Question about HERMS

[Cheesefood]

So if this is a typical HERMS setup, then I have a question. Why haven't I seen any setups where 158' water is pumped from a direct-fired HLT into an immersion chiller which is placed in an MLT and routed back to the HLT? Wouldn't this allow for steady temperature holding without increasing the amount of mash water? It could also make for an easy mash-out. And just as easily as it heats an MLT, it could cool as well. Additionally, you'd never risk scorching the wort with direct heating elements.

Thoughts?

 

[Bellybuster]

the mash would continually need to be strirred. Heat the wort not the mash, requires less energy and fuss.
my system is very similar to the one in the link, I use a seperate heat exchanger instead of running the coil thru the HLT


this was a personal opinion...not to be construed as policy

 

[Cheesefood]

I don't see why constant stirring would be necessary. I think that if properly constructed, this could provide a very easy way to control temps. Does it really matter whether you're heating the grains or the wort? Seems like heat is heat.

Likewise, (and try to be civil here) what about attaching a vibrator motor to the coils to stimulate movement? (Wait at least 3 honest replies before making gay jokes).

 

[JeepGuy]

Stirring would be necessary to prevent hotspots near the heat exchanger. Even the herms system you linked to has a pump to move water around in the heat exchanger to prevent hot spots in it. It seems to me like it would be harder to prevent hot spots in the mash than it would in a heat exchange like in the link. I don't know if a vibrator will stimulate a mash enough to prevent this. I like where you're going with this and am going to do some more thinking on it. Maybe there's a better way to stimulate that mash to get it hot all over, not just in spots.

 

[Bobby_M]

Frankly, I wouldn't care about hotspots in the HLT or dedicated heat exchanger because you're only concern is the output temp of the wort returning back to the mash.

If you used a coil in the MLT as the heating element, you'd certainly have hot zones near the coil unless you also recirculated the mash back onto itself.

The major advantage to doing a recirculating mash, whether through HERMS or not, is that you're equalizing the temps throughout the whole mash and doing a really long vorlauf for clarity. Stirring the mash with the coil in place would be a pain and so would cleaning it later. A coil in the HLT never has to be cleaned. In fact, if you keep your HLT covered at all times, you don't even need to touch it for years.

 

[jbreiding]

waiting for one more reply.

i think the placement of the thermometer is not the best. i would think you would want it near the drain in the MLT to make sure the entire vessel of water has reached that temp, not just what is coming out of the coil.

 

[HenryHill]

I've been biting my tongue/restraining my typing digits on this one....I don't know the best answer to much, if anything, in the world, so's I asks fellers who may...

When I asked the local gurus about direct firing and recirc-ing with in the MLT, or using the HLT as the heat source and recirc-ing the wort thru it, I was told that, yeah, they work, but if you just recirc the proper temp water to a heat exchanging coil in the MLT, you will achieve a decent even temp, wont have to stir, and won't have to risk direct heating the wort or pump grain.

You're done with the recirc coil after mashing, since the sparge water is there only long enough to be distributed thru the mash and drained. You pull the coil after the mash has had it's 60 mins or whatever you do, and the sparge water goes in, ya stirs, and out it comes...maybe twice, maybe thrice if you are want every possible % of effic.-personal choice there...

Big brewhouse systems gravity flow the wort out of the lauter tun and then pump it from a very small holding tank UP to the boil kettle. The reason is that pumping disturbs the grain bed and gravity lautering draining is superior for grain contact with water.

http://s239.photobucket.com/albums/ff82/MaynardHill/Brewing/?action=view&current=IMG_4003a.jpg

 

[Bellybuster]

the thermal mass of an entire tun of grain and wort is huge. It would take much more energy trying to maintain temps by circing hot water thru a coil in the mash than circing wort thru a coil in a heat exchanger or HLT.
The premise behind having your temp read at the exchange out put is simple...continue dumping 152 deg wort into your mash tun and the entire tun and contents will be 152 degrees, especially if your stirke water addition was bang on for 152.
As far as having the coil in the mash tun...take a temp reading right next to the coil and another 2 inches from the coil, they're gonna be different. The heat required to maintain temp right next to the coil is small but the heat required to maintain the mash temp further away from the coil will be much greater requiring higher heat in the coil. The idea is good but to have even temp either the coil needs to move thru the mash or the mash needs to move around the coil giving even contact.
I have no idea whether any of that makes sense but it does to me. Feel free to completely disregard.
as far as pumping disturbing the grain bed??? Doubtful unless you're creating suction on the output. Very little suction created by a mag drive pump, that's why they are not self priming

 

[Bellybuster]

here's a great link that explains one guy's theory on HERMS, relevent to this conversation??? who knows, but a good read

http://sdcollins.home.mindspring.com/HERMS.html

 

[HenryHill]

I'm setting up for this, and here's why I'm heading in this direction...

If you are even close to hitting the strike temp to get your desired mash temp, and then use the heating coil in the mash to maintain that temp, there should be little to no heat stratification due to adding heat externally at the bottom, as with direct fire. There should be little need to stir the mash, as that really is just to keep the mash at the same temp due to cooling effects over the course of the 60 minute mash. The strike water does the primary heat input, and using a keggle as a MLT, heating the mash by recirc-ing fro the HLT water is really adding only a subtle amount of additional heat. My plan is to use PID's in each keggle, where the MLT PID controls the pump, and the HLT controls the Asco valve /burner for the HLT. Strike is heated in the BK, using PID hooked to burner/Asco valve...while mashing heat control is heated in MLT....

Stirring in a cooler during the mash isn't needed unless you are trying to get rid of too much heat....

Once the mash has gone 60 minutes, I see yanking the coil, and vorlauf and runoff, and double sparging with stirring, as usual.

Temp/weather conditions will make this a variable as to how much additional heat is needed, as seasonal changes will make garage temps different season to season...

If I can find someone that has tried it and/or someone that has failed at this, I may turn back; but I haven't found this has been done-and can't understand why not.

 

[Bellybuster]

I think it's really cool when folks try new and different things..too many of us get stuck in "that's just the way it is". Experimenting is the real escence of home brewing.
Keep us posted on how you make out, I can't say I've ever seen a coil immersed in the mash, I'm interested

 

[Bobby_M]

Maybe I'll go at it from the other side. What do you think the advantage would be in putting the coil in the grain instead of the HLT. I like the idea of being able to somewhat permanently installing the coil into the HLT and never having to clean it. I think that's a huge advantage.

 

[the_bird]

I've been confused by the whole HERMS/RIMS thing, and have had the same thought as Cheese regarding a setup that would run hot water through a coil in the mash. My thought was that it would be easier to keep the exterior of a copper coil clean than to clean out the inside, but I guess it's just a matter of running some cleaner through the coil.

 

[Marinebrew]

Not sure it will work, but I too think it is cool when folks try something new. It would be neat to use a counterflow chiller to reheat the mash by circulating 158 degree water around the wort, but I can't think of a way to do it without two pumps, and I'm way too cheap for that.
I am presently using an immersion coil in my HLT, and I am using a small motor with a propeller to stir the water for better heat exchange in the HLT, but I am considering using my pump to recirculate the HLT water and create a whirlpool for better heat exchange. Any thoughts?

Dylan

http://www.mcgeheefamily.com/documents/Brew Frame.htm

 

[billtzk]

There sure are a lot of different ways to go about this. Since I'm building a Brutus Ten, I plan to direct fire the mash and constantly recirculate it to itself. I think that is going to work fine for me, but if it turns out that I'm not satisfied with that approach, I'll go the HERMS route.

If I end up going HERMS, then I might try the plate heat exchange approach since I'll have two pumps anyway. I've never much liked the idea of the having a copper coil permanently installed in my HLT.