RIMS/HERMS: how do you choose?

[Brewskii]

the components seem really similar and I understand how they work... What makes a person choose one over the other?

or I suppose a better question is; is there a good resource for both sides of the coin?

 

[Malric]

I'm in the planning phase and chose Herms. I figured that a stuck mash was inevitable which means that you're likely to burn an element. I wasn't willing to take that chance.

 

[OneHoppyGuy]

Use a fluid sensor and you won't burn out your element. With a good false bottom you shouldn't experience a stuck mash.
As for resources, this site has lots of information, just start digging.
TheElectricBrewery.com has a good example of a HERMS. BrewersEquipment.com and StoutTanks.com both sell excellent RIMS tubes.

 

[aquenne]

Im also using my herms coil as a dual use wort chiller as well. i just pump wort thru the coil while the hlt contains ice water

 

[flananuts]

I chose herms for a similar reason where my chillzilla operates as the heat exchanger for mash and for cooling plus it limits any caramlization to just the boil. Dogfish head built their business off a rims rig and he has some good information about some if the rims tube cleaning challenges.

 

[itsme6582]

I'm working on a herms setup right now. I figured I already have a nice heat exchanger to chill so why not use it to heat as well. That pretty much made my decision for me. It'll be similar to that Chillzilla setup mentioned above. The obstacle for me to overcome is running a heating element with 2 pumps on one circuit.

BobbyM just started selling rims tubes on his site for only 75 bucks. It's just the tube but I couldn't beat 75 bucks without slowly acquiring parts from work.
Brewhardware.com

 

[jpalarchio]

...I couldn't beat 75 bucks without slowly acquiring parts from work.

OT but this instantly reminded me of Johnny Cash's "One Piece at a Time"... Classic.

 

[itsme6582]

OT but this instantly reminded me of Johnny Cash's "One Piece at a Time"... Classic.

Nice

 

[microbusbrewery]

They're pretty much the same except for the way you apply heat to raise/maintain temps. With RIMS the heating element is in direct contact with the recirculating mash and with HERMS a heat exchanger immersed in hot water handles the heat transfer (kind of like using a double-boiler). I prefer HERMS because there's no chance of scorching the mash. I'm not saying a RIMS will scorch the mash, but it's possible. Also with a RIMS you can experience caramelization and/or darkening from being in direct contact with the element; that may not be a bad thing depending on the style you're brewing. Both tend to not work as well with step mashes because they tend to respond a little slower than direct fire.

 

[flananuts]

I would recommend running a 240v and 110v circuit to your controls. I did mine on one circuit but the changes in draw when I turned on my pumps would trip my gfci beaker in the panel. Plus when I run sanitizer or cleaning I can do it with my 240v disconnected.

 

[Cpt_Kirks]

I'm in the planning phase and chose Herms. I figured that a stuck mash was inevitable which means that you're likely to burn an element. I wasn't willing to take that chance.

This.

Seems to me there is simply less to go wrong with a HERMS. The hot water acts as a buffer.

With an element...you have very little margin for error.

I don't need stressful brew days. I brew to relieve stress.

 

[dfess1]

I have a direct fired RIMS system. I also don't have any automation in any of mine. I like the fact that I have to "touch" my system while brewing, that it isn't completely hands off. I also like the fact that I can make a small beer from a large grain bill, and have that small beer boiling while I have my initial beer brewing in the BK (use my HLT as a second BK). I use a PC for cooling though, so I don't have to worry about having my HLT free to put in ice water.

 

[Homercidal]

I'm in the same boat and I think I'm going HERMS for a few reasons:

1) I'm already heating sparge water, so why not use that hot water to maintain temp in my MLT?

2) Less parts. I already have a HLT, so all I need is a copper or stainless coil. With RIMS, you have to have another element, and either swap controller with the BK, or wire another controller in. Plus another element.

3) Cleaning. I've heard there are difficulties in cleaning a RIMS tube unless you have one with tri-clover clamps and take it all apart each time to clean it. With HERMS I believe it could be convenient to pump the sparge water through the HERMS coil to clean it during the the sparge.

4) Risk of overheating/scorching. With HERMS there is practically ZERO chance of scorching or even overheating unless you do something stupid.

I really thought I wanted a RIMS system when I first started thinking about upgrading. I was used to the system since we use a similar method to heat molds at our shop. But, even though the heating system is the same, the application is very different.

A RIMS tube is compact, but since I already need a HLT, it's still an *extra* piece of equipment when it's all said and done.

I won't be using my HERMS coil for chilling though. I already have a CFC and will likely upgrade to a decent plate chiller once my rig it up and running and I run out of other things to buy and my pre-chill filter method is proven over a few batches. Otherwise, it's another possible benefit to using HERMS.

 

[Brewskii]

I just found this ...
http://www.winning-homebrew.com/RIMS-HERMS.html

It seems fairly comprehensive.

 

[Brewskii]

QUESTION: PID in HERMS set- up is controlling the mash temp via the temperature of the HLT. So the feed back for the PID is the mash temp, correct?

 

[audger]

I figured I already have a nice heat exchanger to chill so why not use it to heat as well.

because of properties that no one usually thinks about...

what makes a good herms coil doesnt make a good chiller, and vice versa. the operational requirements for each are much different. for the chiller, you want maximum possible surface area of the heat exchanger to make more efficient use of each gallon of chilled water. the ability to quickly cool the wort is only secondary to that because it can be made up for by simply wasting lots of water.

for a HERMS coil, the goal is mainly to keep a very tight temperature tollerance, and also it needs enough flow as to not bog down the pump and so that the temperature change is reflected quickly in the mash itself. low flow can be made up for by increasing the legnth of the coil ind increasing the HERMS exit temperature, but at the expense of not being able to drive the heater as hard, or at the risk of overshooting your temperature in the mash itself. the longer the wort sits inside the coil, the more it will heat. if its spending a long time in the coil, the temperature difference between the wort and water bath cant be as large (and thus, heat flux will be lower, and wort heating will be less efficient). also- the more poorly your HERMS is designed, the more you will need to rely on good PID settings to make up for it.

so for a chiller; the ideal design would be one, or several parrallel, long thinner legnths of coiled copper tube. a HERMS coil would idealy be a short, thicker-ID coil. any dual-use designs would only be a compromise between the two optimal designs of each use. there are also many... "non-ideal" lets call em, designs floating around the internet. people stick 100 feet of 3/8" copper in a 15gallon HLT and call it a HERMS. do these designs work? sure... it seems to make beer... so no one gives it any more thought.

you can use one for the other, the same way you can use a torx bit to drive an allen-keyed screw.

QUESTION: PID in HERMS set- up is controlling the mash temp via the temperature of the HLT. So the feed back for the PID is the mash temp, correct?

more accurately it should be the HERMS output temperature. if you are measuring only the mash temperature, and it takes 5-10 minutes for a temp change to be registered by that temperature probe, you could be denaturing all the enzymes that flow thru the HERMS coil for those 5-10 minutes. if your flow rate is .5gpm, and your total mash has 10 gallons in it, 30-50% of your enzymes could be denatured before the controller turns off the heat. also the "farther away" your probe is from the controlling heat source, the greater the error you will have.

 

[LandoLincoln]

I just found this ...
http://www.winning-homebrew.com/RIMS-HERMS.html

It seems fairly comprehensive.

It states that HERMS or RIMS is good for step mashing, but I've read that those systems aren't very good for step mashing.

Maybe a direct-fired MLT with a recirculating pump is good for step mashing, but a HERMS setup or a RIMS tube setup isn't good for step mashing? Anyone want to back that up?

I'm also concerned about using my pump for recirculating a mash with a non-priming beer pump. How do you get a sufficient amount of wort flowing through the pump so as not to cause air cavitation, yet not cause grain bed compaction because your flow rate is too high? I know people do it, I just don't understand how.

 

[Brewskii]

It states that HERMS or RIMS is good for step mashing, but I've read that those systems aren't very good for step mashing.

Maybe a direct-fired MLT with a recirculating pump is good for step mashing, but a HERMS setup or a RIMS tube setup isn't good for step mashing? Anyone want to back that up?

I'm also concerned about using my pump for recirculating a mash with a non-priming beer pump. How do you get a sufficient amount of wort flowing through the pump so as not to cause air cavitation, yet not cause grain bed compaction because your flow rate is too high? I know people do it, I just don't understand how.

Sounds to me like your restricting flow on the suction side of the pump. You should start and stop pumps while supplied and filled with liquid and with no flow. So you would open the valve path to flood the pump, close the discharge of the pump, turn it on and then control flow with the discharge valve.
You don't want to "string" wort into the pump... Bad things will happen.

 

[LandoLincoln]

Sounds to me like your restricting flow on the suction side of the pump. You should start and stop pumps while supplied and filled with liquid and with no flow. So you would open the valve path to flood the pump, close the discharge of the pump, turn it on and then control flow with the discharge valve.
You don't want to "string" wort into the pump... Bad things will happen.

I don't have a valve on the in-flow side of the pump. Well...I do have a valve on my vessels, but when I do use the pump the vessel valves are always on full open.

Yeah, I guess that makes sense to have the outflow valve control the flow of the wort to recirculate back into the mash. There really is no other way when using a non-priming pump. So I guess I just have to stop fretting over it and just give it a try on my next brew day.

 

[flananuts]

I've step mashed a number of wheat beers without any challenges. It all depends on your setup and how quickly you can ramp temps.

 

[itsme6582]

because of properties that no one usually thinks about...

what makes a good herms coil doesnt make a good chiller...

That was just too long for me to get through. Heat doesn't care which way it flows. Think outside the box.