I've just started a mash and the temp was bang on 70c, I turned off the power to the tun, left my thermometer on while adding the grain. As I came to the end the temp shot up over 80c, I've never seen a rise like this before. The only thing different about this brew is that I've added 500g flaked barley, could this have some reaction to cause the heat to rise??? I'm utter befuddled!!!!! Update: I'm adding cold water every 5 mins as the temp is rising...This is soooooo bizzare!!