Mash tun temp question

[Will_D]

Just thinking at loud here aswell what about a stainless mash tun, keg, pot, whatever inside a larger pot. the outside larger pot filled with water and a kettle element in there regulated by a PID. would the mash stay the same temp as water next door?

The problem with a mash is called "Thermal Conductivity" Water is not a great conductor of heat. However water in a boiler moves ( due to convection currents ) and so the heat is distributed thoughout the liquid. This is fine for boiling water and your wort.

However, A mash cannot move much and so any external heat will just raise the mash nearest to it to a too high temperature while the bulk of the wort stays at a fairly constant temp.

Constant stirring would be needed and a lot of people don't like to constantly stir.

The only real options are to either recirculate the wort via a RIMS or HERMS system or as has been mentioned, probably the best way is direct steam injection.

A question you need to ask yourself is "Why Bother?". Modern malts do not need the older fashioned stepped temp mashes!

Just hit the correct temp for your amylase for your brew

[johnrm]

I have something very like this...
http://www.walmart.com/ip/McCulloch-Handheld-Steam-Cleaner-MC1226/16571807?findingMethod=rr

I picked it up in B&Q some time back and use it for Steam sanitising bottles.

I reckon a bit of tubing off this could just work to heat up a mash.

Worth a shot.