> Both espresso samples were served at 22 °C to ensure a fair like-for-like comparison […]
> It is noted that espresso is normally consumed hot and has transient sensory attributes that are temperature- and time-dependent. Hence, serving espresso at 22 °C will alter its sensory characteristics.
This is a weird test, coffee get’s so much worse when cold. So people can’t distinguish between two bad coffees.
"Good" (well-extracted) coffee is still relatively good when warm, especially compared to "bad" (over-extracted, or under-extracted) coffee. That said, many believe that the optimal temperature for serving coffee is 50-60 degrees celsius (122-140 degrees fahrenheit).
> coffee get’s so much worse when cold
Coldbrew is a thing and done right it brings out a refreshing sweetness. Also iced coffee. Bad coffee is bad hot or cold.
> coffee get’s so much worse when cold
This is a myth. Bad coffee tastes better when hot because your sense of taste is dulled - reducing bitterness. Also, at higher temperatures, aromatics and volatile compounds are more airborne, improving the smell of coffee. Good coffee is better enjoyed around 60-70C