Does brewing coffee with boiling water burn it?

The myth that boiling water 'burns' coffee is one of the most persistent in the industry. To understand why it's incorrect, consider the roasting process: coffee beans are subjected to temperatures between 180°C and 230°C for several minutes to develop their flavor. If water at 100°C could burn coffee, the beans would have been incinerated long before they reached your kitchen. The chemical compounds that create the 'burnt' flavor are developed during roasting, not brewing.

That said, the temperature of your water does significantly impact extraction. Hotter water is more efficient at dissolving the soluble compounds in coffee. If you are brewing a dark roast, which is already more porous and soluble due to the roasting process, using boiling water can lead to over-extraction. This results in a cup that tastes harsh, bitter, and 'roasty'—not because it is burnt, but because you have extracted too many of the bitter tannins and heavy compounds.

For light and medium roasts, boiling water is often exactly what you need. These beans are denser and less soluble, so they require the higher energy of near-boiling water to release their delicate acids and sugars. If you use water that is too cool, you will likely end up with a sour, thin, and under-extracted cup. The 'ideal' temperature is a spectrum, not a single point, and it depends entirely on the roast level and your personal preference.

In practice, don't be afraid of the kettle. If your coffee tastes bitter, try lowering your water temperature by a few degrees or using a slightly coarser grind. If it tastes sour, try using hotter water. By viewing temperature as a tool for controlling extraction rather than a way to avoid 'burning' the beans, you gain much more control over your daily brew. Start with water just off the boil and adjust from there based on how the coffee tastes in your cup.