Water Heated Mash Tun design

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Well-Known Member
Dec 21, 2007
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Oconomowoc, Wisconsin
So I have been designing my system for quite a while now and am still kicking around creative ideas because it is fun to think about. Do you think a water heated mash tun would work?

Check out my sketch-up design:

Basically, a keggle is held in an aluminum pot with wood blocks to separate it from the aluminum walls. The aluminum pot has an electric heating element in it that is temperature controlled. All I would do would be to set my desired mash temperature and let it go. I would also circulate the water in the jacket to maintain an even heat.

I don't think this would be a fast way to heat up water, so my plan was to heat my strike water in my HLT and drain it into my mash tun. Then add grains to preheated strike water. All the water jacket would do would be to maintain accurate mash temperature and possibly step mashing.

My question is, would the water be able to add enough energy to the keggle to do a step mash? I am not sure off the top of my head and don't feel like going to equations to figure it out. If you have an opinion chime in.

I am just not convinced that the recirculating mash systems are the best way to go. I may end up there anyway, but I am looking for alternatives first. This setup would not cost much more than a recirc setup and may be better because the wort would be seeing no temp fluctuation (macro or micro).


not sure if this attachment will show up...

nope didn't work, I really need a premium membership. Must convince my wife tonight, or soon anyway...
The only flaw is the application of heat only to the perimeter of the mash. RIMS/HERMS works very well to keep the entire mash at an equal temp. Personally I think it's a waste of a nice big aluminum vessel. You'd be better off direct firing the mash tun and if getting a pump for RIMS/HERMS is a stumbling point, you can manually stir the mash when applying heat.
I direct fire my mash now and it works well, but the temp does fluctuate about +/- 3 degrees during my mash. This is no big deal, I just like kicking ideas around. I also think this may be way overkill for a minimal return. Perhaps a good insulation jacket is what I need. That would probably be cheaper and do the same thing as the water.