Mash Recirc and grain bed compression

[BandonBrewingCo]

Hi,
I've got a 15G SS Brewtech kettle with false bottom on an induction heater. I've got a 12V pump recircing the mash but it seems to be murdering my conversion effeciency.
So i gave the grain bed a poke and it is very, very compact. Not at all compact enough to stop flow mind you, I'm just worries that some grains arent having enough contact with the water and therefor not releasing all their goodness.
Can I somehow restrict the flow of the dc pump by using ball valves? Or will that mess up the pump?
Thanks in advance

 

[mongoose33]

In what way are you returning the wort to the kettle? A manifold? Just squirting it in?

Have you considered adding rice hulls to the grist? I put in a scoop when I'm concerned about that, a scoop being roughly equivalent to around 1/2 pound of rice hulls. They help to act as a filtering aid so the mash doesn't pack down as tightly and they help filter.

Is your mash too thick? How many gallons of water to how much grain? Is the pH in the right neighborhood?

*************

In answer to your specific question, if you put a ball valve on the output side of the pump you can control the volume.

 

[BandonBrewingCo]

In what way are you returning the wort to the kettle? A manifold? Just squirting it in?

Have you considered adding rice hulls to the grist? I put in a scoop when I'm concerned about that, a scoop being roughly equivalent to around 1/2 pound of rice hulls. They help to act as a filtering aid so the mash doesn't pack down as tightly and they help filter.

Is your mash too thick? How many gallons of water to how much grain? Is the pH in the right neighborhood?

*************

In answer to your specific question, if you put a ball valve on the output side of the pump you can control the volume.

Just have a hose returning to the top of the mash in a whirlpooly way (under the surface but sideways)
I'm doing full vol mash so it's not very thick at all
PH is ok. I've throttled it at return ball valve as per your advice, let's see how it goes!

 

[brewing_clown]

Unrestricted flow can cause too much suction under the grain bed, and compaction. It's fairly standard to throttle the flow with a valve.

I doubt it would hurt the pump too much at all. I have a mash recirculation setup that is generally throttled for the duration of the mash. I haven't experienced any problems. Valve is on the return into the mash.

 

[BandonBrewingCo]

Unrestricted flow can cause too much suction under the grain bed, and compaction. It's fairly standard to throttle the flow with a valve.

I doubt it would hurt the pump too much at all. I have a mash recirculation setup that is generally throttled for the duration of the mash. I haven't experienced any problems. Valve is on the return into the mash.

Good to hear. I suppose I was only concerned for the pump as it gets more high pitched the more I restrict the outflow. Meh, worst case scenario it's a €14 pump.

 

[Dcpcooks]

You should consider flow rate as a guide. You don’t have a meter but you can still use a container to measure how much volume your pumping. You’ll want roughly .75-1.00 gpm of flow. Every system is a bit different but those flow rates should yield good conversion and efficiency while limiting compacting the grain bed. Just grab a pitcher or other container with liter or gallon markings and adjust your valve until you hit a nice even flow of .75gpm. Then you can mark your valve so you can dial it in next brew day.

 

[mongoose33]

I'm working on getting a Herms system set up for me and one concern is how I'm going to return the wort to the mash. I'm thinking of it more in terms of what people do when they fly sparge, with just little trickles of water (with HERMS: wort) going on top of the mash as the wort is drawn away at the bottom.

I'm looking at this in terms of LODO brewing, such that I want the wort returned to the mash under a mash cap. One approach is to use LocLine nozzles to distribute the wort back to the mash.

I'm not necessarily advocating locline here--and not NOT advocating it--just that you can see, with all those little nozzles, you can distribute the returning wort all over the mash, not in a single place where it might create channeling.

There are other ways you could create a manifold to distribute returning wort--perhaps PVC pipe, perhaps silicone tubing, perhaps other ways of just dribbling it onto the top of the wort rather than squirting it and creating a pattern of drainage that doesn't allow for full conversion.

 

[BandonBrewingCo]

You should consider flow rate as a guide. You don’t have a meter but you can still use a container to measure how much volume your pumping. You’ll want roughly .75-1.00 gpm of flow. Every system is a bit different but those flow rates should yield good conversion and efficiency while limiting compacting the grain bed. Just grab a pitcher or other container with liter or gallon markings and adjust your valve until you hit a nice even flow of .75gpm. Then you can mark your valve so you can dial it in next brew day.

Will do, very helpful, thank you.(note to self ~3L/min = 1L per 20sec)

I'm working on getting a Herms system set up for me and one concern is how I'm going to return the wort to the mash. I'm thinking of it more in terms of what people do when they fly sparge, with just little trickles of water (with HERMS: wort) going on top of the mash as the wort is drawn away at the bottom.

I'm looking at this in terms of LODO brewing, such that I want the wort returned to the mash under a mash cap. One approach is to use LocLine nozzles to distribute the wort back to the mash.

I'm not necessarily advocating locline here--and not NOT advocating it--just that you can see, with all those little nozzles, you can distribute the returning wort all over the mash, not in a single place where it might create channeling.

There are other ways you could create a manifold to distribute returning wort--perhaps PVC pipe, perhaps silicone tubing, perhaps other ways of just dribbling it onto the top of the wort rather than squirting it and creating a pattern of drainage that doesn't allow for full conversion.

See, I just noticed that, the whirlpool created a mounded grain bed... grrr. Will have to think about some sort of manifold alright, shouldn't be too hard. Locline is expensive here in Europe, it'll most likely be some sort of pvc solution. Essentially a rip off off the SS Brewtech one

 

[Dcpcooks]

I use the ss unit pictured above. Works nicely without creating the low spots you’ll get from the whirlpool method. I do just let it whirlpool for the bulk of the mash. I usually give the top third of the grain bed a stir at 40 min and let it settle for a bit then I install the manifold and recirc with that for the end and the fly sparge.

 

[day_trippr]

fwiw, I run an autosparge feeding a 3/8" silicone tube suspended atop the mash with an SS float ball keeping it from sinking. I set the autosparge to keep just about two inches of wort above the grain bed and the return from the tube is near the top. I recirculate at roughly 2 gallons per minute once the bed has set.

The classic sparge rings/sprinklers/dribblers have two issues: they drop the wort through the air, and they have small holes that can get plugged.
The first one, for me, is a show-stopper, period. I'm doing as much as I can to avoid aerating wort before yeast is pitched, so that's right out...

Cheers!

 

[Smellyglove]

I brew the same way as TS, no sparge with a herms. Pump needs to be throttled, no need for rice hulls, and I'm returning the wort to below the surface using a hose from the herms ehich ends up in a barbed 1/2" male NPT which I've stuck an end cap onto and slitted the endcap so the wort will flow out in a more or less quite uniform way in a horizontal manner beneath the surface.

Could be done more fancy but I don't want to do to much extra since the return hose also is long though to reach into the boil kettle so when cleaning I stick it into the BK while recirculating hot water.

 

[BandonBrewingCo]

Ya it seems that me recircing too fast was causing the whirlpooling and mounded grainbed issues. Next brew I'll try the 3L/min rate and if it's still causing issues, then I'll look into a manifold. How did you cap the silicone tube?

 

[mongoose33]

I brew the same way as TS, no sparge with a herms. Pump needs to be throttled, no need for rice hulls, and I'm returning the wort to below the surface using a hose from the herms ehich ends up in a barbed 1/2" male NPT which I've stuck an end cap onto and slitted the endcap so the wort will flow out in a more or less quite uniform way in a horizontal manner beneath the surface.

Could be done more fancy but I don't want to do to much extra since the return hose also is long though to reach into the boil kettle so when cleaning I stick it into the BK while recirculating hot water.

Would you have a pic of this? I'm having a little trouble visualizing it...

 

[NeoBrew]

One other suggestion. I find that throttling the valve low or off when you first start recirculating is important. When I first got set up for recirculating I would start out full blast and then valve down. In those first few moments the damage was done and the bed was compacted. For some reason after that happened even stopping and stirring the mash wouldn't fix it.

I have a magnetic drive pump and typically close the valve 100% when I start and then open it slowly a little bit to get the bed set. I don't believe magnetic drive pumps will suffer from running when wort can't flow. (But I'm not engineer!)

 

[daveMN]

One other suggestion. I find that throttling the valve low or off when you first start recirculating is important. When I first got set up for recirculating I would start out full blast and then valve down. In those first few moments the damage was done and the bed was compacted. For some reason after that happened even stopping and stirring the mash wouldn't fix it.

I have a magnetic drive pump and typically close the valve 100% when I start and then open it slowly a little bit to get the bed set. I don't believe magnetic drive pumps will suffer from running when wort can't flow. (But I'm not engineer!)

I have a March pump and do the same. I'll start out low flow and open up the ball valve to full over about 5-10 minutes. When I was staying low flow through the mash, I was getting temperature stratification, as much as 10 degrees from my locline at the top and the temp probe at the bottom. I have an E-BIAB setup, for a frame of reference.

 

[ancientmariner52]

I am an engineer. Steam turbine and ship propulsion type, not college degree type. We always started centrifugal pumps with the outlet valve shut. Just don't leave it shut long, as the impeller is doing work on the fluid, and that work turns to heat if it can't turn to flow. This applies to a 1/20 hp wort pump as well as an 1100hp steam driven boiler feed pump.

Mount your pump as low as possible, to get maximum suction head. (Don't blame me, I didn't invent these terms.) You can open the outlet valve to burp any air, but shut it before starting. Never run a pump dry.

Cavitation happens when liquid starts to boil in the pump body, due to low suction head pressure. Pumps don't work on steam. Throttle down the outlet, increase the suction head, or slow the pump down. My preference is to slow the pump. I hate trying to throttle a ball valve, globe valves are much better for throttling.

Sorry for the disorganized knowledge dump, hope it is useful to someone.

 

[day_trippr]

The mag pumps typically used in brewing decouple the impeller from the motor if the outlet is throttled/closed.
No steam happening here - indeed, if there's any thermal rise at all it would be friction from a wetted thrust washer, which seems likely to be tiny...

Cheers!

 

[ancientmariner52]

The mag pumps typically used in brewing decouple the impeller from the motor if the outlet is throttled/closed.
No steam happening here - indeed, if there's any thermal rise at all it would be friction from a wetted thrust washer, which seems likely to be tiny...

Cheers!

I always figured that was more to protect the motor if the impeller got jammed and to eliminate the need for a rotating seal, but, yeah, I get your point. Still, good engineering practices, right? Why would you need to run a wort pump against a shutoff head for more than a moment or two? Any pump we ran with the discharge closed for any length of time had a recirc line.

 

[day_trippr]

Well, I never run against a fully closed outlet valve - no reason to. But when I first start up the mash pump after dough-in and sneak up to recirculation speed, that valve spends the next ~10 minutes going from ~15% to maybe ~50% to get to around 2 gallons per minute.
I'm sure the rotor is slipping through all that but that's what it was designed to do, and the pumps never seems to mind.

Recirculating flow controls are required for positive displacement pumps.
A mag pump is not one of those...

Cheers!

 

[ancientmariner52]

I agree, that works fine. I prefer using digital electronic speed control, so I can easily repeat a previous setting.

As far as recircing, if you are running a main feed pump in standby for hours on end during an underway replenishment, you bloody well better have a recirc line! But that hardly applies to a mag drive wort pump, so I agree there also.

 

[Dog House Brew]

I'm working on getting a Herms system set up for me and one concern is how I'm going to return the wort to the mash. I'm thinking of it more in terms of what people do when they fly sparge, with just little trickles of water (with HERMS: wort) going on top of the mash as the wort is drawn away at the bottom.

I'm looking at this in terms of LODO brewing, such that I want the wort returned to the mash under a mash cap. One approach is to use LocLine nozzles to distribute the wort back to the mash.

I'm not necessarily advocating locline here--and not NOT advocating it--just that you can see, with all those little nozzles, you can distribute the returning wort all over the mash, not in a single place where it might create channeling.

There are other ways you could create a manifold to distribute returning wort--perhaps PVC pipe, perhaps silicone tubing, perhaps other ways of just dribbling it onto the top of the wort rather than squirting it and creating a pattern of drainage that doesn't allow for full conversion.

I had used a manifold with holes mounted to my cooler lid. Sprinkling wort in practice sounded great. I would open the lid and watch thinking about how awesome it was. Then LODO comes waking through the door. I have had trouble with my beers lasting in the keg. I know partly it came from the aeration that came from my return manifold. I just got a new Extreme Marine. I received Locline from BrewHardware.
I should be able to return it under the cap, and be able to open the lid w/o a floppy hose. What ever you decide, I wouldn’t recommend the lid manifold. Just my $.02

 

[mongoose33]

I had used a manifold with holes mounted to my cooler lid. Sprinkling wort in practice sounded great. I would open the lid and watch thinking about how awesome it was. Then LODO comes waking through the door. I have had trouble with my beers lasting in the keg. I know partly it came from the aeration that came from my return manifold. I just got a new Extreme Marine. I received Locline from BrewHardware.
I should be able to return it under the cap, and be able to open the lid w/o a floppy hose. What ever you decide, I wouldn’t recommend the lid manifold. Just my $.02

I had to look up an "extreme marine."

I've been going around and around about this. A HERMS system sounds great in theory. What I don't have is an easy way to keep the HERMS tank heated. Then there's the return manifold, and trying to keep from getting O2 in the system.

If I had a lot of money and was starting from scratch....but no.

Below is a pic of a mash cap I'm using to cap a mash tun. It's 1" foamboard covered by aluminum and then saran wrap. It works pretty darned well. I put a handle on it so I could pick it up out of the cooler.

I've thought about how to add a manifold to that. It's nice because it's foamboard and it insulates as well as caps the top of the mash. But here's the thing: I can usually do pretty well with my conversions. Maintaining temp, provided I get it where it's supposed to be at the outset, is not difficult. All I need do is stir the mash a couple times, and I'm golden.

So, how do I stir that mash without introducing O2 to the mash? A HERMS sounds like an ideal method, but it's complicated, involves more equipment, more cost. Best part is being able to dial in the temp.

So I'm thinking hard about this: Some sort of stir-rod or paddle or something whose handle rises up through the center of the foam board. I could hold the foam board down with one hand, turn the handle and stir with the other, and I'd never have to lift the mash cap to do it.

I've included a pic of what I think that could look like (I'm not an artist, but I hope it's clear). Seems to me this would be far easier than HERMS. All I need do now is figure it out.

 

[Dog House Brew]

I have a 3 tier structure. My HERMS HLT you can see in my avatar. It was great in theory. My rise rate is slow. I quit using it, but with the new cooler I’m going to try it with a similar mash cap like yours. Maybe it will help.

 

[mongoose33]

I have a 3 tier structure. My HERMS HLT you can see in my avatar. It was great in theory. My rise rate is slow. I quit using it, but with the new cooler I’m going to try it with a similar mash cap like yours. Maybe it will help.

I wish I knew what if any negatives there would be in using that foamboard directly in contact w/ the mash. I covered it with Saran Wrap which is inert at these temps, foil first, then it worked pretty well.

I went to BIAB for about a year; previously I'd put my Cube mash tun on a reptile seed mat which would supply a little warmth on the bottom of the cooler, and reduce at least one side from leaking heat. Along with wrapping it, it seemed to work at holding temp.

I've also thought about making an insulated box inside which the mash tun could sit. Foamboard would do that, I think.

And as long as I could find a way to stir without exposing the wort to air, I think I'd make a HERMS system moot.

 

[Dog House Brew]

Wilser is sending me a BIAB. I’ll have it for the next brew. Thinking recirculating HERMS, no sparge. Making a lot of changes, looking forward to learning a system over again. Made a stainless manifold to go under the bag, thought it would extract better. We will see, it has to be better than pounding my mash with 02 like before.

 

[Snarkley]

Ditto, you need a valve on the output. On recirculating, I just dump the line back into the top of the mash tun. Adjust the flow so there is an inch of water on top of the grain. The Keggle yielded 91% efficiency on last Sunday’s batch.

 

[Blazinlow86]

omit

 

[Blazinlow86]

omit

 

[brewbama]

I had to look up an "extreme marine." [emoji4]

I've been going around and around about this. A HERMS system sounds great in theory. What I don't have is an easy way to keep the HERMS tank heated. Then there's the return manifold, and trying to keep from getting O2 in the system.

If I had a lot of money and was starting from scratch....but no.

Below is a pic of a mash cap I'm using to cap a mash tun. It's 1" foamboard covered by aluminum and then saran wrap. It works pretty darned well. I put a handle on it so I could pick it up out of the cooler.

I've thought about how to add a manifold to that. It's nice because it's foamboard and it insulates as well as caps the top of the mash. But here's the thing: I can usually do pretty well with my conversions. Maintaining temp, provided I get it where it's supposed to be at the outset, is not difficult. All I need do is stir the mash a couple times, and I'm golden.

So, how do I stir that mash without introducing O2 to the mash? A HERMS sounds like an ideal method, but it's complicated, involves more equipment, more cost. Best part is being able to dial in the temp.

So I'm thinking hard about this: Some sort of stir-rod or paddle or something whose handle rises up through the center of the foam board. I could hold the foam board down with one hand, turn the handle and stir with the other, and I'd never have to lift the mash cap to do it.

I've included a pic of what I think that could look like (I'm not an artist, but I hope it's clear). Seems to me this would be far easier than HERMS. All I need do now is figure it out. [emoji4]

View attachment 557741 View attachment 557742

Your idea reminds me of the mash rakes I’ve seen in industrialized mash tuns. Should work great. Put an ice cream maker motor on it so you don’t have to turn it. You could use the dasher, too. I think I’ve seen a You Tube video of a Homebrew mash rake.

 

[Smellyglove]

Would you have a pic of this? I'm having a little trouble visualizing it...

Sorry, I did catch your reply but forgot to answer it. I'd say nevermind that setup as I've done something even simpler now. I just return my wort through some piping which ends up in a male 1/2" way below the surface, horizontally. The stream of wort hits the side wall of the mash tun with enough force to distribute it inside the mash tun, beneath the surface. I see close to 0 movement at the surface.

I have three different lengths of piping which I attach to an elbow which is connected to a triclamp (which in turn connects to the inlet) to accommodate the different wort levels after I've seen the numbers for how high the wort-level will be in my software.

 

[TennBrewer]

I'm doing 5 gallon batches in an eBIAB system with recirculation. The wort is returned to the grain bed through a tube with holes along it from top to bottom. It seems that when wort is streamed out these holes several inches above the grain bed it oxidizes the wort and gets a bad off-flavor. Do I need to keep the recirculated wort returning below the surface?

 

[mongoose33]

I'm doing 5 gallon batches in an eBIAB system with recirculation. The wort is returned to the grain bed through a tube with holes along it from top to bottom. It seems that when wort is streamed out these holes several inches above the grain bed it oxidizes the wort and gets a bad off-flavor. Do I need to keep the recirculated wort returning below the surface?

That's what I do with mine.

 

[whovous]

I'm doing 5 gallon batches in an eBIAB system with recirculation. The wort is returned to the grain bed through a tube with holes along it from top to bottom. It seems that when wort is streamed out these holes several inches above the grain bed it oxidizes the wort and gets a bad off-flavor. Do I need to keep the recirculated wort returning below the surface?

It can be a bit of a hassle to get the tube to stay under water, but it is definitely doable. I'm assuming you use the same blue and orange snap together contraption that I use.