RIMS and HERMS

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batfishdog37

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Ok, I cannot find a specific thread right now about either( I'll confess, i didn't look too hard). I understand that RIMS means Recirculating Infusion Mash, but what I am not entirely sure about is why. From what I gather the water is recirculated through a heater of sorts and then back through the mash, correct? Is this advantageous in some way over simply mashing in an MLT cooler? Also I don't quite understand what HERMS does. Thanks:)
 

Lil' Sparky

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They both do essentially the same thing, and the benefit is to maintain your mash temps exactly throughout the entire mash. They can also be used to step up the mash temps without adding additional water infusions. HERMS systems typically use a coil in the HLT (or separate vessel) as the heat exchanger. RIMS systems typically run the wort through a tube with an electric heating element. Since they're typically controlled electronically, it's more of a hands-off, set it and forget it system as far as the mash is concerned.
 

The Pol

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All good info, but I have yet to see a RIMS or HERMS that can efficiently and quickly step up temps.

In fact, if you do some research on HERMS, it is not at all recommended for mash steps. You can mash out with it, but that will still take you 20 minutes to get from 155 to 168 in a cooler MLT generally.

If you build one of these, do it to maintain temps, do not build it to step mash, you will be disappointed.
 

Laughing_Gnome_Invisible

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I agree about the slow steps. I think a HERMS would be too slow for that. The reasons i set up my ghetto HERMS was to take my own ineptitude out of the mashing process. I don't think i was performing well with my mashing and batch sparging. I have only done two batches with the HERMS, but thus far they have been much more consistent with a higher efficiency. IMO, one of the major benifits for me might be that I am getting a LOT less grain particles in the boil kettle.

edit. When I say a lot less grain particles, I mean zero grain particles. :)
 

Lil' Sparky

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Pol/Gnome - is this because the heating element in the HLT can't raise the temps fast enough? Would it be able to if you had more heating power?
 

Lil' Sparky

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Direct-fire + recirculation does a great job raising temps, but the down side is that it's tough to accurately maintain temps unless you go the BRUTUS route w/ electronically controlled gas valves. That's a lot of $$ and extra fabrication, though.
 

beerthirty

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I use a direct fire recirculating mash. No scorching and can go from 146* to 172* in about 10 min(of course the ambient temp of 100*+ might have something to do with this) ;). The wort that flows to the BK is clear as finished filtered beer.
Sparky is right I do have to watch the thermometer very closely.
 

Laughing_Gnome_Invisible

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Sparky, my set up is very limited, Pol is the brewing sculpture techno guy, I defer all the technical info to him. :) ......*Bails out sheepishly*
 

The Pol

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Pol/Gnome - is this because the heating element in the HLT can't raise the temps fast enough? Would it be able to if you had more heating power?
Has little to do with the size of the element. I can have a 1500W element or a 4500W element in the HLT... the problem comes that you are trying to change a HUGE thermal mass (GRAIN + water) in the MLT) You are recirculating through a 1/2" ID coil and hose at about 1.5gal/min.

It takes me 5 minutes to get my HLT from 155 to 165... but it takes my MLT 20 minutes to get there. Once the HLT is up to temp, the hard part is passively heating the MLT. The HLT remains at the set temp, but the recirc, though fast, is a trickle compared to the ammount of thermal mass in the MLT.
 

The Pol

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I use a direct fire recirculating mash. No scorching and can go from 146* to 172* in about 10 min(of course the ambient temp of 100*+ might have something to do with this) ;). The wort that flows to the BK is clear as finished filtered beer.
Sparky is right I do have to watch the thermometer very closely.
If you direct fire, that is A LOT different. Look at the BTUs...

I mean, my 5500W element in my BK doesnt come close to 10% the BTU of a typical LP burner.

If you are direct firing you arent heating the liquid only as you are in the HERMS or RIMS. You are heating the ambient air, the kettle, the mash and the mash water. It is DIRECT, not PASSIVE as in a RIMS or HERMS. Couple that with the fact that you have 10x the BTUs available and this is why direct fire is a different beast altogether.
 

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But you said it wasn't about the size of the element. I think the difference is w/ direct fire, the wort exiting the bottom of the kettle is far above your target temp, whereas the wort exiting your HERMS coil is at the target temp, so it takes forever for the entire mash to reach the target. If you overshot the temp in the HLT (at least for most of the step) the ramp up would be much faster. Ensuring you don't overshoot your target will become more difficult - just like w/ direct fire.

I may disagree at least a little about the direct-fire method directly raising the temp of the grain bed. Maybe a little right where it contacts the edge of the MLT, but I've got a full FB in my keg that holds at least 1 gal of wort that sits between the keg bottom and the grain. Since I recirculate very fast, I think the wort is absorbing the majority of the heat, and the temp of the grain bed is raised by the hotter wort being dumped back on top of the mash and then circulating through. There is quite a bit of stratification in the temperature of the mash, but at that point we're not trying to maintain temps, we're trying to raise them, so I don't know that it's really an issue.

Really the best of both worlds is an electronically controlled direct-fired system like BRUTUS. It can maintain temps and raise temps equally effective. It's just the extra cost and construction that's the problem for me.
 

caskconditioned

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Has little to do with the size of the element. I can have a 1500W element or a 4500W element in the HLT... the problem comes that you are trying to change a HUGE thermal mass (GRAIN + water) in the MLT) You are recirculating through a 1/2" ID coil and hose at about 1.5gal/min.

It takes me 5 minutes to get my HLT from 155 to 165... but it takes my MLT 20 minutes to get there. Once the HLT is up to temp, the hard part is passively heating the MLT. The HLT remains at the set temp, but the recirc, though fast, is a trickle compared to the ammount of thermal mass in the MLT.
I'm really glad I read this post. I use an external HERMS chamber instead of my HLT. It holds about 1.5 gallons of water and has a 1500w element (or maybe it's a 1000w element). Anyways, I can only maintain temps and or do small adjustments as Pol pointed out (10 gal batches). I'm going all electric one day and was thinking of just adding a bigger element (4500w/240v) to the HERMS to try to accomplish step mashes. But I never really thought about the thermal mass etc. of the MT. Plus with the increase size of the batch, I have a lot more water/grain to heat up. Makes sense and I think I will just not use my HERMS for step mashes and go via the infusion method.
 

Lil' Sparky

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Maybe the cheap solution for me would be to add a HERMS coil and a heating element to my HLT (or maybe some other vessel) to maintain temps, and still use the burner to raise the temps when I need to...
 

Boerderij_Kabouter

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I am going to be using a direct heated MLT with a herms in my direct heated HLT. The burners will be used for steps and the herms will only maintain the temps between steps. I think if you are a brewer who often uses steps, this is a good way to go.
 

beerthirty

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Maybe the cheap solution for me would be to add a HERMS coil and a heating element to my HLT (or maybe some other vessel) to maintain temps, and still use the burner to raise the temps when I need to...
I like that idea of adding a HEX to the HLT. When maintaining the temp with direct fire the flame needs to be very low or the temp will overshoot killing off all those beautiful little enzymes I'm trying to foster. Damn you Sparky, now I have another project on the plate.:D
 

The Pol

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HERMS and RIMS are limited because the general RULE is NOT to heat your wort in excess of your desired target temp. This limits you, because you are not getting full use of the WATTS or BTUs available, because you are throttling it back to say 155F instead of 180F when you are trying to step up to 155F in the MLT. Doesnt matter if you have 5500W or 1500W... the HEX is only 155F or 170F.

If you are just going to overshoot the wort return temp, then yes, a larger element will help, but that is generally NOT how a RIMS or HERMS is run. There are reasons for this, but we dont have to get into that now.
 

Boerderij_Kabouter

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Sparky beat me to the punch.

What Pol lays out above is the reason for the difficulty of herms to do quick steps. Good explanation, have you talked about a herms before??? :D

I use a recirculating direct-fired MLT now for my steps. I do not yet have my herms installed. I can tell you that if you are recirculating during direct-fired steps, it is easy to control overshoot. It was a challenge before I had the pump though. That was a touchy process. With the pump, it is very easy.
 

Lil' Sparky

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HERMS and RIMS are limited because the general RULE is NOT to heat your wort in excess of your desired target temp.
OK. So for maintaining temps, I get the not overshooting thing, but why not for raising temps, at least until you get close to your target? That's basically why direct-fire is able to accomplish the step so much quicker. Once you start getting close to the target, you can set the HERMS temp to your target, the heating element will no longer come on, and the heat exchanger will draw the extra heat out of the HLT as the mash is heated the last few (several?) degrees. Seems like it would work OK to me...
 

pompeiisneaks

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I'm using electric HERMS, and I've not yet done any stepping, but I understand the problem w/ the slowness, but realize that this time doesn't hurt anything w/ respect to the mash, just makes it take longer... and since my system is automated, I can leave it to do its magic and come back later... so an extra 20-30 mins per step is a tad annoying but worry free...
 

Lil' Sparky

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I can tell you that if you are recirculating during direct-fired steps, it is easy to control overshoot. It was a challenge before I had the pump though. That was a touchy process. With the pump, it is very easy.
I agree, with a pump recirculating WFO and a burner on low, you can keep from overshooting your target.

I recently added a digital thermo fitting to my pump (need to take some pics of this) so I'll be able to monitor the temp of the wort exiting the MLT, not just in the mash, which is hotter on the top than the bottom. I hope this will help me monitor things.
 

The Pol

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I may disagree with the time not being an issue in the mash.

If you start at 125F for a protien rest and it takes 30 minutes to step to 155F... you are going to have a much more fermentable wort than you would if you stepped right up to 156F. Why? Because you are converting sugars during the ramp up through 140, 145, 148...etc.

I personally think that a slow step (ramp up) will give you a different profile than stepping directly to your desired temp.

I have actually seen some BIG Belgian ales require a slow "ramp" mash for this very reason, it produces a VERY fermentable wort.
 

Boerderij_Kabouter

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OK. So for maintaining temps, I get the not overshooting thing, but why not for raising temps, at least until you get close to your target? That's basically why direct-fire is able to accomplish the step so much quicker. Once you start getting close to the target, you can set the HERMS temp to your target, the heating element will no longer come on, and the heat exchanger will draw the extra heat out of the HLT as the mash is heated the last few (several?) degrees. Seems like it would work OK to me...
The problem here is that you are creating a very complex heat transfer situation. In order to do this in any sort of repeatable way, or to hit intended temps, you would need to do some rather intense math or modeling. Every mash would be different because of volumes, grain bills, etc. IMO this is just not workable. Unless you only used the herms for steps and not maintaining temps. Then you could have your HEX in boiling water and ramp much more quickly.

I'm using electric HERMS, and I've not yet done any stepping, but I understand the problem w/ the slowness, but realize that this time doesn't hurt anything w/ respect to the mash, just makes it take longer... and since my system is automated, I can leave it to do its magic and come back later... so an extra 20-30 mins per step is a tad annoying but worry free...
The downside here is that you will always have super attenuated wort and be left with dry beers. Maybe not, but that doesn't sound optimal to me. I would do steps with boiling water infusions if I were you. You could do some reading on German brewing techniques for more info on that.
 

pompeiisneaks

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If I want not super attenuated wort, I just do single mash no mashout... not that hard... if I want the big belgians I can do the step proces... it allows flexibility. I'm glad you all explained that, though. I wasn't aware that slower ramp up gives you the dryer beer. Interesting. I can't think I'd be doing a lot of step mashes, but now I want to try it on my next beer, its a belgian dubbel... what cases would I want to do the faster step? I would bet, though that w/ my system, I could do decoction pretty easily, i.e. I pull off a gallon and boil it up and readd... that would solve the slow problems pretty quickly. I think thats what you mean by the german methods or at least one of them right?
 

Boerderij_Kabouter

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You are correct. The slow ramp, as Pol said, just brings you very slowly through the sacc rest range. Which means you will be converting your wort at for the entire step plus whatever your rest time is. Also, at lower temps, the enzymes more completely convert your wort and yield a more fermentable beer (i.e. drier). This may or may not be desirable, it is just something to keep in mind.
 

jkarp

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Hopefully kaiser will chime in to confirm, but I think modern malts convert so darn fast, unless your step mash temp increases are damn-near instantaneous, they're pretty much a waste of time. I've seen negative iodine tests in as little as 20 minutes before. That means there's likely nothing left for the alpha-amylase to chew on if it takes you 30 to get there.
 

The Pol

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Step mashing is only used in my house for protien rests... 125F then up to 154F or so with an instant infusion.

If you spend much time at all in the alpha-beta range, it is done.
 

Lil' Sparky

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The problem here is that you are creating a very complex heat transfer situation. In order to do this in any sort of repeatable way, or to hit intended temps, you would need to do some rather intense math or modeling. Every mash would be different because of volumes, grain bills, etc. IMO this is just not workable. Unless you only used the herms for steps and not maintaining temps. Then you could have your HEX in boiling water and ramp much more quickly.
In principal, you are correct, there's a lot of math that goes into it. In practice, though, it may not be so hard. It would probably just take a little trial and error. I think in practice, setting the HLT at just a few degrees above your target (maybe 5-10º) could have a big impact on how long it takes. When you're a few degrees from your target, you set the HLT to the target temp, and excess heat in the HLT will be transferred to your mash, and the heating element wouldn't come on until the HLT falls below your target. I think it would be a valid experiment, anyway.
 

The Pol

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You guys keep talking... my rig has certain limitations, but I have them worked out. I will be brewing this coming weekend, cant wait!!!!

I get to try the new sight guages and silicone hose.
 

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I think the assumption that direct fire tuns are better for step mashing is erroneous. First, just because one CAN apply 100kBTU doesn't mean you should. At that capacity, you couldn't run the pump fast enough to keep the wort from getting way too hot. It's one thing if you're trying to mashout and knock out conversion, but running the entire wort through a zone of heat over 180F a couple times is a good way to completely denature everything. I think I run my burner at about 30kBTU when I'm heating and I run the pump on full speed.

It's the same reason why Pol says you shouldn't set your RIMS controller to overshoot your desired temp.

I've argued in some other thread that the only reason I'd recommend a higher wattage element in a RIMS HEX is if at your max pump speed, the wort output is LOWER than your controller's set temp. That is the one case where wattage is hurting your potential ramp time.

I think step mashing via decoction or direct infusion is very repeatable. I don't think it's impossible to duplicate the same effects via slower ramp timess, you just have to start them earlier. If the schedule is 114F for 15, 122 for 15, 146 for 20 and 158 for 30, you can do something like dough in to 114F and immediately set your controller to 122F. If it makes it to 122 in about 15 minutes, set the controller for the next step, etc.

Enzymes are not binary and activation/denaturing occurs on a curve. This technique can be repeatable on your own system but not necessarily an exact replacement for a known, rigid mash schedule.
 

Lil' Sparky

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Hey I just got new silicon hoses, too. I like them much better than the braided hoses I was using!!
 

Boerderij_Kabouter

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I think the assumption that direct fire tuns are better for step mashing is erroneous. First, just because one CAN apply 100kBTU doesn't mean you should. At that capacity, you couldn't run the pump fast enough to keep the wort from getting way too hot. It's one thing if you're trying to mashout and knock out conversion, but running the entire wort through a zone of heat over 180F a couple times is a good way to completely denature everything. I think I run my burner at about 30kBTU when I'm heating and I run the pump on full speed.
QFT- Don't run those huge burners directly on your mash!!! I use a superb burner set to its lowest setting with the flames barely going. That is all you need. My rest go very quickly and any more than the absolute minimum and the overshoot can be substantial. I learned that the hard way.
 

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The best way to change the temperature of something is to alter its mass and its heat content. Adding boiling water does both without the risk of overheating. Someone tell me why they are happier with a more expensive and complicated system. I have a well insulated container, a heat source, a very accurate thermometer and an ever boiling pot of water. If this fails me, or if I don't wish to change the mash volume, then I either warm a portion of the wort, or a portion of the grain (style dependent).
 

The Pol

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The best way to change the temperature of something is to alter its mass and its heat content. Adding boiling water does both without the risk of overheating. Someone tell me why they are happier with a more expensive and complicated system. I have a well insulated container, a heat source, a very accurate thermometer and an ever boiling pot of water. If this fails me, or if I don't wish to change the mash volume, then I either warm a portion of the wort, or a portion of the grain (style dependent).
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