Inverted HERMS? (iHerms)

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I've been toying with the idea of doing what I call an Inverted HERMS (iHERMS? lol).


You recirculate your mash liquid but it does not go though the HLT. It just recirculates from the bottom of the MLT to the top. There is a coil in the MLT that hot water is pumped through.

My theory here is that it would provide more equal heating of the mash and allow for better step ups in temperature in the mash.

It would require an additional pump for the hot water, but not necessarily food grade if the water was heated separately from your HLT. (If using your HLT as the water source then you would want a food grade pump).

Has anyone done this? Thoughts?

I probably won't get around to doing this for a while. I've already spent to much on things lately.
 

The Pol

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I will have to disagree with the thinking that this will somehow allow faster step ups in the MLT. How? You are still heating the same ammount of liquid arent you. The liquid in the HLT and MLT? You are still using the same heat source arent you? Thusly... the same BTU, same volume, same time.

As for more uniform heating Id say again, maybe not. Even though you are recirculating the MLT water, you will have a direct source of heat in the MLT, creating relative hot spots near the coil. In a true HERMS, you dont have this, there is no heat source in the MLT, more uniform heating.

So I dont see any real gain, but I do see the expense of another pump.

My thoughts, my .02.
 
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Well, it has been argued that the mash from a HERMS tends to be hotter at the top. The coils won't be any hotter than the water source so I don't really see the difference in relation to a HERMS.

You set the water source at your target temp not above it. This is still a heat exchanger. I didn't say it would necessarily be quicker. Just a more even rise in overall mash temp through out the entire mash.
 

The Pol

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I understand the concept of HERMS... I just figure that if you are pumping at a rate of 1.5 gal/min, you are recirculating the entire mash every 2-3 minutes. If your vessel is insulated at all, the ammount of heat lost from top to bottom in a 2-3 minute period would be minimal. The re-heated mash water entering at the top would be the same as your target temp, as you stated. So, unless it is cooling significantly during its 2-3 minute trip to the bottom of the MLT... I dont see the issue with temp stratification in the MLT with a typical HERMS.

You did state in the OP that youd expect to be able to step temps better... that is what I referred to in my previous post. I presumed better meant faster.
 

The Pol

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Not trying to talk you out of it... I say do it. I dont know that there will be any difference in the quality of the beer, but it definately wont hurt it. I am just the type that doesnt want to buy another piece of equipment unless the cost/benefit ratio is there somewhere.
 
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This is what I'm trying to determine. I've read some pretty valid arguments against using HERMS for step mashes due to the stratification of the mash.

This shouldn't happen with this type of system when raising temps. The entire mash should be rising in temp at pretty much the same time.

Also, besides what I have read, I noticed something the other day when I decided to do a batch sparge for once.

I mashed out at 170. Drained then filled the tun with the sparge water and recirculated for 15 minutes. I didn't stir the mash at all. I used a 180F sparge since I noticed the temp on the tun had dropped to around 165F. (keggle MLT and it was pretty cold out).

The temp on the tun after recirculating for 15 minutes was about 170F. When I stopped recirc and drained the tun I noticed the MLT temp started climbing till it hit close to 180F. There was definitely stratification going on. (Therm is near the bottom of tun). Even though this was aprge water, this should be close to the action of a HERMS when raising temps.

Maybe this is less of an issue with a cooler MLT? I dunno.

I was going to change to a HERMS but I keep reading that they aren't very good for step mashes and I do have some recipes I like to do step mashes with.

BTW, I'm not declaring this to be the best or better system. I'm just theorizing and asking for discussion upon the merits of such a system; particularly in regards to step mashing. Is it worth the expense of another pump? Would it really work any better?

(note: above temps are approximate. I forgot to write them down, and I'm going from memory.)
 

The Pol

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#1... HERMS is horrible for step mashing... there is no way to make it work. Since you cannot heat the wort in excess of the target temp, it takes forever, I have a special spreadsheet made for my system so that I can couple recirculating with infusion mashing all from the same HLT water.

#2... When I mash out, I recirculate for about 20 minutes (this is the only time I use HERMS to step up the mash temp)... after 20 minutes I dont see any stratification in the temps in the cooler.

#3... I DO think that coolers make a huge difference. I mean they have lids and an inch of dense insulation on the sides and bottom. There is so much heat lost with SS and aluminum kettles, that compeltely changes the variables. If it is 40F outside, my cooler shell is 40F... there is no heat loss. A SS kettle wall would be about the same temp as the mash... A LOT of heat loss.
 

BierMuncher

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#4....I've no idea what you guys are talking about...but it sounds like fun.


#E....I like bullet pointing for emphasis too...


#6....What were we talking about????
 

The Pol

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#4....I've no idea what you guys are talking about...but it sounds like fun.


#E....I like bullet pointing for emphasis too...


#6....What were we talking about????

Psst, someone is drinking.
 
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Psst, someone is drinking.
No, that's just Biermuncher's educated input into the discussion.



... Nah, he's druk. :D

Pol, I'll have to give this some more thought. I don't really want to get another pump, and I do want to be able to step mash. My Keggles are all insulated but are no where near as heat keeping as a cooler.

I've had two scorches trying to step up with a direct fired RIMS. I don't like the idea of overheating the wort (standard RIMS). Hmm... Somehow there has to be another way..
 

The Pol

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I have played with about everything... and there are only a few ways to effectively step IMHO.

Infusion (which is what my self made spreadsheets allow, it is tricky while also running the HERMS)

Decoction (which is sorta like Infusion)

Direct Fire

There is just no way to efficiently, passively heat your MLT. Youd need an element and pump capable of running a 1' ID hose at 6 gal/min while heating the water through the HEX to target temp in one pass. Serious. Our pewny hoses and flow rates are just not capable, there is not enough flow and thermal transfer.
 

The Pol

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True true... but I dont feel like I can set that and forget that...
 

The Pol

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That is pretty much what I have, isnt it? There is a reason... there is.
 

FlyGuy

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I'll put a vote in for steam. I am still building my SIRMS (steam injected recirculating mash system). The benefits of steam are huge -- you can use a cooler, you can heat the mash with all the benefits of direct fire/RIMS, but no issues with scorching (at all) or overshoots (when using a cooler MLT), and it has the potential to be automated (just need a steam valve wired to a temp controller). Easy, simple to build, inexpensive.

I probably won't automate it for a while, but everything else is working well with some basic equipment: March 809 for recirc, 6 gal pressure cooker for steam generation, 10 gal Rubbermaid MLT. The entire system cost me about $350.

And the added benefit of the steam system is that once the mash is done, you can rinse off the steam manifold and throw it in the kettle to HUGELY speed up time to boil (i.e. direct fire the kettle AND inject steam, essentially transferring the heat from two burners simultaneously into the kettle with no more risk of scorching than with just one burner).

As soon as my stand is (finally) built, I'll post some photos of the system. It is as simple as one can get, but has some significant advantages over RIMS and HERMS systems, IMHO.
 
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I'll put a vote in for steam. I am still building my SIRMS (steam injected recirculating mash system). The benefits of steam are huge -- you can use a cooler, you can heat the mash with all the benefits of direct fire/RIMS, but no issues with scorching (at all) or overshoots (when using a cooler MLT), and it has the potential to be automated (just need a steam valve wired to a temp controller). Easy, simple to build, inexpensive.

I probably won't automate it for a while, but everything else is working well with some basic equipment: March 809 for recirc, 6 gal pressure cooker for steam generation, 10 gal Rubbermaid MLT. The entire system cost me about $350.

And the added benefit of the steam system is that once the mash is done, you can rinse off the steam manifold and throw it in the kettle to HUGELY speed up time to boil (i.e. direct fire the kettle AND inject steam, essentially transferring the heat from two burners simultaneously into the kettle with no more risk of scorching than with just one burner).

As soon as my stand is (finally) built, I'll post some photos of the system. It is as simple as one can get, but has some significant advantages over RIMS and HERMS systems, IMHO.
Hey can you PM me with what you used for steam generation? And from where in Canada you got it?
 

Yorg

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I have automated with Steam.
Used a corny as the generator and PID as controller.

Issue is getting even heating (remembering this is about not using a wand and stirring, but setting and forgetting with a manifold).

It also makes me nervous - though a big pressure cooker of around 20qrts wouldn't since it's designed for it.

I am going back to HERMS - will "overheat" my wort for steps, which is what a direct fired system does at the base of your mash tun.

I would like to see you do your iHERMS, and put a couple of themometers in different locations to establish heat distribution performance. I thought of doing this too, but an extra pump... Also, I can't imagine why you would get stratification in a regular HERMS in a cooler, whilst continuously circulating, and no more than a plain vanilla infusion system if not continuously circulating ( which I don't know of anyone doing).
Also, if HERMS is not useful for stepping, why bother with it over a regular infusion mash in a cooler?
 

The Pol

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HERMS is impossible to step with, in my HERMS experience and through my research on the subject.

It is useful because:

You can tweak your mash temps to within .5F

Less worry of stirking too hot or too cold

Uniform temps throughout the mash because if the recirc.

Super clear wort and great filter bed for fly spargers because of the recirc.

HERMS has many benefits, but step mashing never has been one. Id never want to go back to a single infusion cooler MLT system. The HERMS is suitable for a mash out... this is not time sensitive since conversion is complete anyhow IMHO.

HERMS has its place in coolers
 

Catt22

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FWIW, I'm using a direct fired RIMS without scorching problems including step mashes. Mash outs are also no problem. I recirc continuously through the entire mash. I currently have a CAP that I brewed with this system that I'm sending in to the AHC. I'm almost certain it will make it to the second round.
 

Cape Brewing

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Infusion (which is what my self made spreadsheets allow, it is tricky while also running the HERMS)
Why would an infusion be tricky while running the HERMS?

Are you thinking about simply having to shut down the circ while you bring the infusion volume up to temp?

I guess I'm curious about that since I can't imagine the temp in your MT is going to rise that much in the short period of time it's going to take to step up your infusion temp.

Just to illustrate with completely made up numbers (so please don't Beersmith it and tell me my numbers are off)

I'm doing a protein rest with 8 gallons of 125 degree water.... and I want to step that up to 152... Beersmith tells me I need... I dunno... 3 gallons of 185 degree water...

I have a 25 ft 1/2 coil suspended in my HLT and my mash circs continuously from the MT. I have two 32-tip jet burners on Nat. gas and they toss off HEAT.

I could probably bring my HLT up from 125 to 185 in.. I dunno... 10 minutes?

I guess the theory would be that I would be turning over my MT volume during that ten minutes at least once and passing it through rising temp... but I don't see how that would hurt things as you would only have it at this elevated temp for a split second and then it would return tot he MT and very slowly raise overall temp...

... and then when I hit 185 in my HLT... I do the infusion.

Am I off in left field somewhere??
 

The Pol

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It is tricky, trust me.

Heating the initial strike in the HLT

Strike and rest at 125F

Now I have to heat the HLT to 190 or so for my infusion step (this takes 20 min)

So I completely 20 min. rest at 125F and then infuse with the proper volume to hit 155F (just an example)

Now I have to get my HLT DOWN to 158F or so, so that I can recirc with the HERMS

I need to infuse the HLT with a measured qty and temp of water to cool it from 190F to 158F to begin the recirc for the sacc. rest.

That gets complicated, computing temps, volumes and heating times for the HLT so that after the protien rest the HLT is ready to do the infusion into the MLT. If it takes 40 minutes, you are screwed sorta.

It isnt easy, trust me, I built it and created all the calculations for the spreadsheets.


Once your HLT is up to 185F... you have to cool it to do a recirc, dont you?

Also, you are using gas to heat, that is TOTALLY different than an electric system. How many BTUs do you think even a 5500W element puts out? About 10% of your gas burner, maybe... so therefore you and I are talking about totally didfferent beasts.
 

Cape Brewing

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I can totally dig it.....

yeah, i don't see it as being a big deal for me (although I ADMIT... I haven't done it yet)

To get my HLT up to the proper infusion temp should be very quick and easy given Beersmith's help to calc volume and temp.

And then, to your point, when I have to get the HLT back down to temp to circ... all I would do is flip a switch and top off with fresh 50degree or so water... I don't think I would even need a calc for that... flip a switch... watch it drop down to... 160ish... stop... give it a stir... and then just keep adding a little at a time until I'm whatever my mash temp is and if I overshoot on the cold side, my PID controlled burner will kick on and hit the temp in two seconds... ...

It's a little more fiddling with stuff but I don't think it would be a huge burden.
 

The Pol

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See, I have to BUY every drop of water I use... so my water calculations are very precise throughout the brewing regime.

I calculate the exact qty and temp. to get my HLT down to recirc temp, and all of that water in th HLT is then used to sparge, when it is gone, and the MLT is dry, I have reached my pre-boil volume.
 

Cape Brewing

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yuck...

I guess I'm lucky in that regard. I'm certainly not wasteful with my water but I don't have to be that precise.

My garden hose plugs into a quick connect at one end and I have filtered water to any part of the rig with a switch flip....
 

The Pol

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Yah, our water here is borderline illegal for consumption... so I buy water. Not a big deal, but I am a very precise person.
 

Cape Brewing

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yup.. I'm lucky... we have great water and like I was saying, I don't waste it... anything left in my HLT post-sparge is boiled and washed through the system to clean it. (I'm hard-plumbed from beginning to end)

sorry to drift off-topic
 

The Pol

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Meh, screw topics...

I am totally silicone plumbed, but I do get a nice hot PBW wash through the rig and hoses while I am boiling.

I am brewing this coming weekend, will have a video up detailing it.
 

Cape Brewing

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I have two batches this weekend... one Friday and one Sunday. I've been saying I'm going to do "grain to glass" pics... maybe that'll be this weekend.
 

FlyGuy

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I have automated with Steam.
Used a corny as the generator and PID as controller.

Issue is getting even heating (remembering this is about not using a wand and stirring, but setting and forgetting with a manifold).
What method are you using for recirculation? I don't have a PID or temp controller running yet, but I have had no problem hitting temps with steam injection and a pump to continuously recirc the wort. Could it be that you aren't getting enough flow, or perhaps, you are getting some channelizing in the mash tun and not pulling the wort evenly across the steam manifold?

Lotsa good discussion in this thread, BTW. :mug:
 
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I don't mind if the topic drifts.

Cat22, do you stir during step ups with your direct fired RIMS?

I used to stir when I did not have a recirculating system and did not scorch. Twice now with a recirculating system and not stirring, I ended up scorching. The first time was a flow problem, I fixed that. The second time I ended up with foaming in the line during heating (foaming seemed worse at higer temps than low) which resulted in cavitation in the pump which slowed down my recirculation and resulted in a slight scorch.

I still think my idea is sound above, but with the cost of a second pump it would probably be better to go to steam.
 

Catt22

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Denny,

No, I don't stir the mash at all after the initial mash in. The exception would be if I observe the beginnings of a stuck mash or any problem with the recirc flow rate.

I agree that your basic concept is sound, but I don't have any experience with a HERMS at all so my opinion on this isn't worth a whole lot.

I also find using steam an interesting innovation. I'm not sold on waving a steam wand around in the mash though. You still need to stir the mash to distribute the heat evenly. I'm thinking maybe a hybrid design combining a RIMS with steam injection. The idea being that the continuous recirculation would eliminate the need to stir while simultaneously injecting steam for stepping up the temps.
 

kladue

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FWIW I have been using steam injected into circulating wort for step mashes since 2003 and have come up with a fairly easy to operate system albiet unique. The down side to steam injection into wort is that it requires nearly constant temperature monitoring and adjustment of steam flow, but step time from 130 to 148 takes 11 minutes with a 12 Lb grain bill.
 

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HERMS is impossible to step with
I'm afraid I have to disagree with this.

HERMS has many benefits, but step mashing never has been one. Id never want to go back to a single infusion cooler MLT system. The HERMS is suitable for a mash out... this is not time sensitive since conversion is complete anyhow IMHO.
If you use a seperate waterbath, rather than the HLT, for your heat exchanger it is absolutely possible to conduct a step mash with a HERMS system.

I have a heat exchanger made from a 12 inch length of 6 inch diameter copper pipe, sealed at one end containing a copper coil to recirculate the wort through. Heat is applied with a 2.4 kw element that I control with a PID controller.

With this setup I can increase my mash from 50C to 66C in 10 minutes. This is because the water bath only holds about 4 litres.

I believe this is quick enough to consider step mashes feasible.

It is still a HERMS as the heat is applied indirectly via a water bath.

Of course, if you install your HERMS coil in your HLT any temperature rises will take a long time due to the amount of water in the HLT. In which case the comments from Pol are correct.

/Phil.
 

missing link

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I'm afraid I have to disagree with this.



If you use a seperate waterbath, rather than the HLT, for your heat exchanger it is absolutely possible to conduct a step mash with a HERMS system.

I have a heat exchanger made from a 12 inch length of 6 inch diameter copper pipe, sealed at one end containing a copper coil to recirculate the wort through. Heat is applied with a 2.4 kw element that I control with a PID controller.

With this setup I can increase my mash from 50C to 66C in 10 minutes. This is because the water bath only holds about 4 litres.

I believe this is quick enough to consider step mashes feasible.

It is still a HERMS as the heat is applied indirectly via a water bath.

Of course, if you install your HERMS coil in your HLT any temperature rises will take a long time due to the amount of water in the HLT. In which case the comments from Pol are correct.

/Phil.
The same would hold true for a RIMS system with a very large heating element in a HEX. My system uses a 1500 watt element and on a 5 gallon batch I see about 5 degrees increase as it flows through the HEX. Meaning the output is about 5 degrees warmer than the input. This gives me a rise of 1 or 2 degrees per minute. To slow for step mashes.

However, using a 5500 watt element in slightly larger HEX would allow you to reach your step temp at the outlet of the HEX regardless of the input temp. It would only take 10 minutes or so to turn the entire volume of the mash tun over multiple times and bring the grain up to temp.

I don't brew with step mashes so I have not found a need to try to build something like this. In POL's case he already has the PID and power available to make either version work for him.

Linc
 

The Pol

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FWIW, even if my HLT is at my set point, say 158F... raising my temp in my MLT from 125F to 155F will take MUCH longer than 10 minutes.

In my system it is not the HLT alone that causes such slow heating of the MLT, it is the fact that I am only heating the MLT with 158F water, no overshoot. If my HLT is up to temp prior to starting the recirc. and step up, it helps, but that is only half the battle as I have 6 gallons of thick thermal mass in the MLT that needs to be raised. Changing the temp of a 150F mash with 158F water for example is VERY slow unless you have an incredible flow rate. My rate is about 1.5 gal/min

I am impressed that you can reach those temps so quickly, while not overshooting on your HERMS output temp. Good for you. If I chose to overshoot, Id be able to do it much quicker, but that is not something that I desire doing.

I just wrote a complex set of calculations and placed them in an easy to use spreadsheet for myself and all of the builders of my system. It allows you to precisely calculate the temps, times, quantities etc. of water going into and out of the HLT so that you can STEP INFUSE with that water and recirc as well. This allows for instant temp steps, while still allowing the recirc. capability. This way, regardless of mash size, they get a quick step...

The new $3.26 sight gauges were the last step in making this a no brainier operation.
 

Cape Brewing

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AM I reading things incorrectly or is the real question with all of this aroud people's individual feelings about overshooting on whatever you're usig for your heat exchanger??

What I mean is... it sounds like Pol (and I run my rig the same way) can't really step because of his dislike of heating wort up over his target temp and then adding back into the mash while others don't seem to have a problem with it.

For example... I run a coil through my HLT and then heat the HLT directly to maintain temp in the MT.... I can certainly step up quickly if I jack my HLT up to boiling as opposed to simply raising my HLT to the target temp itself.

... so I guess I'm just tryig to figure out what guys are specifically talking about....
 

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I'm using about a 40 litre mash for a typical brew (but it could be as high as 70 litres) and I wouldn't say I have a particularly fast flow rate. Probably about 5-7 litres per minute.

The beauty of using a small volume water bath is that you can control the temperature of the bath based on the temperature of the wort coming out of it. So, no overshoot. What it says on the PID is the temp of the wort :)

/Phil.
 

The Pol

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I have no idea what I am talking about.... :mug:
 
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