Water is about 98% of what's in your cup, so its temperature makes a real difference. Too hot and you'll drag out bitter, harsh flavours. Too cool and the coffee comes out sour, thin and underdeveloped. It's one of the easiest things to fix at home.
The short answer
For most brewing methods, aim for 90 to 96°C, the range recommended by the Specialty Coffee Association. Hot enough to dissolve the good stuff, not so hot that you pull out the rest.
No thermometer? Boil the kettle and wait 30 seconds to a minute. That lands you roughly in range.
Why it matters
Brewing is extraction: water dissolving flavour out of ground coffee. Different compounds come out at different rates. Acids and fruit come first, then sweetness, and bitterness last. Hotter water extracts faster and further; cooler water extracts more slowly.
Temperature is one of four controls, alongside grind size, brew time and your coffee-to-water ratio. Change one at a time, or you'll never know which one worked.
Adjust for the roast
This is where our two roasting programmes come in, because they want different things from your kettle.
Our black coffees, the single origins roasted lighter for filter, are denser and harder to extract. They like heat: 94 to 96°C. A honey-processed Ethiopian like Sidama Gatta needs that heat to open up its papaya, vanilla and parma violet notes. Brew it too cool and the florals never arrive.
Our white coffees, the blends built for milk, are roasted a little further and give up their flavours more easily. Drunk black through a cafetière or stovetop, they're happier around 90 to 93°C. Joe's Green Balloon is a good example: at the cooler end you get the roasted walnut, nougat and chocolate without any scorched edge.
As a rule: the lighter the roast, the hotter the water.
Temperature by brewing method
- Pour-over (V60, Chemex, Kalita): 92 to 96°C. Go to the top of the range for lighter single origins. Try 15g of coffee to 250g of water, medium grind, over two and a half to three minutes.
- AeroPress: the most flexible of the lot, anywhere from 80 to 96°C. Cooler water gives a softer, sweeter cup, which suits fruit-forward coffees like Rocala. Our starting point is 25g of coffee, medium grind, 100g of water, one minute.
- Cafetière: 92 to 95°C. It's a long brew, so there's no need to push hotter. 30g coarse-ground to 500g of water, six minutes.
- Stovetop (moka pot): start with hot water from the kettle rather than cold. The coffee spends less time on the heat and is far less likely to taste burnt. 15g of coffee, fine to medium grind, 150g of water.
- Cold brew: cold or room-temperature water, 12 to 24 hours. Time does the work heat usually does.
Espresso is its own thing
Most machines brew at about 92 to 94°C, and that's a sensible place to sit. If yours lets you adjust it, run hotter for lighter single origins and cooler for milk blends.
But with espresso, temperature isn't your main lever. Shot length is. Our white coffees are roasted and blended to be pulled as a ristretto: 20g in, 15 to 20g out, 25 to 35 seconds. It's the Australian and New Zealand approach, and it's why a flat white made this way tastes sweet and dense rather than thin and bitter. Milk flattens sweetness and acidity, so the shot has to push back.
If your flat whites taste weak or bitter, shorten the shot before you touch the brew temperature. Pull The Captain short and the salted caramel arrives; pull it long and it disappears into the milk.
If you use a capsule machine, temperature and shot length are both decided for you. The coffee in the pod is the variable you control.
Troubleshooting by taste
- Sour, sharp or thin? Water too cool, or grind too coarse. Go a couple of degrees hotter.
- Bitter, dry or harsh? Water too hot, or grind too fine. Let the kettle sit a bit longer.
- Flat and dull? Often not temperature at all. Check how long ago the coffee was roasted, and whether it's been sitting ground.
Is a temperature-control kettle worth it?
If you brew pour-over regularly or like to experiment, yes. A variable-temperature gooseneck gives you control over heat and pour together. For cafetière or AeroPress, a normal kettle and a little patience are fine.
One last thing: your water
Temperature isn't the only thing about water that counts. Hard water makes coffee taste dull and chalky and scales up your machine. Very soft water can leave it tasting flat and sour. In a hard-water area, a simple filter jug can make a surprising difference, especially with lighter roasts.
Still not getting what you want from a bag? Message our roasters on BrewBuddy, our WhatsApp line, seven days a week. Tell us how you're brewing and we'll help you work out what to change.
