Preheating is the cheapest improvement available to most brewing setups.
The heat loss
Water at 96 °C leaving the kettle passes through a room-temperature dripper, a room-temperature paper filter, and drips into a room-temperature carafe.
Measured at the bed, the actual brew temperature can be 5 to 8 °C lower than the kettle reading. A ceramic V60 is a substantial thermal mass.
That is the difference between properly extracted and sour.
What to preheat
The dripper, by rinsing with hot water. The paper filter, at the same time — which also removes papery taste. The carafe or cup, especially if the brew will sit in it. The French press beaker. The AeroPress chamber, briefly.
Discard the rinse water before brewing.
Espresso
The portafilter should live in the group head between shots. A cold portafilter is the main reason the first shot of the day tastes different.
The cup. A 30 ml espresso into a cold ceramic cup loses temperature immediately. Most machines have a cup warmer on top; it is there for a reason.
Ceramic versus plastic
Ceramic and glass hold more heat and therefore steal more from a cold start. Plastic drippers have less thermal mass and are more forgiving without preheating.
That is a genuine argument for plastic, and the reason many competition brewers use it.
Last reviewed 8 August 2026