How do I HERMS?

[jceg316]

I have upgraded my plastic mashing/kettle buckets to a stainless steel one and I thought I'd get a pump as well so I could make a HERMS system and use my wort chiller as a coil submerged in my kettle.

I've done a lot of research on HERMS but there are a couple of things I'm not really sure on, like when do I actually turn the pump on? Do I need to let the strike water sit in the mash tun with the grain for a bit before I start circulating or so I turn the pump on straight away after dough-in is complete?

With the return pipe, does it need to go below the water level in the MT or just on top?

I have some more questions but I won't ask too much right now.

Thanks in advance.

 

[acidrain]

You can start recirculating immediately. The trick is to start slow, and not get too much suction going on the grain bed so that it doesn't compact and become stuck.
I typically don't start recirculating right away. My thought is there is no reason until temps begin to drop, so I usually wait 10 or 15 minutes.
As for the return, a soft hose laying on the surface, or a way to sprinkle it evenly is best.

 

[jceg316]

Hey Acidrain thanks for your response. When you first got a HERMS did you do a practice run with just water to "calibrate" temperatures between the HLT and mash tun? And if so did you find there was a difference between using only water a day then adding grain?

 

[cantrell00]

Hey Acidrain thanks for your response. When you first got a HERMS did you do a practice run with just water to "calibrate" temperatures between the HLT and mash tun? And if so did you find there was a difference between using only water a day then adding grain?

The temps in each find a equilibrium in each scenario. Grain behaves the same as water in this regard.

As for measuring the temp of the mash, I have found that placing the probe at the MLT return to be the place where the least amount of temp variance between the HLT/MLT to occur.

Typically a 3 degree differential.

 

[jceg316]

My heating controller broke so I can't set up my HERMS until that's fixed now. Will probably work on a brewpi but that's another story. Anyway, someone sent me this link: http://www.philrobins.org.uk/ a British homebrewer who has made a HERMS system and seeing the pictures on his setup as well as his explanations have also been really helpful.