Ridiculously Stuck Sparge

I had a hell of a brew day yesterday. It was my first attempt to do 2 batches in one day, essentially simultaneously. I figured I could handle it after 2 years.

I made an AB clone and an Oatmeal Stout. I had everything in place. All the grain crushed, the hops pre-measured and ready to go, and I'd worked out a pretty good plan for timing everything.

The problem started with a stuck sparge on my AB clone. I batch sparge. I've experienced a few stuck sparges, but a quick swirl with my mash paddle generally clears them up. This was the mother of stuck sparges. I couldn't get a drop out of the mash tun no matter what I did. I ended up pouring the contents of the mash tun through a paint bag into a 5 gallon pail and doing an impromptu hybrid BIAB. It was the only way to get the liquid out of the mash tun. Even when I tried to hose out the mash tun later, the remaining grain was jamming it up. My garage floor is a sticky mess.

Somehow I hit my numbers though - go figure.

First - what would cause a mash tun to jam up like this? At first I thought maybe it was the grain crush, but I didn't have any problems with the stout; even with roasted barley. I used Special B and Aromatic malt in the AB clone. Could it be the type of grains?

Second - I'm guessing all my pouring between buckets did a number on the wort. How bad of a problem will oxidation be? I've never had to do this before so I'm not sure what to expect.

Second question first, Oxidation is only a concern once the beer has fermented out so no problems there.

First question, stuck sparges are usually related to too fine a crush and the grain bill, typically a lot of wheat. If this continues to be a problem I recommend you add rice hulls to the grain bill. They are course and act as a filter for the grain bed.

What type of manifold do you have or screen? False bottom? If these items are not fitting properly or the holes are too small they can plug up pretty good as well!

I was worried more about hot-side aeration. There was a lot of splashing going on when I was pouring hot wort between buckets.

I'm assuming the crush was fine based on the fact that I only had problems with the one beer. I've read in a few places that some of the roasted grains can cause problems because the don't really crush as much as fracture. Just wanted to see if special B or aromatic malt had a tendency to do this.

I have a copper manifold. It is soldered. I've had minor stuck sparges once or twice, but none like this one.

I'll try the rice hulls. I've never used them, but if they keep this from happening again they are worth it.

+ 1 on rice hulls, and I'm not sure if you do this already but if not, I recommend running out the wort very slow when you first vourloff. I just barely open the valve. It seems to help.

Stauffbier said:

+ 1 on rice hulls, and I'm not sure if you do this already but if not, I recommend running out the wort very slow when you first vourloff. I just barely open the valve. It seems to help.

Click to expand...

+1 I used to have issues with my sparges as well, but once I started using hulls those problems went away. Definitely vourloff with the valve barley cracked open as well.

Do you mix the rice hulls in with the grain, or put them at the bottom of the mash tun?

Soak the hulls in water then put them in the mashtun as a bed then add grain so rice is a filter of sorts

b-boy said:

Do you mix the rice hulls in with the grain, or put them at the bottom of the mash tun?

Click to expand...

I typically add the rice hulls after dumping half the crushed grain into the mash tun. I then pour the rest of the crushed grain in and mix as usual. I've found that this method gives a good distribution of the hulls into the grain and prevents stuck sparges. I do use a false bottom (NorCal) in my keg mash tun.

generally wheat is the major culprit causing stuck sparges. I never had a issue with any other grains. If it was my system I would try using a braid or bazooka and see if that works better for you. I have never had a stuck sprarge using a braid. and I do 10 and 15 gal batches so I'm using large volume of grain.

Stauffbier said:

+ 1 on rice hulls, and I'm not sure if you do this already but if not, I recommend running out the wort very slow when you first vourloff. I just barely open the valve. It seems to help.

Click to expand...

Never used rice hulls but +1 on the slow vourloff... I think this is mainly to avoid channeling that could produce compacted grains around your manifold.

b-boy said:

Do you mix the rice hulls in with the grain, or put them at the bottom of the mash tun?

Click to expand...

I put my rice hulls in a paint strainer bag and shake the dog p*$$ out of it outside to get all of the dust out, then I mix it in with my grain bill and add an extra cup or two of water to my total volume. Works like a champ!

b-boy said:

Do you mix the rice hulls in with the grain, or put them at the bottom of the mash tun?

Click to expand...

I just mix mine right in with the grain when I dough in. My thoughts are that they do more work for you in terms of preventing a stuck mash if they're distributed evenly throughout the grain rather than just acting like a filter below the grain. I feel as if you could still get channeling or "sticking" throughout the grain bed if the hulls just in a layer at the bottom, but I could be wrong...

I haven't had a need to add any extra water to the mash or pre-soak them either - though that could depend on your equipment.

Stauffbier said:

I put my rice hulls in a paint strainer bag and shake the dog p*$$ out of it outside to get all of the dust out, then I mix it in with my grain bill and add an extra cup or two of water to my total volume. Works like a champ!

Click to expand...

Can I ask why you do this, why are you worried about dust from the rice hulls?

biestie said:

Can I ask why you do this, why are you worried about dust from the rice hulls?

Click to expand...

Mainly just to keep from adding more small particles to my grain, but to be honest I'm sure it doesn't really serve any good purpose. Maybe it just makes me feel like it's "cleaner" some how. Chalk it up as one of my strange quirks!
I've known people that like to rinse them out first as an effort to clean them.

To the OP. How do you have your manifold oriented? Slots up or down? I know this is debatable, but if you have them facing up, try facing them down. My manifold clogs like a mother when the slots face up. I think this is becasue my slots ended up a little too wide and the grain is able to get inside and wreak havoc. I always face my slots down now and never have any problems. Just a thought.

I actually have holes drilled, not slots. They are down and on the sides. The manifold lifts a little off the bottom of the cooler. That might be an entry point. I've really never had a problem like this before and I've done a few dozen batches in this cooler.

I took a look at the spent grain and it looked like some of the grain was sheared as opposed to crushed. I'm guessing it was the type of grain used. Each piece was just the right size to plug up one of the holes in the manifold. When I swirled the wort, they would quickly dislodge, but immediately plug up again. I re-tested it by adding some grain and water into the tun. I could see the grains plugging up the manifold.

I'm going to pull the manifold and cut some slots. This should prevent a total clog in the future.

I appreicate the help.

I've never had a stuck sparge but I take steps to prevent them. I first wrap my manifold with cheesecloth. I vorlouf very slowly. If I'm making a beer that will have a thick mash then I'll add rice hulls. IMO, the reason why I haven't experienced a stuck sparge is due mainly to the cheese cloth. Cheese cloth adds a couple bucks to your ingredient list but that couple extra bucks is well worth it if you never experience another stuck sparge.