HERMS

[Kbar]

Making the jump to HERMS from my RIMS system. Issues with scorched mashes and maintenance and a new "Stout Tanks" HERMS based HLT have pushed this move.

To all the HERMS users, need your feedback. I am going to run constant circulation on the wort and plan on running the HLT at some higher temperature than what the mash is. Could be 2F or more.

My question is, if anyone does run this style system, what do they do and what process do they find best works for them.

Thanks in advance!

[EL TIZZO]

I'm in the same boat. My herms system is 95% built and I would also really appreciate some feedback on what I can expect come brew day. some details about process would be very welcome. Mine will be manual at first with PID controllers on the way.

Thanks in advance and cheers

[BDawg]

My buddy had a HERMS (he still would but he won the Blichmann system at the NHC - lucky bastard)
The thing I noticed was that the temp differential was significant enough that sparging actually became an issue.
Here's why- in order to raise the mash up to mashout temps, you really needed the herms to be in water way up around 180 or so, otherwise the mash wouldn't get up there fast enough. At that point, the HLT water is too hot to be used for sparging. He had to play the game of cooling the sparge water down by adding cool water, etc. It was a pain in the ass.

This may be overkill, but if I was building my own HERMS system from scratch, I'd keep the HERMS recirc out of the HLT and instead build a separate HERMS vessel. It would use an electric heating element, with temp control, probably be made from a 10 gallon gott cooler. It would have a propeller to keep the hot water moving around within it (so that the HERMS coils can absorb more heat without the "thermal blanket" effect you see where you have to move your wort chiller around for it to be effective) It would sit on the side and only be used to control the mash temp.
The sparge water in the HLT would be heated and controlled separately.

[Ozwald]

My last system was an HLT-HERMS & it was fantastic. I had none of the issues that BD was describing. I'd still be using one, but I upgraded my MLT & BK to much, much larger vessels & the old HERMS coil wasn't large enough to handle over double the volume. I'm temporarily running a RIMS tube (which I hate), but only because I haven't upgraded the HLT yet. When I do, I'll be building another coil for it.

A separate vessel would definitely work, but it's usually just a matter of correctly manipulating your system. Mine was an all manual 2-tier. I didn't do a constant recirc with mine, only for ramping & holding the mash out at temp. 2F over is going to give you a real slow ramp. I'd suggest something like 8-12 over, depending on your system. The coil length/diameter, geometry & flow rate are all going to play a part. HERMS coils have a skin-effect, so that also has to be taken into account.

I would get my HLT up in the mid 170's, but killing the heat at the right time will drop that to 170 without a problem - remember a heat exchanger doesn't just work in one direction, you can use the mashout temp to drop the HLT temp.

Really HLT-HERMS brewing is mastering your flow-rate & timing. It can be pretty tricky to learn. The two pieces of advice to getting it down I can give: stay sober & take notes on temps/times/flow rates. Don't circ too fast to minimize skin effect & maximize transfer. It is possible to go too slow though.

[Kbar]

Good stuff Oz and Bdawg. I do have to 15 gallon HLT's now with the new Stout Tanks HLT-HERMS tank. I contemplated going the two vessel route with one being dedicated to Dough in and Sparge water and one to the HERMS system.

I currently use a pump to do the stirring in lieu of a stirrer. Works well, just another noisy pump running though. I use it intermittently vs. all the time on. Just to reduce the heat stratification.

Yes, going to be a learning curve. I did perform some step mashes with the RIMS system, but that was frustratingly slow. I have also read that too slow of a step mash can lead to issues such as loss of head retention.

The original plan was to run a 2F higher HLT HERMS setting than the desired mash temperature and run the mash pump constantly.

Will keep the recipe simple, single infusion, and take data. More to come. Thanks all.

[BDawg]

Good to plan on the temp drop, but it may be more than 2F. It will all depend on ambient temps, hose length, mash tun losses, etc, of your setup, which is unique to you.

Good Luck!

[Stinkfist]

Yeah I have not had those issues with my HERMS...Just make sure you are measuring the temperature of the water coming out of the HLT coil and make the distance as short as possible. I have noticed very small deltas between the mash temp and the HLT temp(though I do have a 50 foot coil in a 10 gallon cooler, with a stirrer) So when I set my temp it is within +\- 1 degree from the HLT temp. So I have no issues with the Mash out. Another reason I may not have this issue is I use coolers for both the mash tun and the HLT.

[Charlie]

...This may be overkill, but if I was building my own HERMS system from scratch, I'd keep the HERMS recirc out of the HLT and instead build a separate HERMS vessel. It would use an electric heating element, with temp control, .... It would have a propeller to keep the hot water moving around within it (so that the HERMS coils can absorb more heat without the "thermal blanket" effect you see where you have to move your wort chiller around for it to be effective) It would sit on the side and only be used to control the mash temp.

That's the arrangement I'm using. I re-purposed the mash tun from my old 5 gal system. This is it.



For a mash at 152 I run the HERMS at 156. Recirculation is under manual control with roughly a 5 minutes on, 5 minutes off cycle. The volume is only about 16 quarts, so it will ramp up pretty quick for mash out. Confirm that it takes about 180F to bring the mash to mashout temp in a reasonable amount of time.

Also confirm that the thermal blanket effect is significant, and some sort of mixer would be a good idea.