Brew temperature

The actual water temperature meeting the coffee in the puck during extraction — not the same as the boiler temperature or the machine's display temperature.

Why it matters — Brew temperature is the most influential variable for extraction speed. Higher temperatures extract more compounds faster (including sour-acidic and bitter compounds); lower temperatures pull more slowly and produce a smoother, sweeter cup.

Good to know

• Typical ranges: light roasts 94–96 °C; medium 91–94 °C; dark 88–92 °C.
• The "set point" on a PID is not the same as brew temperature — there's always a few degrees of loss between boiler and puck. Saturated groups are closer to set; E61 groups vary by warm-up state.