My perspective/take on pot for HERMS

[london_lhr]

Hi all,
first of all my total brewing experience is zero, nothing, zip, nada pints brewed.
I read with interest the other thread about building a pot for HERMS. (Great build by the way.)
I would like to suggest another and possibly more cost effective way to do HERMS.
No pots or heating elements and only need some copper coil/tube.
(This is how I intend implementing it in my own electric brewery. )
You would need to coil some copper tube, similar to your immersion cooler or some lenghts of straight, 22mm copper tube to make up something similar.
I assume you already have two pumps in the brewery.
You could probably use your immersion chiller and in stead of cooling, it is heating in this application.
This is put inside your mash tun. Connect the inlet and outlet via your water pump to circulate water from the HLT and control the pump with a PID and probe connected to the mash tun.
This can also be used to agitate or "stir" the mash?
The HLT water temperature is controlled by it's own PID controller and the temperature set for the HLT water should be higher than the temperature needed in the mash tun ie. mash out temp?
You can connect your wort pump to recirculate the wort from the mash tun back to the mash tun.
This wort flow over the temp probe will give an accurate temp of wort in the mash tun.
It will also make incremental mash temps easy to achieve.
This way you are circulating water through the coil and not wort.
Easy to sanitise/sterilise outside of this copper coil and no problems to clean wort/stone etc. from inside the coil.
The silicone tubing for recirculating the wort is easy to clean and sanitise/sterilise or even replace!
In my planning I planned a PID probe connected to the mash tun to display temperature only (more cost effective than the shiny ones!)
This way I can actually use the PID in the mash tun to control the water pump!
Please bear in mind that my brewing experience is nada and I would welcome the voices of experience to point out the flaws in my reasoning.

Barry.

 

[PD]

I'm not a herms man myself..... but it seems to me that in your case the heating effect of the water in the coil would be very localised ( around the copper coil ) outer areas of the mash would not receive the same heating effect.

 

[london_lhr]

Thanks for your input, PD.
The mash tun is very well insulated and I don't foresee massive heat loss.
Also, I think the 22mm copper tube would be better as it has a greater surface area.
The wort is being re-circulated through the mash tun all the time. It is not static.

Barry.

 

[adomant]

Not tried it myself so have no idea, but see no obvious reason why it won't work. The heat transfer may be less and it could be that the the lag in doing a large step in temperature might be substantial, therefore the mash surrounding the coil may get hotter than the probe reading which could lead to enzyme denaturing e.g to get the mass up to a uniform 67c in a reasonable timeframe the coil may need to get up to 80+ over a prolonged time. Would love to know how it actually works though.

 

[AndyW]

Your idea sounds a lot like this:

http://byo.com/stories/projects-and-equipment/item/2799-build-a-heated-mash-tun-projects

I think there is a previous thread on the topic.
I have not tried it and have no direct experience but I am quite interested in the approach. I also see the problem might be how to dissipate the heat into the bulk of the mash.
Andy

 

[pittsy]

isn't this rims system ?

 

[Vossy1]

Welcome to the forum Barry :thumb:
You mention the use of 2 pumps, one possibly recircing the mash and one recircing liquid from the HLT to heat the mash. I see no problem with this, though the thermoclines within the HLT will take some learning from the pid and I have to ask if that'll be within the 40 mins or so of the malt conversion process.

This is put inside your mash tun. Connect the inlet and outlet via your water pump to circulate water from the HLT and control the pump with a PID and probe connected to the mash tun.
This can also be used to agitate or "stir" the mash?

Are you suggesting you could move the coil around in the mash to stir it and evenly distribute heat? If so that would make it very difficult for the mash recirc pump to work as it would almost certainly 'stick' the mash with frequent movement, not to mention defeating one of the objects of this type of system, a clear run off, though naturally this could be negated by not stirring in the last 15 mins or so.

It will also make incremental mash temps easy to achieve.

Not really. Using a RIMS system you're using direct heat, to heat the wort, with a HERMS your using minimal volume heat exchange liquid to raise the entire mash temp . Using a HLT means heating a larger volume of water in order to heat the mash which is inefficient and will take longer, unless you have a massive heat input to liquid ratio for the HLT, in which case it possible but probably very inefficient.

Easy to sanitise/sterilise outside of this copper coil and no problems to clean wort/stone etc. from inside the coil.

You don't need to sanitise the coil in a HERMS/RIMS system...only clean it...everything post mash is boiled.
'Stone' is usually only a problem in the fv (time in fv) or boiler (reaction/evaporation in the boiler), not in a HERMS or rims set up, it doesn't have the time to settle or the conditions to stick.

This type of system also means one extra thing (over my system and possibly others), cleaning and removing the coil from the mash. I say one extra thing because depending how you set up a HERMS system ( and possibly RIMS) you can use the pipework to feed the sparge liqour to the mash, meaning no cleaning of the HERMS pipework is required.

Let us know how you get on.

 

[london_lhr]

Thanks for the replies :

 

[adomant]

depending how you set up a HERMS system ( and possibly RIMS) you can use the pipework to feed the sparge liqour to the mash, meaning no cleaning of the HERMS pipework is required.

Thanks for this Vossy, I have changed from a gravity fed sparge to switching the herms input to the sparge liquor vessel on a recent brewday. This gives the benefit of monitoring and some control of the sparge temp via the herms pid, constant sparge flow rate and clean herms equipment afterwards.

Good tip, worked for me :thumb:

 

[Vossy1]

Glad it's worked for you a , it's nice to get some feedback :thumb: