RIMS/HERMS brewers: crush, speed, and manifolds?

Questions for all you RIMS/HERMS brewers (or anyone who recirculates):

-What size crush you using?
-How fast are your recirculating?
-What are you using: braid, false bottom, manifold, etc?

I've been doing RIMS for a few months now. My first few batches were stock BC crush (.039) and a few kit brews (bad crushes). I'd been using a false bottom and putting my grain in a paint strainer bag (it made clean up somewhat easier). So, I started experimenting. One batch I tried "normal" - .039, FB, no-bag - horribly stuck had to babysit it and stir like crazy every 5 minutes. Tried double crushing - same deal. Tried a SS braid - same deal.

So today, I try my FB with a .030 crush - good grief, stuck like cement.

I generally open the valve about 1/4 of the way and then slowly open it up. But some of these have been getting stuck at 1/4 open.

I know I've been changing alot of variable, but the beer has generally turned out well. As cheesy as it is the bag worked for me, it was just a big pain to stir at dough-in.

Thanks in advanced.

What liquor/grist ratio are you using?

Lots of cereal grains (wheat etc.)?

Mash tun arrangement (cooler, keggle, etc.)?

Any other details?

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I use a converted keggle with a false bottom and can recirculate a standard store crush (~0.039) at near full speed (>1gpm) with my march pump. If I am using a lot of wheat, I either need a good protein rest, a decoction, or rice hulls.

Boerderij_Kabouter said:

What liquor/grist ratio are you using?

Lots of cereal grains (wheat etc.)?

Mash tun arrangement (cooler, keggle, etc.)?

Any other details?
.

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Sorry, thought about those after I posted:

-Generally 2qt/pound
-No. Today I had 1/2 lb wheat.
-It's a 10-gallon round cooler.

Fiarly standard stuff I think. My RIMS is a 1.2 inch SS tube with an element. All 1/2 plumbing hardware. Silicone tubing.

Today has been the worst brewday ever for me. Just now starting boil after 3 hours of f!-ing with the mash. Haven't even measured my efficiency yet - I usually average 75%.

Next brew or two, I'll probably just use my paint strainer bag. I never had an issue except for stirring with it. (I did quite a few brew-in-a-bag batches, hence the bag...)

I have no idea.... that's odd.

I'm almost convinced I'm cursed after today's fiasco. The BiaB gods are angry at me for abandoning them... With BiaB, I could crush/double-crush whatever and never get stuck, I just only ever topped out at 75% efficiency. The "normal" (non-rims) batches I did turned out "okay" but that was before I did any water treatment other than removing chlorine and using 5.2.

What kind of false bottom do you have? Could it be collapsing?

It came from B3 - SS. I hadn't thought that it may be collapsing.

FWIW, when I stir it when it gets stuck, it's like almost set-up cement.

Is there water sitting over the top of the grains?

I might be worried about the false bottom collapsing, try collapsing it with nothing in there and how hard it is to do.

Is there any other point in the system a blockage could be occurring?

Boerderij_Kabouter said:

Is there any other point in the system a blockage could be occurring?

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I don't think there is. It runs water at "full blast" just fine, and when I use a bag, I can run it fully open.

Had 3 very frustrating brewdays in a row. sigh....

I just looked at the B3 FB. No way that thing is collapsing....

How does it drain if you let gravity do its thing? Could it be a pump arrangement problem?

I generally let gravity do it's job for the runnings. They are very slow when it's "stuck." Pumps are a possibility. My MLT and HLT feed into a tee that goes into in side of the pump, maybe something wierd with the dynamics there??

It's all about the rice hulls... I have a 10 gal HERMS system that I recirc at full flow... I always keep rice hulls on hand and keep an eye on the flow. If needed I add more until full flow can run uninterrupted. By the time I'm ready to sparge, I have no worries...

I'm using the SS false bottom from NB and love it, all 1/2" fittings and tubing.

I am currently using:

.035" gap on my BC
about 200RPM for the crush
1.5-2.0qt/lb for the mash
False bottom
Recirc at about 3qt/min
No rice hulls

Hmmm. so everyone else seems to have a similar setup to mine, but I get stuck like crazy. Pol, it seems a HERMS would actually be more resistance than my RIMS, but you don't have any issues. BTW, is 3qt/min about 1/4 of the way open? FWIW, I hand crushed my batch yesterday at .030. I'll probably open it up to .035 (or even back to stock) for next batch. I tried rice hulls... I'm cursed I tell ya...

3qt/min is about 1/4 open yes...

FWIW, I crushed @ .030 today with a bag. I'm able to run the recirculation at full open. My bag is large enough for my whole 10 gallon cooler to fit in. So for now, I'm just going to continue doing it this way.

Just to add to this... I recently did a wheat beer.

61% wheat malt

I crushed at .036" at about 200RPM. The wheat kernels were all in about three pieces, crushed nicely.

I did a 2qt/lb mash

Recirculated at 3qt/min. as usual

No stuck mash, no stuck sparge.

I ran my MLT DRY during the sparge as I always do, still, no sticking.

Again this is in a NB SS false bottom.

My setup:

Barley Crusher factory setting (.039)
Recirculating at full speed (I would guess about 2qt/min)
Northern Brewer SS False Bottom in a 10 gallon Rubbermaid cooler

All my plumbing is 3/8" ID Silicone tubing and I run through a 20' 1/4" ID copper coil in the heat exchanger.

I just open the valve on the MT all the way as soon as I mash in, let the pump prime and recirculate full speed. Sometimes the flow is a bit slow in the beginning but it speeds up after 10 minutes or so.

I've only had the HERMS built for the last two batches but I haven't had any issues with grain bed compaction. It's been loose and fluffy at the end.

I'm thinking my weak pump, 3/8" tubing and 1/4" coil actually work in my favor in my HERMS rig. I have a lot higher output resistance on my pump than most people with 1/2" plumping do. The pump creates very little suction and the rate is mostly determined by how fast gravity will feed the wort to it.

Perhaps you could rig up some kind of grant to feed the pump. That way you know if it's the suction of the pump causing compaction.

EvilGnome6 said:

Perhaps you could rig up some kind of grant to feed the pump. That way you know if it's the suction of the pump causing compaction.

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Putting the grains in a bag never clogs. The bag cost me $2 (fabric store). I'll just let it be for now.

bakins said:

Putting the grains in a bag never clogs. The bag cost me $2 (fabric store). I'll just let it be for now.

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Good point. If I ever run into the same issue I'll keep it in mind.