I will never again start reducing a chicken stock that took hours to make, then get engrossed in some nonsense on the internet . The stock reduced OK - to a brown sludge on the bottom of the pan.
I will never again, having reduced stock to a brown sludge on the bottom of a pan, curse at it, turn off the heat and stomp out the house for an hour or two to do some shopping, only to return to find that I didn't turn off the heat at all , but turned the knob in the wrong direction and only reduced it to minimum. Cooking brown sludge for two hours on minimum doesn't help.