Coffee brewing is a chemical extraction process. Water acts as a solvent that extracts soluble compounds–acids, sugars, and oils– from the coffee beans. These compounds make up the coffee’s distinct flavors. The temperature of the water directly influences the rate and amount of soluble compounds extracted. But what is the ideal brewing temperature, and what happens if the water is too hot or cold?

The Best Brewing Temperature

The National Coffee Association states that the ideal brewing temperature of coffee is between 195°F and 205°F (90°C to 96°C). When the water is between these temperatures, it can efficiently extract the desirable, flavorful compounds from the ground coffee beans. Properly extracted coffee will have a balanced sweetness that complements its acidity and bitterness, allowing you to taste and smell the full depth of its flavors and aromas.

Over-Extraction (Water Temperature Above 205°F / 96°C):

When the water is too hot, it extracts too many soluble compounds from the coffee grounds. Higher temperatures extract acids quickly; as a result, the over-extracted coffee can taste overly bitter, astringent, and harsh. These unpleasant, bitter compounds may overshadow delicate flavors, such as fruity or floral notes. There are pleasant bitter coffee notes like cocoa, grapefruit, or dark chocolate; however, over-extraction kills all the subtleties in a coffee’s overall flavor.

Under-Extraction (Water Temperature Below 195°F / 90°C):

When the water is too cool, it fails to extract enough soluble compounds, making the coffee taste weak, sour, or overly acidic. When the water isn’t hot enough, the extraction process doesn’t fully develop and release the sugars and oils from the coffee beans that balance out the acidity. Lower temperatures extract acids slowly, which creates an under-extracted coffee that lacks depth and complexity.

When you understand how water temperature affects extraction and the flavor of your coffee, you can take control of the brewing process and create a cup that’s perfectly suited to your palate.