Just had a go at underletting my mash this morning, not single vessel, I have a 3V setup
HLT water at 59 C, filled tun to false bottom, goods in, added the rest of the water, 18 L total.
Mash temp was 48 C so warmed with HERMS to 54 in about 15 minutes, it's resting at 68 now.
I stirred to...