1st time HERMS difficulties

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Eclipse9101
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1st time HERMS difficulties

Post by Eclipse9101 » Sun Jan 17, 2016 9:50 pm

So I tried HERMS forthe1st time over the weekend. The brew was a mosaic pale ale. Target mash temp was 65, so I had my pid set to that (the pt100 was in a t piece on the coil output return to the top of the mash tun. I had a thermometer in the centre of the mash tun to compare this to the target the pid was maintaining. I underletted at 66 degrees and immediately started the recirc, I monitered the mash temp and it slowly increased until it reached 62 degrees. Throughout the whole 90 minute mash the pid kept the wort return bang on 65 degrees. But this was never reached in the centre of the mash itself.

Im not sure if I did something wrong here but was hoping someone with a bit more experience of herms could give me some advise me. This was the worse brewday I've had and a lot of numbers were missed. I'm sure herms is brilliant but just need some advice on how to get everything working right.

Cheers
Last edited by Eclipse9101 on Wed Jan 20, 2016 6:06 pm, edited 1 time in total.

Lockwood16

Re: 1st time HERMS difficulties

Post by Lockwood16 » Mon Jan 18, 2016 4:35 pm

Hi Eclipse9101, sorry to hear about your HERMS problems. I initially had one or two temperature issues and other problems to overcome myself. Now everything is sorted, I am very pleased with it's performance.

Your PID controller seems set up correctly to maintain mash temps, so no problem there.
I have fitted another PT100 on the "T" exiting the mash tun measuring the grain temperature. After first calibrating both PT100's to ensure accuracy of both probes, I now have approx 1 degree centigrade of thermal gradient in my mash tun, so it's puzzling why the grain bed is not reaching your desired temperature.

Have you checked the accuracy of your thermometer in the centre of your mash tun?
Is your flow sufficient from your pump to maintain temperatures?

Best regards,
WM7793

Fil
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Re: 1st time HERMS difficulties

Post by Fil » Mon Jan 18, 2016 7:41 pm

Try a strike temp closer to 70-72c for the underlet the grain absorbs some heat and will cool the bulk down closer to the target temp,

as your recirculating you can afford to give the mash a stir or 2 to ensure the mix isnt channelling the return straight down to the exit/drain.. the grain should reform a filter bed fairly rapidly..

stick with it and it will all fall into place .. good luck ;)
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

Eclipse9101
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Re: 1st time HERMS difficulties

Post by Eclipse9101 » Mon Jan 18, 2016 10:16 pm

Cheers guys. Some sound advice there. Im hoping my next herms brewday will be with my new thermo lot tun which has a false bottom rather than a copper slotted manifold.

I'll also have a tinker with my pid and see if I can calibrate the pt100 probe.

Fil
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Re: 1st time HERMS difficulties

Post by Fil » Tue Jan 19, 2016 9:50 pm

iirc page 16 onwards in this thermometer manual describes a close to 0C and close to 100C 2 point calibration test ..http://docs-europe.electrocomponents.co ... ddbbe8.pdf
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

guypettigrew
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Re: 1st time HERMS difficulties

Post by guypettigrew » Wed Jan 20, 2016 4:21 pm

Eclipse9101 wrote:I had a thermometer in the centre of the mash tit
Sounds like an interesting piece of kit!!!!!!!

Guy

Matt in Birdham
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Re: 1st time HERMS difficulties

Post by Matt in Birdham » Thu Jan 21, 2016 7:27 pm

How are you returning your wort to the tun? Are you using some kind of manifold, or just putting the hose straight in? If the latter, then you are probably channelling pretty badly. I use a very simple return manifold which is made of 1/2 inch, thick walled silicon tubing that is looped around to join a copper T. Holes are drilled in the tube and I have it with the holes pointing upwards, resting on top of the grain bed. This works very well, and when I probe around the mash with my thermapen I am rarely more than 1C away from my target temp.
As others have already said, also worth making sure both your probes agree on temps. What pump are you using?

Here's a pic of my return - I slide it up and down to fit the volume I am mashing:

Image

Eclipse9101
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Re: 1st time HERMS difficulties

Post by Eclipse9101 » Fri Jan 22, 2016 10:04 am

That a very good point about the channelling! I hadnt thought of that. I've just completed my thermo pot mash tun and this has a false bottom. Do you think this will mean no channeling? Even if I still lay the return hose ontop of the grain bed?

I'm hoping to have another brewday either today or this weekend. All depends if I can figure out where to store my kegs as I'll need the fermenting fridge for it!

Oh and the pumps I'm using - they are 24v mag pumps rated to 100 degrees c food safe. They were about £12 each delivered from within the UK on eBay. Absolute bargain! Think they are TE92 if you search for that it should bring them up.

Matt in Birdham
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Re: 1st time HERMS difficulties

Post by Matt in Birdham » Fri Jan 22, 2016 11:06 am

Eclipse9101 wrote:That a very good point about the channelling! I hadnt thought of that. I've just completed my thermo pot mash tun and this has a false bottom. Do you think this will mean no channeling? Even if I still lay the return hose ontop of the grain bed?
I really think it's worth making some sort of return manifold - especially as your pump sounds like it would have a decent flow rate. Doesn't need to be complicated, just something to gently distribute the returned wort over the surface of the grain bed, and you can make one like mine for literally a couple of quid and a few minutes work.

Eclipse9101
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Re: 1st time HERMS difficulties

Post by Eclipse9101 » Fri Jan 22, 2016 11:09 am

Cheers mate. Will probably do that. Would a piece of tin foil with holes in it work in a similar sort of way until I can get the bits together to build one?

Eclipse9101
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Re: 1st time HERMS difficulties

Post by Eclipse9101 » Sun Jan 24, 2016 5:02 pm

So I did my 2nd herms brewday on Friday. This time I used my newly completed 50 litre thermo pot false bottom mash tun. It was a much better brewday than I had previously. A couple of things not quite perfect though. The pid was set to a mash of 66 degrees this time. I heated the strike temp to 74 and underletted. This brought the mash to bang on target of 66c. After a couple of litres recirc with a jug I started the herms. Monitoring the centre of the mash tun with a separate thermometer this indicated the centre of the mash was 65 degrees exactly throughout the 90 minutes. Exactly 1 degree below what my herms return was indicating on the pid. I think this was OK? By the end of the mash I ran my sparge water back through the herms coil and set the pid to 75.6. This worked brilliantly! I could let the hlt temp slowly drop and the pid ensured the sparge water entering the mash tun remained bang on sparge temps! With the added bonus of the hot water cleaning out the coil. For the herms return to the tun I used a piece of tin foil and layed the silicon tube ontop of this. Semed to work well with no indication of channelling this time.
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HairyJamie
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Re: 1st time HERMS difficulties

Post by HairyJamie » Mon Feb 15, 2016 10:02 pm

I'm considering a HERMS set up myself Eclipse9101, just drooling over stainless steel catering tables at the moment!

I've been puzzling over how to mount my pumps though - I have the mini mag types as I think you do. Any chance of a description of your mounting solution and some pictures?

Cheers,

HJ

Eclipse9101
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Re: 1st time HERMS difficulties

Post by Eclipse9101 » Tue Feb 16, 2016 9:32 am

Hi mate. Mine are just mounted into a spare bit of wooden shelf I had lying around. I basically just drilled a hole a touch smaller than the diameter of the pump body and used the dremmel to slowly widen it until the pumps were a snug fit. Simple solution really as the pumps themselves don't have a physical bracket to mount them to anything. Hope this helps. I'll try and find a couple of pics for you.
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HairyJamie
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Re: 1st time HERMS difficulties

Post by HairyJamie » Tue Feb 16, 2016 1:39 pm

Thanks - looks a nice neat solution, I'll have to dig out my hole saw set and give it a go.

It's annoying that there isn't a better mounting solution or bracket for mag pumps, I have the Munson clip style ones but they're just not sturdy enough if you have a ball valve on the output.

Fil
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Re: 1st time HERMS difficulties

Post by Fil » Wed Feb 17, 2016 12:33 am

i would pull the keyrings and slip clips off the camlock levers @eclipse9101 i found them to be quite a nuisance ;)
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

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