Insulated Mash Tun - Vacuum Insulated?

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Well-Known Member
May 18, 2017
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I have seen a number of insulated, stainless steel mash tuns available for purchase, but it seems like none of them can be directly heated. I'm not sure why, but I assume it is either because (1) the insulation used is not heat-proof (foam, for instance), of because the bottom is insulated and the contents of the pot simply wouldn't be able to heat.

This got me thinking: What about a stainless steel mash tun with a solid bottom, an insulated lid, and double-walled vacuum insulated sides? It would essentially be a big Thermos with a solid bottom.

A tun like this could be directly heated to a chosen strike temperature via the solid bottom, and kept (relatively) temperature stable thanks to its vacuum insulated side walls and insulated top. The only significant heat loss would be through the bottom, and that could be mitigated by making the tun taller and more narrow (thereby reducing the bottom's surface area), and the ability to reheat (in the unlikely even that it were needed). Later, the tun could double as a boil pot, which would be especially handy for BIAB, full volume mashing and people using mesh filters in lieu of a false bottom setup.

What do you guys think? Good idea? Does anyone already make a direct-heat, insulated mash tun?