Serving temperature changes a wine more than many accessories. Too cold: it falls silent. Too warm: the alcohol steps forward and the fruit blurs.
A brief house guide
Whites and rosés: 7 to 10 °C. Young reds: 14 to 16 °C. Aged Monastrell and reserva: 15 to 17 °C. The “room temperature” of a flat in August will not do.
An honest trick
If the red is warm, twenty minutes in the fridge. If the white is iced, five minutes out. The glass in the hand will do the rest.