Why is sun tea flavor typically described as smoother than hot brewed tea?

Slow, low-temperature extraction prevents the quick release of bitter compounds.

The characteristic smoothness attributed to sun tea arises directly from the low-temperature extraction facilitated by the sun's ambient energy over several hours. When tea is steeped too quickly or too hot, as happens with boiling water (which reaches nearly 212°F or 100°C), certain compounds like tannins are released rapidly, resulting in a bitter flavor profile. The slow warming process inherent to sun tea operates in a vastly different thermal space, gently extracting compounds over time. This gradual process specifically prevents the swift release of the bitter elements, leading to the mellow taste that enthusiasts prefer, which contrasts sharply with the quick release achieved during a standard hot brew.