Water temperature
Hotter isn't stronger — it's faster — 4 min
Temperature does not make coffee stronger; it makes extraction faster and slightly changes what dissolves easily. Hot water is a better solvent for the sugars and heavier sweet compounds; too-cool water gets the fast acids and leaves the sweetness behind, which reads as sharp and thin.
The filter window is roughly 90–96°C. Boiling water is not the villain kitchen folklore says — for light, dense roasts it is often exactly right. Dark roasts are the ones that reward gentler heat: their cell walls are brittle and their bitter compounds come out easily, so 85–90°C keeps them from turning ashy.
Interactive
Drag the dial — match the water to the roast, not to a superstition.
Try it in the Blend app
You do not need a thermometer to use this lesson. Boil the kettle, then wait: about thirty seconds off the boil lands a typical kettle near 95°C, a minute or so near 90°C.
What matters more than chasing a degree is not losing ten of them by accident. Room-temperature glass or ceramic steals 5–8°C from the brew on contact — so rinse the press or brewer with hot water first. Preheating is the cheapest temperature upgrade there is.
Note
Below about 80°C, hot brewing stalls noticeably — yet extraction never truly stops. Cold brew works at 20°C by trading temperature for time: what 94°C water does in four minutes, cold water needs twelve hours or more to approximate. Same chemistry, different clock.
Brew it with a guided timer.
Blend counts the pour, times every step, and saves what you change. Free on iOS and Android.