Herms System Build

Hello there, I've been following this forum for a long time, but this is my first post.

Currently I all grain brew with Sanke's for my HLT and Kettle, and a 60q cooler for my MLT. I've just purchased (legally through Widmer) a 3rd Sanke to replace my MLT. I've got 1 chugger and an IC and my heat source is exclusively propane.

I'm looking to gradually move toward an electric, automated HERMS set up. I am thinking of adding a PID to monitor my Mash temp and turn on/off my chugger which will pass through a HERMS coil in my HLT.

Here is my question: How important is it to control temperature in my HLT when trying to maintain mash temp through the HERMS coil?

For example, if I don't have a PID to control the temp of my HLT and I just manually heat the HLT, does my HLT temp need to be exactly the same as my target mash temp?

Even more specifically, lets say I want to mash at 152, and my HLT is at 170 for my mash out temp, is that going to be a problem?

Thanks!

Why not just use the pid for hlt temp and leave the pump running?

I think 170 will be an issue. Where do you plan on measuring the mash temp?

Quick answer is yes (and it's critical). The purpose of the HERMS is to use the temperature of the HLT to control and maintain the temp of the mash. Most folks use temperature feedback (PID) connected to an electric element (E-HERMS) or a propane burner circuit to regulate the temp of the HLT. The recirculating pump usually runs continuously. All that said, if you are unable to tightly regulate the temp of your HLT, you won't have much luck regulating your mash temps. Easiest solution IMHO is just install an electric heating element in your HLT and control the temp of the HLT with a PID loop.

+1 to what PLOVE said. The intent of a HERMS system is to have the mash follow along with the temperature of the HLT.

This works very well for brewing. You asked about having the mash at 152F but the HLT at 170F for mashout temp but you're not going to want to do that. What I do is mash for whatever period you want, using whatever mash schedule you want (single infusion, or step).

When your mash is done, you turn the HLT PID up to 168-170F mashout temp and the mash temp follows. No need to touch or changing anything other than turn up the HLT PID temp. Once the mash reaches that mashout temp, you start sparging.

I also have a PID that only monitors the temperature of the wort coming out of the mash so that I know when the mash has reached the target temp (since the HLT will always heat faster).

I have a video of the mashout here that shows how this works:



Kal

Kal

Nice video Kal! I certainly studied your system extensively when I was designing my own. Very elegant.

blur - Kal's description of how use the HLT to control mash/mashout temps is spot on. The only difference between between his system and mine is that mine uses a BCS-460 and programming steps in place of PIDs. Works the same, and once you get the steps down it's both intuitive and easy to control your mash temps.

Good luck!