I have upgraded from a cool box mash tun to a thermopot, and I have a daft question on mash tun temperatures.
I have a 5L S/S HEX pot fitted with a kettle element controlled by a PID. I monitor both the exit temperature of the HEX and the output from the mash tun. The pump recirculates the wort between the HEX, and returns it to the top of the mash tun.
The temperature differential between the mash tun and the HEX was only 0.2 degrees C using the rectangular cool box, as the grain bed was relatively thin. Now using the thermo pot the grain bed is considerably greater than the cool box.
The temperature differential is now 1.5 degrees C.
Today on a brew, I set the HEX output to be 67 degrees, (I wanted to mash a little higher on this particular beer). The output from the mash was 65.5 degrees C.
Question: If wanting a higher mash temperature, ie 67 degrees C. Do I use the output of the mash tun for this?
If so, then the HEX temperature would need to be around 68.5 degrees C for the grain bed to see it at the exit of the mash tun.
Which is the most important temperature to monitor in this situation, the HEX output, or the mash tun
Any advice from the more experienced HERMS brewers would be most appreciated.
Best regards,
WM7793