoms, same design rules apply however. If you have a look at his work see figure 173, think of a FB as a manifold with dozens/hundreds of pipes.
M

 

[raven19]

Some Rice Hulls added to the mash with all that Rye would be beneficial also.

 

[manticle]

Every one of the commercially made FB's (the domed stainless) ones available through above sponsors has a centre bottom pick up.
Palmer covers FB and manifold design and construction fairly thoroughly worth a read.

MHB

Edit/Correction
Sorry just went and refreshed the memory, he covers Manifold design very well but doesn't talk about False Bottoms, same design rules apply however. If you have a look at his work see figure 173, think of a FB as a manifold with dozens/hundreds of pipes.
M

I'll have a squizz. My manifold was designed partly on what I read in Palmer but mainly based on what I've read here and elsewhere (as well as pictures). Copper manifold in Esky tun - I'm not massively familiar with false bottoms. It seemed to my mind that the weight of the grain + gravity might make that design more prone to a stuck sparge but as I said - my immediate reaction only and not to be taken as sage advice.

Anyway I'm upgrading my tun soonish so I'll do some more reading. Always good to learn something new - to me that's half the fun in brewing.

Cheers

 

[bjay]

I have a false bottom in my mash tun ,,,,
But i made spacers up to stop it sagging with the weight of wet grain
So the spacers go all the way to the bottom for support

cheers
bjay

 

[Florian]

Thanks for all your input guys. My brew night is finally over, has taken longer than expected, as usual. Only had to blow a few more times, which wasn't a big issue for me. Might try that steel wool or something similar next time, Winkle.
Raven, I had already 1kg of rice hulls in my grain bill, which did a great job. The grain bed drained perfectly even, especially because the ss mesh covers the whole floor area. It's only the drain that got blocked, probably because the 90 degree angle in the piping.

Anyway, off to bed now...
Florian

 

[Screwtop]

Thanks for all your input guys. My brew night is finally over, has taken longer than expected, as usual. Only had to blow a few more times, which wasn't a big issue for me. Might try that steel wool or something similar next time, Winkle.
Raven, I had already 1kg of rice hulls in my grain bill, which did a great job. The grain bed drained perfectly even, especially because the ss mesh covers the whole floor area. It's only the drain that got blocked, probably because the 90 degree angle in the piping.

Anyway, off to bed now...
Florian

Bit late, but here is something to try next time........don't stir the mash any more than required just to mix and break up any lumps, then open the valve slowly. You want the very first runnings to just dribble out as there will be lots of particulate matter below the FB, open fully and you risk plugging up the outlet with gunk before clean wort begins to run. My system does the exact same thing, when I begin recirculation I just crack the valve to begin with, before opening it up.

I also have a question: Why add water to heat the tun then drain it off? Add strike water, wait 5 min to warm the tun and then add grist, this also reduces the temperature differential between the brewing liquor and grist at mash in.

Cheers,

Screwy

 

[Florian]

Thanks, Screwy,

That's what I initially did, opened the valve completely, so it got blocked straight away. Gotta be more patient...

I pre heated the tun just because I forgot to include it in my strike water temp calculations, and did not want to be out because of the cold tun. Only added 2 litre of boiling water, kept for a few minutes, then drained before adding strike water. In my situation It had the benefit that at least I knew that everything was in working order and that it must've been the grist that blocked the pipes. But in future I will save that step and just up the strike temp accordingly.

That was my first round with this mash tun and my other new gear, so am still adjusting as I go. It worked out in the end, although I have unfortunately sparged a round to much (was convinced that the grist would still give me another good gravity run, but it didn't) and ended up with a lower pre boil gravity as expected. Even worse, I did not boil it off (as it was very late at night), so am now left with a no chill cube full of wort around 1.040ish. Not quite sure yet if I boil it up again (only bittering hop additions) to reduce the volume and up the OG or bite the bullet and have a mid strength beer.

Florian

Edit: Also got about 7-8 litres of trub-wort mix in a separate container, as again, it was late and I was too tired to wait until the whirlpool settles completely.

 

[Screwtop]

Thanks, Screwy,

That's what I initially did, opened the valve completely, so it got blocked straight away. Gotta be more patient...

I pre heated the tun just because I forgot to include it in my strike water temp calculations, and did not want to be out because of the cold tun. Only added 2 litre of boiling water, kept for a few minutes, then drained before adding strike water. In my situation It had the benefit that at least I knew that everything was in working order and that it must've been the grist that blocked the pipes. But in future I will save that step and just up the strike temp accordingly.

That was my first round with this mash tun and my other new gear, so am still adjusting as I go. It worked out in the end, although I have unfortunately sparged a round to much (was convinced that the grist would still give me another good gravity run, but it didn't) and ended up with a lower pre boil gravity as expected. Even worse, I did not boil it off (as it was very late at night), so am now left with a no chill cube full of wort around 1.040ish. Not quite sure yet if I boil it up again (only bittering hop additions) to reduce the volume and up the OG or bite the bullet and have a mid strength beer.

Florian

Edit: Also got about 7-8 litres of trub-wort mix in a separate container, as again, it was late and I was too tired to wait until the whirlpool settles completely.

All good F

If your gravity is not out by much you can add some sugar or dme to the ferment after a few days.

Screwy