external herms(for want of a better title)

instead of having a copper coil in my hot water kettle i'm thinking of wrapping the copper externally around my mash tun ,insulating over the top of this and recirculating water from the lauter tun to maintain temps.

has anyone else tried this?
was it successful?

my reasoning is that there is less to clean and i can use any old pump from a dishwasher etc that i can lay my hands on.

i'll have to manually vorlauf but its not exactly the end of the world as i see it.

and comments, suggestions,critisisms?

cheers, martin

My understanding of the HERMS advantage is that you're actually recirculating the entire amount of wort so the average temperature of the system becomes the exact temperature of the wort.

I don't see any advantage to your system over a conventional insulated mash tun, other than you could raise temperatures (probably very slowly) but the mash temp could still vary within the mash tun itself ( I think likely cooler in the center, hotter out near your coils.)

hmmm... so a jacketed mash tun...

I think it would work but I don't think that would be a "herms" system. That would simply be a jacketed mash tun instead of an insulated one.

If you are simply looking to maintain temp, I think it would be a ton easier to just insulate the MT and it would be just as efficient as jacketing it without any of the headache or expense. If you're looking to step temp with it... then... I don't know... it doesn't seem like an efficient way to raise temp.

i know it wouldn't be a herms system, i just couldn't think of a better term,
i have the copper lying around already so the cost isn't a factor, i'm just exploring alternatives i suppose, cleaning is by far the least enjoyable part of the whole thing so i'm trying to keep it to a minimum

my mashtun (in fact, all kettles and fermenters) will be insulated with 50mm (2 inch)extruded polystyrene(free offcuts from work) and maybe, if i get motivated enough, finished with cedar, do you think this alone would maintain temp enough through the mash period?

i could always sell the copper to pay for other items

Ya figure normal everyday coolers keep temp with usually only losing a degree or two, if that... so I think it would work.

I would try that before going through the trouble of jacketing the MT with the copper, hooking up the pump, etc.

Step mashing with an actual herms is slow enough as it is. You will not be able to raise the mash in any practical amount of time. As others have said, it might only be marginally better than just putting some good insulation on your mash tun.

I would twist that coil up into a whirpool immersion chiller (a la JZ). You can use it as your herms coil during the mash, and your chiller after the boil. You can configure your system so that only one march pump (a la a B3 1550) will be necessary. Don't waste your time and effort with the external coil idea....


Mylo

Mylo said:

Step mashing with an actual herms is slow enough as it is. You will not be able to raise the mash in any practical amount of time. As others have said, it might only be marginally better than just putting some good insulation on your mash tun.

Mylo

Click to expand...

i was actually thinking of it just to maintain temps rather than step mashing, i knew it wouldn't have the power to raise temps appreciably.

as for the march pump- its on my list its just not that cheap to buy one in nz or have it shipped here and i'm taking a gently gently approach at the moment with regards to spending money so as not to alarn my other half too much!!