This discussion on shot temperature is fascinating. I just finished cupping Malabar Gold at various brewing temperatures and the difference (+/- 3 degrees F from my usual baseline) was dramatic. A cold vs a hot cup also had a significant effect on taste. To me, warm was obviously better than hot. It is interesting that in the finest espresso bars in Naples, Italy (lever machines only) the cups sit in a steaming water bath. To my knowledge, no one ever discusses if it's best to drink the shot immediately or wait for it to cool a bit. Assuming other variables are controlled, would there be a difference in taste extracting a shot into a cold cup and drinking at a given temperature or into a hot cup and allowing it to cool to the same temperature? Allowing the hotter cup to cool down may allow certain chemicals to evaporate prior to drinking. Whether this would improve or worsen the shot taste is unknown to me. Unless someone has feedback on this and can stop my foolishness, this will be my next experiment.