RIMS vs HERMS vs Recirculating Direct Heating

CornyKegs 728
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RIMS vs HERMS vs Recirculating Direct Heating. I don’t follow what you mean...?
 
They're all the same honestly. No one is better than the other. Also not sure what you mean by Recirculating Direct Heating. Do you mean Kettle Rims? Or do you mean element in mash kettle like BIAB? Seriously no one system is better than the other. They're just different ways to accomplish the same thing, and they all accomplish the same thing.
 
I’ve got recirc direct heat but would probably go with rims if starting over. The rims means a bit more wiring in the controller but avoids need for solenoid valve and either pilot (that’s what I’d do) or ignighter. Rims then gives you ability to use your controller in PID mode where it can decide percent on vs direct fire forces it o work in dummy mode where it just says on and off.
 
I’d add I can see theoretical advantages from herms regarding less potential for wort scorching vs other two but suspect it is slower to move from step to step and the control algorithm is not as intuitive to me. Plus more equipment and a full wet mash bed at end of lautering.
 
Recirculating Direct Hearing is BIAB type of application. Maybe I’m using the wrong words. Typically I see devices and processes and forget the names, but remember exactly how they work.
 
A metaphor I've heard used to compare RIMS to HERMS is: A HERMS system is like a school bus, big and safe but can't turn or stop quickly. A RIMS system is like a sports car, fast and maneuverable, but more likely to slam into a telephone pole.

HERMS systems are great in that there is little risk. The downside is, based on your particular setup, it can take time to make temp changes, so for step mashing, mashing out, etc. they can certainly do that, but they don't do it as quickly as your typical RIMS system. And while RIMS can make those changes quickly there is the possibility of scorching wort and/or having a stuck mash and really burning the **** out of your wort or burning out your heating element if you don't have safeguards in place.

At the end of the day both can be fantastic and make great beer. A good HERMS brewery is better than a bad RIMS brewery and a good RIMS brewery is better than a bad HERMS brewery.

Direct fire recirculating mash seems like the most work and the biggest room for error.
 
Blazinlow86 said:
Are you talking about biab or 2/3/8vessles? 1g batches or 50g batches..... What's better a ford focus or a f250?
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Concerning 15-30 gal biab for direct fire recirculating, 2 kettle 15-30 gal for RIMs, 3 kettle 15-30 gal for Herms. The best system and why.
 
kevin58 said:
I think it was Randy Mosher who said that homebrewers spend far too much time chasing down the right system, method or piece of equipment when in reality, there is no right way to make beer.
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With all due respect to Mosher, I don’t agree. I do think it is an unrealistic ideal to say there is one right way, but my strong belief is there are certain practices and procedures that yield significantly improved quality/consistency and represent an approach toward the best outcomes possible. I guess I’m saying that statement infers you can be haphazard and it doesn’t matter - and that’s plain false.

We definitely spend far too much time chasing down our systems - that’s what you do with hobbies you love! If this was just about ethanol, heck... a jug of juice, a handful of raisins, and a packet of bread yeast and you’re good to go.
 
Ok now that I pushed the soapbox back under the bed... the RIMs vs. HERMs discussion gets hashed about quite a bit on this forum and in other debate arenas. This is akin to the Coke vs. Pepsi debate... there will never be a clear winner.

That said, my VERY strong preference is RIMs. The car analogy above is well stated... you do need to have appropriate controls to manage RIMs, but once properly implemented, RIMs is far superior, IMO. Simply stated, you heat liquid, rather than heating liquid to heat liquid. With RIMs, you can step faster, mashout faster, have fairly direct temperature control, and aren’t bound to an HLT’s requirements (re-filling after strike, maintaining volume, tying a pump up in water recirculating, etc.

I personally use a high/low power arrangement in my RIMs, so I can heat my strike water in the MLT (rather than in an HLT).
 
RobbieOByrne said:
So which is better?
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HA HA you might as well be asking what the best beer is...

My vote is also for rims hands down, Ive had and used both.

I think of herms as an old hot water tank and rims more like a tankless water heater. one has much faster reaction time and temps can be brought up or down quickly as well as stepped..
 
sicktght311 said:
They're all the same honestly. No one is better than the other. Also not sure what you mean by Recirculating Direct Heating. Do you mean Kettle Rims? Or do you mean element in mash kettle like BIAB? Seriously no one system is better than the other. They're just different ways to accomplish the same thing, and they all accomplish the same thing.
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They definitely are not the same... an old air cooled beetle will get you cross country just as a lexus would but they each have thier advantages and disadvantages performance wise. depending on a persons system and priorities one could be a better choice than the other. For example for a person who wants to step mash... Rims has the large advantage. and if the rims is designed and built correctly there is zero realistic danger of scorching.. if its thrown together with the wrong components its a real possibilty, but then again there are many herms out there not performing right either with no HLT recirculation to keep consistent temps around the coils... In reality these types of systems are only as good as thier implimentation. For some people I really believe a cooler is the best choice. And often those are the people who comment about how poorly herms or rims worked for them..
 
BLUF is it comes down to a personal preference and what you want in your system..each to his/her own...there is no wrong or right answer and you have to build/brew on what ever system that you decide is best for you! I have brewed on both and each has their own advantages and disadvantages as the others have said above, however, both can and will make good if not great beer so it boils down to a personal choice! Good luck and cheers!!!
 
WAORGANY said:
BLUF is it comes down to a personal preference and what you want in your system..each to his/her own...there is no wrong or right answer and you have to build/brew on what ever system that you decide is best for you! I have brewed on both and each has their own advantages and disadvantages as the others have said above, however, both can and will make good if not great beer so it boils down to a personal choice! Good luck and cheers!!!
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I agree but certain types of equipment have actually performance advantages over other like for example for step mashing rims is far superior than most herms setup..and herms is more foolproof (safer) as far as setup and implementation. Both those factors may be a total non issue for one person vs another but just pointing out that its not as much of a trival preference as say whether to go with a bayou kettle vs a spike kettle..
 
I notice a lot of talk about Herms and Rims. How about Recirculating Direct Heat? (I.E. BIAB electric element and pump constantly recirculating from bottom to top of mash tun).
 
I like that sports car/bus analogy for RIMS/HERMS and I'd put the direct heat option in the bus category too since you can easily overheat your wort at points in your mashing process and you can't shut off that heat source. With a RIMS, the heat source disappears instantly.

The argument of scorching with RIMS is incredibly weak at best...as long as your RIMS is controlled with a proper PID with its temperature sensor immediately downstream of the heat source and there is sufficient flow across the element. Effectively controlling the heating element does avoid and prevent wort scorching.

Given the technology that we now have at our disposal, there is little question that RIMS is a better option.
 
RobbieOByrne said:
I notice a lot of talk about Herms and Rims. How about Recirculating Direct Heat? (I.E. BIAB electric element and pump constantly recirculating from bottom to top of mash tun).
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Recirculating e-BIAB is functionally the same as a RIMS, but the heating element is in the kettle, rather than in a tube that is part of the recirculation loop. As with RIMS, scorching, or overheating wort locally, is a possibility unless the controlling temp probe is located properly. Just like a RIMS, you want the temp probe located at the point where wort can be the hottest, and in an area of high wort flow. Thus you want the probe located about 1/8" - 1/4" away from the element, and between the element and the kettle outlet to the recirc loop.

Brew on :mug:
 
RobbieOByrne said:
I notice a lot of talk about Herms and Rims. How about Recirculating Direct Heat? (I.E. BIAB electric element and pump constantly recirculating from bottom to top of mash tun).
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Well the title of the thread Is Herm vs Rims... :) and you did ask the question?
Recirculating biab with the element under the bag and fb does work when implemented correctly but scorching is even more likely possible than many rims setups if the flow is not adequate around the element.
 
I'm on the verge of completely re-doing my system and have been debating this topic for quite some time, I'm just about sold on the RIMS. Although the term scorching keeps coming up, I'm not as concerned about that as it's possible and will be quite noticeable. What hasn't been brought up yet is heat stress or TBI. This is one of my only concerns about RIMS vs HERMS. Now, with the updated user controls, proportional SSR's, and ULWD I'm leaning more to the RIMS especially since I really want a smaller footprint.
 
Paulaner said:
What hasn't been brought up yet is heat stress or TBI.
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If the control circuit for the heater is properly installed and set up, there is no additional worry of increasing your wort's thiobarbituric acid content over what it would incur in a regular mash. TBA does generally take a long period of heating at boiling or higher temperatures. Typical mashing practice does not fit that condition.
 
mabrungard said:
If the control circuit for the heater is properly installed and set up, there is no additional worry of increasing your wort's thiobarbituric acid content over what it would incur in a regular mash. TBA does generally take a long period of heating at boiling or higher temperatures. Typical mashing practice does not fit that condition.
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We both agree on the proper installation reducing this. Any time direct heat is applied to your wort TBA will be produced, the question is at what level can it be tasted in the beer? This will be different for each person and you will also need to know what flavors you're looking for, or it could be there and you wouldn't even know that you're tasting this minor flaw. With most brewing systems you'll taste other flaws long before this. I'm striving for perfection in my beer and not cutting any corners which is why I'm finally purchasing the Stout Low O2 system and won't have to mess around with work arounds to brewing proper German beer. Again, I agree with you on setting the system up properly and that's why I've finally decided to go with RIMS. Now what would be interesting is do a side by side with exact systems other than the herms vs rims to find the nuanced differences.
 
At what temp are the enzymes harmed when the mash liquid is heated outside the mash itself ?
 
Enzymes are harmed at mash temps, but the rate of harm (denaturing) increases rapidly as temperature increases. For many organic chemistry reactions, the reaction rate doubles for each 10˚C (18˚F). I'm not sure if enzymes are more sensitive to temp increase than this. But in any case, there is no one temp at which denaturing starts. Because the rate of denaturing increases rapidly for relatively small temp changes, you don't want the temp around the heating element to be much hotter than the target mash temp, maybe about 5˚F max temp delta. Different systems may tolerate higher or lower deltas, depending on how long conversion takes in the system (mostly a function of crush size.)

Brew on :mug:
 
It's not the enzymes that you're worried about with TBA, this is a two-fold statement. Yes, during the mash the enzymes are what you're worried about, but TBA which is measured by the TBI or Thiobarbituric Acid Index, is typically something that happens during the boil (on the professional scale) now on our scale since we're heating the mash directly this becomes a problem on our scale. Here's a short process of what happens, maillard products and streaker aldehydes are formed, tannins oxidized and thus the thermal exposure of the wort is further increased and the wort becomes darker. The TBI of the wort prior to boil should be around 20-22. This all effects the flavor and life of our beer before it oxidizes, and not the wet cardboard oxidize but the sweet muddy malt flavor that oxidized beer has. Again, as I previously stated this can be a minor flaw or not even noticeable, but something to be aware of.
 
RobbieOByrne said:
Can you explain denaturing?
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Enzymes are complex proteins that are folded into specific shapes during their formation process. It's the particular shape of an enzyme that lets it catalyze a specific reaction. With the amylase enzymes, the reactions catalyzed are the hydrolysis of chemical bonds holding together chains of glucose molecules (starches, and polysaccharides.) When a bond is hydrolyzed, the chain is broken into two pieces, and the results can be either fermentable sugars, or longer glucose chains (aka polysaccharides.) It is these reactions that turn starch into fermentable sugar during the mash. At high enough temperatures, the shape of the enzyme gets distorted (some of the folding gets undone) and the enzyme can no longer catalyze the reaction that it used to (can't do its job anymore), in which case the enzyme has been denatured. Once denatured, enzymes cannot be repaired to make them functional again.

Brew on :mug:
 
So here is the thing... let's say our mash is at 140F and we want a mash temp of 150F. Let's say we are recirculating through the bed at a set flow of say, 1 GPM. The higher we heat the mash liquid (via HERMS, RIMS or kettle bottom) the faster the mash heats up.

If we return the mash liquid at 150F, it will take forever to heat the mash up. If we return the mash liquid at 160F, it heats up faster. 170F, 180F, 190F and 200F. It just gets faster.

So what is the highest practical mash liquid return temp that doesn't harm the mash ?
 
Last edited:
brewman ! said:
So here is the thing... let's say our mash is at 140F and we want a mash temp of 150F. Let's say we are recirculating through the bed at a set flow of say, 1 GPM. The higher we heat the mash liquid (via HERMS, RIMS or kettle bottom) the faster the mash heats up.

If we return the mash liquid at 150F, it will take forever to heat the mash up. If we return the mash liquid at 160F, it heats up faster. 170F, 180F, 190F and 200F. It just gets faster.

So what is the practical mash liquid return temp that doesn't harm the mash ?
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While I don't have a answer to the question your asking specifically I'll just point out with a 50ft Herms coil and a flow rate of appx 2.5 gpm (I haven't measured it in a few years) it only takes appx 5 mins to raise the mash temp of a typical 18g batch 10deg f. I think if you return at a higher temp than your mash target you're gonna get inconsistent temps. Cheers
 
Blazinlow86 said:
While I don't have a answer to the question your asking specifically I'll just point out with a 50ft Herms coil and a flow rate of appx 2.5 gpm (I haven't measured it in a few years) it only takes appx 5 mins to raise the mash temp of a typical 18g batch 10deg f. I think if you return at a higher temp than your mash target you're gonna get inconsistent temps. Cheers
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So this with the water in the HLT set to the desired mash temp ?
 

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