Stuck mash in BIAB?

[sablesurfer]

(I thought there was a BIAB forum? Did it go away or am I hallucinating?)

So last night I attempted a RIS using BIAB on my electric system and recirculating during the mash. I decided to attempt the recipe in two mash cycles because ~20lbs grain too much for my kettle in one go.

First mash no problem

Second mash, I start smelling scorching wort about 5 minutes after mash in. The volume in pot appears to have risen by half again. After much messing around the bag slips off pot and falls down....SPUOOOSH! Now volume back to expected but I have wort splashed everywhere.

I turn pump back on and again the bag fills up. Lifting the bag out later it is LITERALLY (used appropriately) like a water balloon. It is holding liquid and even squeezing produces not much other than a tiny pinprick of wort shooting out here and there.

After digging all that out and moving to another bag, I can get some flow, but I have to continually scrape down the sides of the bag for rest of the mash.

Anyone else heard of, or had, a stuck mash in a BIAB?? This is was a surprise to me.

 

[jtratcliff]

Hmmm... Never had one myself.... What was your grist like?

I've a little slowing with canned pumpkin in the mash but shifting the bag around was enough to keep it going.

My wilserbrewer bag is definitely finer mesh than the Ikea voile curtain I was using before. But still never managed to get it stuck

 

[jtratcliff]

BTW the BIAB forum is a sub-forum of the All Grain forum.

 

[trimixdiver1]

First off, your not doing a true BIAB. You are recircing. So blame your process, not BIAB. Your increasing the chance of a stuck mash.

 

[sablesurfer]

This is close the 15th brew on this system and first ever stuck.

It was a RIS, and I was reading that the black malts can be an issue?
I have been using Lowes paint strainer bags this whole time with no problems.
Base malt was all maris otter, but like I said, first half went fine.
Also adjusted the grain mill this time, from .37 to .35, wonder if that crushed black malts too much?

<shrug>

Ah...all grain, doh! , how do you get a thread moved?

 

[jtratcliff]

First off, your not doing a true BIAB..

no true Scotsman ....





Why would recirculating lead to an increased chance of a stuck sparge?

I don't recirculate so I don't have any direct experience but it doesn't seem to be inherently "sticky"... Is there something about recirculating that is problematic?

 

[LLBeanJ]

I don't recirculate, but I've had some difficult BIAB lauters. They've all involved wheat, rye, or pumpkin, though. With some repositioning of the bag they all drained eventually. I would think with recirculating you would be pulling the wort faster than if allowed to drain via gravity, so I could see how that might make the situation more difficult.

 

[sablesurfer]

I don't recirculate, but I've had some difficult BIAB lauters. They've all involved wheat, rye, or pumpkin, though. With some repositioning of the bag they all drained eventually. I would think with recirculating you would be pulling the wort faster than if allowed to drain via gravity, so I could see how that might make the situation more difficult.

I have the ability to throttle my recirc using a ball valve on the outflow. Didn't help. In this instance I pulled the damn bag out of pot and held it there. It BARELY dripped, was exactly like a water balloon when I laid it in my giant collander to try to press liquid out.

 

[ong]

It seems to me that every time I lift and drain the bag, it drains a bit slower, like if I do a mashout. I've hypothesized that each time, I'm sort of plugging a bit more of the mesh with grain particles. I wonder if recirculating has that effect, where you're continually forcing bits of grain into the mesh? Or perhaps just continually "sorting" the grain by moving smaller bits into the crevices between larger bits, resulting in compaction/higher grain density.

 

[alewhatcuresyou]

I use a 400 micron stainless mesh basket, and recirculate through a rims tube. I have noticed slower draining when using a finer grind or wheat. I have started throwing in 3 or 4 large handfuls of rice hulls and it certainly helps.
Before I bought the basket I used a bag. I once had a stuck sparge that collapsed and ruined a false bottom due to the pump sucking all the wort out from under the bag and nearly overflowed the pot.

 

[Owly055]

I find this interesting...... particularly because I am trying to do a recirculating BIAB process myself......... Saturday's brew had to revert back to hand stirring because the brew bag seemed to be blocking the pump suction, though the suction was designed to prevent this. I built a sort of false bottom to alleviate the problem, and hopefully this will work. worked fine with straight water at mash temp, so the bag had to be the problem.

I built a sort of false bottom just to keep the bag off the bottom of the pan, and this evening decided to do a test brew. I started at 6:30, and am 15 minutes from the end of the boil 7:55. A half hour boil......... an extremely vigorous wild rolling boil.

I used my recirculating pump which is a cheap Chinese plastic pump......the one people are talking about. It moves enough water to do the job for me, which isn't too much. My grind was ultra fine double (.010 spacing), and had exactly the problem you describe, but not quite as much of a problem, At one point the bag seemed to want to lift and burped itself, after that it was fine. The real issue was that the fines seemed to fill the weave of the bag, and it held far more wort than usual and took longer to drain. I always squeeze, but this was far more than normal..........oops. Pardon the interrruption, I had to toss the 10 minute addition in. Time to get the water going in the chiller, etc...... I'll be back in a few minutes............................................ All set for end of boil, chill, transfer, and pitch.... 7 minutes to go. This is roughly a 90 minute process, and I'm finding time to write and have a beer. Instead of rushing, I decided to relax a bit and I find I get things done more efficiently. Everything is picked up and cleaned up and put away except what I am using and will shortly be using.

Clearly there is a problem recirculating in a fine mesh bag with a fine crush. I wish I could reverse circulate, which would eliminate the problem, but I'm not sure how I would accomplish that. Eventually I plan on building a recirculating mash tube with screen, but that won't work with an ultra fine crush either I suspect, but I can automate it enough that using a slightly courser grind won't be an issue...Gotta go again. End of boil is one minute away....................................................
8:10.......... everything picked up, washed, put away. I'm waiting for a small amount of wort to clear so I can take OG readings. Not bad...... One hour and 40 minutes. I used a 20 min mash (approx), and a 30 minute boil. My chill took 7 minutes instead of the usual 5 because I didn't immerse the kettle in a pot of cold water this time......What's 2 minutes between friends ;-).......... I'm drinking a "Northern Amber". Northern Brewer is a hop I really like.

I did this evening's brew just for you ;-) ......... to see if I could replicate the problem you were describing........... and because I hate to see an empty fermenter.


H.W.

 

[sablesurfer]

I once had a stuck sparge that collapsed and ruined a false bottom due to the pump sucking all the wort out from under the bag and nearly overflowed the pot.

Ditto! I was using a cheap steamer basket with some bolts as my false bottom. That one was my only other 'big' brew and it was flowing ok, so I chalk it up to the grain so tight against sides only bottom could flow.

Aint this a fun hobby?!?! LOL.

 

[sablesurfer]

I find this interesting......

I used my recirculating pump which is a cheap Chinese plastic pump......the one people are talking about.

I upgraded to the super fancy black pump from solar whatever instead of the brown one.

My grind was ultra fine double (.010 spacing), and had exactly the problem you describe, but not quite as much of a problem

Holey fine powder batman! I am no where near that, was this a typo?

I'm drinking a "Northern Amber". Northern Brewer is a hop I really like.

Now you have to share.

I did this evening's brew just for you ;-) ......... to see if I could replicate the problem you were describing........... and because I hate to see an empty fermenter.

Awww...oh, wait.

Yeah, the paint strainer bags are pretty fine holes, I did reach out to the guy that makes the hop strainers, but he wasn't interested in doing something along the lines of a BIAB replacement at the time. Still wondering if it was the dark grains in mine..hmm.

 

[Owly055]

I upgraded to the super fancy black pump from solar whatever instead of the brown one.





Holey fine powder batman! I am no where near that, was this a typo?



Now you have to share.



Yeah, the paint strainer bags are pretty fine holes, I did reach out to the guy that makes the hop strainers, but he wasn't interested in doing something along the lines of a BIAB replacement at the time. Still wondering if it was the dark grains in mine..hmm.

I used a feeler gauge to set the rollers.............Granted it's extreme, but my object is to reduce mash time to a minimum. I get total conversion in about 5 minutes!! The Beta Amylase takes a bit longer, so somewhere between 20 and 30 minutes mash time gives me the same result as an hour mash with a "normal" crush. I get a little more trub... but not much.

This is part of my program to cut my brew day from 4.5 hours down radically. I brewed yesterday evening in well under 2 hours. 20 minute mash, 30 minute boil, 7 minute chill....... the rest being heating time and setup / cleaning / take down time. I had about 20 minutes left out of 2 hours!! Needless to say, I'm pushing the limits...... It's a dirty job, but somebody's got to do it.......... ;-)

I don't even intend to describe my next experiment.......... It's too outrageous. I'll tell the story if it works.......maybe if it doesn't.

H.W.

 

[sabitu]

With a recirculating BIAB system you don't want a really fine crush or you will get a stuck sparge. I use a recirculating BIAB system and my Monster Mill MM2 gap is set around .042. I consistently get 76% mash efficiency. I could probably go a little finer and up my efficiency but hitting 76% consistently is fine with me.

 

[Owly055]

With a recirculating BIAB system you don't want a really fine crush or you will get a stuck sparge. I use a recirculating BIAB system and my Monster Mill MM2 gap is set around .042. I consistently get 76% mash efficiency. I could probably go a little finer and up my efficiency but hitting 76% consistently is fine with me.

I found this out the hard way............ Clearly with my ultra fine crush BIAB is the only option, and recirculation does NOT work. I saved my bacon with considerable effort squeezing the bag.

With ultra fine crush, I'm getting right at 90% efficiency on most brews...... from slightly below to slightly above. I didn't even think that was possible with any process. Brewer's friend is my design tool. I look at my results, and adjust brewhouse efficiency settings until my result matches the figure it generates. Stirring is the only method that really works for my ultra sort mashes. (between 10 and 20 minutes).

My next piece of equipment will be a "French Beer Press"........... I'll have to order the screen custom to fit my kettle....... But I'll have the only one on the road!!

H.W.

 

[KimJohansen]

High water to grain ratio combined with a false bottom does it for me.

 

[sablesurfer]

High water to grain ratio combined with a false bottom does it for me.

Does what? Makes stuck or avoids stuck?

 

[The_Bishop]

There's a good likelyhood that folks are taking the 'BIAB fine ground grist' a bit too far. If you're hell-bent on making flour out of your grist, try conditioning it first; the husk will remain more intact and help with lautering/draining. I mill at .032 with conditioned grain and get a terrific grist with no lautering issues and a moderate amount of flour; the starch is more of a very fine grits consistency. I don't know if there would be any gain in going finer, even with BIAB.

 

[KimJohansen]

Does what? Makes stuck or avoids stuck?

Avoids stuck

 

[YNOT2K]

I've had semi-stuck mashes in my BIAB with recirculation. I've tried slowing down the recirc, not much help. It happens every time with wheat and once in a while with dark grains. I feel your pain. I'm thinking of adding a mash tun and ditching the bag...

 

[Owly055]

There's a good likelyhood that folks are taking the 'BIAB fine ground grist' a bit too far. If you're hell-bent on making flour out of your grist, try conditioning it first; the husk will remain more intact and help with lautering/draining. I mill at .032 with conditioned grain and get a terrific grist with no lautering issues and a moderate amount of flour; the starch is more of a very fine grits consistency. I don't know if there would be any gain in going finer, even with BIAB.

I'm the "folks" that are taking BIAB fine ground grist a bit too far....... as you say. .010 is without a doubt extreme. Efficiency and speed are very good, but I get a bit more trub..... equivalent to about half a bottle of beer in a 2.5 gallon brew. This small loss probably balances out the efficiency improvement, but it also allows for extremely short mash times. I typically mash in the 20 to 30 minute range, and achieve complete conversion in well under 10 minutes, the additional time being for fermentability (beta time).
This fine crush clearly does NOT work for recirculating BIAB as it causes a stuck sparge. To successfully recirculate it would be necessary to recirculate within the bag, not through it. This would mean designing a pump that would move both wort and grain. Not an impossible challenge by any means, but it also means that bottom heat is not practical. The real question is "is it worth it"............ and the answer obviously is NO, considering the fact that 20 minutes of stirring and monitoring really isn't a big ordeal.

Now that I have delved into the area of minimizing mash time as a way to reduce my brew day, I'm looking at other approaches. I just put together my 2500 watt floating heating coil, which will cut my time to mash temp and time to boil drastically when used in combination with my "pumped up" kitchen stove burner (gas). I was able to increase BTU output on my kitchen stove by an estimated 50% with a simple adjustment.
My ultimate goal is to set up a reverse flow mashing system on the principle of the Braumesister, but using a chugger pump and a separated and elevated grain basket. This will allow the mash to start before I wake up on brew day. The grain will be high and dry in it's basket / tube set up the night before. The heat will come on and the pump will start in sequence, with a thermo switch turning on the pump, which will then cycle on and off with the purpose of keeping the upper and lower screens clear.

H.W.

 

[The_Bishop]

when used in combination with my "pumped up" kitchen stove burner (gas). I was able to increase BTU output on my kitchen stove by an estimated 50% with a simple adjustment.

Be careful with this. Even if the flame looks clean it's more than likely producing more carbon monoxide, probably enough to create dangerous levels of it in your kitchen. I did the same experiment on my own stove, and using a CO meter showed elevated and near dangerous levels of CO within 20 minutes of starting the burner on high, and it had a clean blue flame that left no soot behind. CO poisoning is no joke, as it has a cumulative effect; CO bonds to the hemoglobin in your blood more readily than oxygen and doesn't let go, which reduces your blood's capability to carry oxygen to the rest of your organs. Small amounts over a long time will build up the levels of CO bonded hemoglobin in your system a little at a time until you begin to show the effects.

At a minimum, I would buy a CO meter with a digital readout that shows you the concentration of CO in the air and keep it in the kitchen near where you're brewing.

A standard burner and a heat stick is far, far safer.

 

[Owly055]

Be careful with this. Even if the flame looks clean it's more than likely producing more carbon monoxide, probably enough to create dangerous levels of it in your kitchen. I did the same experiment on my own stove, and using a CO meter showed elevated and near dangerous levels of CO within 20 minutes of starting the burner on high, and it had a clean blue flame that left no soot behind. CO poisoning is no joke, as it has a cumulative effect; CO bonds to the hemoglobin in your blood more readily than oxygen and doesn't let go, which reduces your blood's capability to carry oxygen to the rest of your organs. Small amounts over a long time will build up the levels of CO bonded hemoglobin in your system a little at a time until you begin to show the effects.

At a minimum, I would buy a CO meter with a digital readout that shows you the concentration of CO in the air and keep it in the kitchen near where you're brewing.

A standard burner and a heat stick is far, far safer.

I'll do that................. I had a "near death experience" a couple of years ago with CO when I was working. I didn't realize that something was wrong with me until someone walked in and began helping me and I found I had labored breathing and other symptoms I recognized. He saved my life simply by showing up at the right time. He didn't realize I had a problem, but I did. I didn't realize what had happened until several hours later.
I had a similar experience many years ago, when CO detectors weren't readily available. Recovery is fairly rapid......for me at least. I hung CO button designed for aircraft use in my shop after that, and quickly found that I am exposed to a great deal of CO ... It rapidly turned black on a normal day, and generally proved useless. Unfortunately the PPM they consider dangerous are far below what makes sense in terms of real life exposure.

H.W.

 

[sablesurfer]

Avoids stuck

Hmmm...I have the false bottom, and my BIAB is at full volume for what I want to start my boil with. So not sure how you are going with a higher volume water.