I've been racking my brain for days on systems to control mash temps. Largely because I like lagers and wheat beers and even Palmer himself has multi temp mash schedules for these beers. http://howtobrew.com/section4/chapter19-4.html
, for example.
So, the idea would be to quickly add heat to mash to change the temps as the mash went on.
The question is how.
Infusions work, but the temp control isn't precise and if you miss its not easy to correct. One is also limited to the number of infusions one does before the mash gets too thin.
HERMS and RIMS systems are commonly used, but they rely on continually circulating the wort. I have a HERMS system myself. I have to admit that I am jealous of the infusion process where the mash just sits there cooking, with the occasional stirring.
So, what if we introduced heat into the cooler without circulating the wort ?
We could do this by embedded a copper coil in the mash and running hot water through it. But it would take a big coil and there would be hotspots and it would severely get in the way of of stirring. Also it would create channels if we were still circulating the wort and it would have to be removed prior to sparging.
We could put electric elements right into the wort, but usually their power density is so high that they would scorch the wort and they would be in the way for stirring, etc.
So, what if we converted a cooler to be an insulated water bath, like this:
Basically take a dremel tool and cut a path around the perimeter of the cooler to separate the inner liner from the outer shell. Then plumb in an inlet and outlet fitting into the shell that does not go through the liner. Then remove a bit of insulation everywhere to create a space for the water to flow from inlet to outlet. Then put the cooler back together, possibly using an adhesive to hold it together.
This would allow hot water to be circulated against the liner, thus warming up the cooler and the grain bed.
One would add a small vessel with a heating element to warm the water and a pump to circulate the heated water.
So... has anyone ever cut a cooler apart ?
Is the insulation bonded to the liner or the shell or both ?
Would a cheap cooler happen to be built without any insulation between the liner and the shell ? Aren't some of the lids like that ? A hollow cooler would be very easy to circulate water in.
If running the water between the shell and the liner is too extreme, one could route a ton of copper tubing between the two and run water through it.