How do I HERMS?

A forum for those who boldy recirculate where no man has. .... you know the rest
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jceg316

How do I HERMS?

Post by jceg316 » Fri May 22, 2015 11:36 am

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.

Lockwood16

Re: How do I HERMS?

Post by Lockwood16 » Thu Jul 02, 2015 9:09 am

Hi jceg316, not logged on for a while, and noticed no one has replied to your post.
I will try to give you some of my own experience with HERMS, for what it is worth.

I went a slightly different route. I made a separate HEX coil fitted inside a small 5L stainless steel pot, fitted with a kettle element. The wort was then pumped through the HEX and back into the top of the mash tun. The kettle element of the separate HERMS pot was controlled by a PID controller, with PT100 temperature probes measuring the exit of the HEX coil and mash tun. The system works very well, and is very responsive to small increments in temperature changes.

To answer your question. After mashing in, I can switch on the pump straight away, usually throttling it back to get it circulating and then allowing it to flow at full speed once I am certain there will be no stuck mashes. I did get them on my first try with HERMS, but I have fitted a number of filters to prevent this.

I return the flow to a drilled copper manifold at the top of the mash tun which sprays the grain bed.

If I can be of further assistance,do not hesitate to ask further questions. I have asked plenty when starting off!

Best regards,
Lockwood16

TheEarlOfMarquis

Re: How do I HERMS?

Post by TheEarlOfMarquis » Fri Aug 14, 2015 5:13 pm

Sorry to hijack the thread. I am thinking of going HERMs and just have a couple of questions. Is it an advantage to have a seperate vessel for the HERMs coil or could I just use the HLT with the sparge water in to heat the recirculated wort?
@Lockwood16 Could you tell me which PID model did you use please?
Thank you

Lockwood16

Re: How do I HERMS?

Post by Lockwood16 » Fri Aug 14, 2015 6:23 pm

Hi theEarlOfMarquis,

I bought a 5L stainless steel pot with lid, from ebay, (around £5), to have as a separate HERMS pot. I fitted a standard 2.4Kw kettle element at the side near the bottom, and then fitted a 10mm copper pipe coil inside of the HERMS pot, sat above the kettle element. The HERMS is then controlled by a cheap and cheerful Mypin PID (with SSR output) controller (around £10 each, last year). The wort is then circulated from the mashtun, into the pump, via the HERMS coil, and back to the top of the mash tun via a 12v DC pump (from Angel home brew).

I fitted a PT100 on the exit of the mashtun, and also another PT100 on the exit of the HERMS pot. Used one PID controller to fire the kettle element via a SSR, the other PID was to monitor the exit temperature of the HERMS before the wort returned to the top of the mashtun. With this small HERMS pot, the temperature rises around a degree a minute, which is quite acceptable, and works a treat. The differential between the mash tun exit temperature and HERM exit temperature soon equalises. Step mashes are easy with this system.

If I can be of any further assistance with wiring etc, etc, then let me know.

Best regards,
Lockwood 16

TheEarlOfMarquis

Re: How do I HERMS?

Post by TheEarlOfMarquis » Fri Aug 14, 2015 6:27 pm

That's great, thank you for the information. That's plenty to get me going :D

jceg316

Re: How do I HERMS?

Post by jceg316 » Wed Sep 23, 2015 9:08 pm

I just saw someone actually replied to this thread. I haven't been here for a while. Thanks for the reply, I'm thinking of making a HERMS pot. my only issue though is what to do about sparge water. I would not be able to heat 2 X 2.4 kw elements at the same time (one for the HLT and one for the brew pot). At the moment I'm running the wort through my chiller which is submerged in my brew kettle. I use a pump I found on ebay to circulate the wort. Once mashing is complete I take the hose off the end of the mash tun and place it onto the HLT and run sparge water through the chiller. This cleans the chiller and also pushes through any wort still in there.

The pump is the difficult bit. It's very sensitive but after adding a bleeder valve and ensuring it's oriented the right way up (exit above entrance) I have very few issues.

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