Thanks for the quick response!
I do have access to electricity. For heat, I brew on natural gas at home on my back deck.
RIMS seems like it might be a little too complicated for me at this stage.
Well, it's not going to be any more complicated than a HERMS, but if you already have the BK and can use that, it'll be cheaper than getting a control panel and RIMS tube and element.
The downside to HERMS is it's not all that responsive, i.e., if you want to move up your mash temp, you have to heat the water to do that, and then there's that delay. RIMS is fast, at least in my system. The downside to RIMS is the expense if you already have some of the HERMS equipment. Some also are concerned that RIMS can scorch the wort, but if you start pumping through the RIMS tube, and have good flow, that really can't happen.
Sometimes best to work with what you've got. I went with RIMS because I wanted to play with some step mashes and wanted the ability to control my mash temps to within a degree, and it does that. But if you can insulate the mash tun well and hit your initial mash temp, then it's not all that necessary.
FWIW, I have my mash tun sitting on some foamboard insulation so the bench it sits on isn't sucking heat out of it. If I were doing insulation, I'd probably take an old sleeping bag or thick blanket and sew it up so it fits over the mash tun well, sort of like a glove. That makes putting on and taking off easy, and that was always the deal for me--wrapping with a thick blanket is not as quick.
HERMS sounded appealing since I already have a pump and could utilize the extra volume in my BK to keep warm wort pumping through the system, or maybe use it to perform step mashes(?) but if it's not very effective with this sort of setup then maybe low tech is the right solution. In what situations/setups would you recommend a HERMS?
I think part of the fun of this hobby is figuring this stuff out, and creating capabilities with which we can experiment. There's nothing wrong with HERMS--it's just a different way to heat the wort as it pumps through what is essentially a heat exchanger.
In your case, you could set the HERMS water at the mash temp you're targeting, set it to flow, and it would maintain that temp pretty well. You'd still want to insulate the mash tun with something, but once it's going, you could leave it for 90 minutes and not have to worry much about it.
If there's a downside to using your BK for this....if you're recirculating you should be able to pull very clear wort off the mash tun. In my case, I just switch the hose that runs the wort through the RIMS tube to the valve at the bottom of my BK, and fill it up. You'd have to drain the BK first, obviously. But the filtering of the grain bed should give you very clear wort and all you need do it get that pumped into the BK.
If you have the HERMS tubing, there's nothing to lose in trying this--and you should, before considering anything else. Heck, a cheap immersion chiller could be used for this. I have a stainless one, it'd be perfect for this kind of thing.
Maybe the sleeping bag or some kind of custom styrofoam box that I can slip over it during the mash is all I really need.
Sometimes we overthink this. Just get the mash tun sitting on some foam, wrap with sleeping bag or similar.
But play with the HERMS idea. Why not?
Pic of my mash tun. I used wire on this one to hold the reflextix on, but I've also used aluminum duct tape as well for other kettles:
