HERMS - What Temp Differential Do You Use?

[nealperkins]

I have a HERMS set up. The recommended temperature differential (MoreBeer) was/is 10 degrees.

The problem is that because the pump may be off for 20 minutes, the wort in the tubing cools to ambient. When the pump comes on, the 'heating' phase begins with a cool down and finally an overshoot when the target temp is reached.

So, I'm wondering if I set the HLT to 1 or 2 degrees above mash temp and let the pump run continuously if I could maintain the temp better.

Better than that would be . . . learning from your experience! So, how do you use your HERMS (as in temperature differential from HLT to mash temp.

 

[Scut_Monkey]

I'm still in the process of building my HERMs so my thoughts below are just that.

I would imagine running the pump continuously would be best with the differential set at or near the desired wort temperature. This would, like you mentioned, eliminate the cooling wort in your lines. Additionally, if you are recirculating during the entire 60 minutes you may end up with a clearer wort at the end which is one of the advantages and reasons behind a recirculation mash.

 

[nealperkins]

Bump.

Come on guys...I know there are a bunch of HERMS systems out there.

 

[restill]

I've only used my HERMS a few times since finishing it. I need about a 15 deg diff. I leave the pump running and control the heat in the HLT. It takes a while for the temp to change in the MLT, but a bit of planning, observation, and adjustment on my part seems to work OK.

I am going to shorten the length of tubing between the HLT and the MLT to slow the cooling in the line.

It's all one big experiment.

 

[devilishprune]

I don't have a HERMS yet, but I'm in the design process on my system. It was my understanding that you were supposed to run the pump the entire time to ensure that the wort was all at a consistent temperature.

 

[sambogi76]

I'm in the process of putting mine together (waiting on some more parts). But do you have any insulation on your MLT? I have decided to do this to help maintain my temps better, and to be able to raise the temps up faster since I shouldn't lose as much with it being insulated. But like I said, I don't have one yet and this is just my theory.

 

[Yooper]

I use a three degree differential. My HEX is copper, and in the HLT. I keep it at 156 if I want a 153 mash. I use a cooler MLT, which holds the heat very well. I run it continuously.

 

[nealperkins]

Thanks Yooper, I was thinking (wondering) if 2 or 3 might be it. So, that's where I'll start. I've got a starter working for the next beer...make this one a Kolsch.

 

[DBbrewing]

I have only used mine 1 time so far, today will be the 2nd time and will see how it works today.

 

[rockytoptim]

I use a 1 degree differential. For 154 mash my HEX out is 155. I have a cooler as a MLT.

 

[DBbrewing]

Looks like my MT only dropped 1 degree in 30 minutes, thats when I turned on the pump to bring the temp back up(in the MT) and it took 10 degrees over(IN THE HLT) the mash temp to keep it at 150 degrees(in the MT), so for me it was 10 degrees over(in the HLT) and I got 85% efficience the highest I ever got.

 

[nealperkins]

If I did what you did...first my mash temp would have fallen by 3-5 degrees as the cold bolus worked it's way through; followed by a rapid increase usually resulting in a (usually) 3 degree overshoot. Of course stirring can change these results as well as a successful anticipation of events.

 

[trent]

I have a cooler HTL and cooler MTL with a chugger. I use a 5 degree diff. I think I have more tubing than others.