Coffee: Brewing Temperature — SCA Standards and Extraction Effects

Water temperature is one of the most controllable variables in coffee brewing and has a direct, well-documented effect on extraction yield and flavor balance. The Specialty Coffee Association (SCA) specifies a brewing water temperature of 93°C ±2°C (200°F ±3°F), representing decades of empirical refinement.

Why Temperature Matters

Temperature governs the solubility and extraction rate of coffee’s chemical compounds. Coffee contains hundreds of soluble compounds, and they do not all dissolve at the same rate or respond to temperature identically:

• Acids (chlorogenic, citric, malic): Extract relatively quickly even at lower temperatures, and some thermolabile acids degrade at high temperatures.
• Sugars and Maillard compounds: Require adequate temperature to dissolve efficiently; contribute sweetness and body.
• Bitter phenolics and chlorogenic acid degradation products: Increasingly soluble at higher temperatures; extraction accelerates above ~93°C.
• Lipids and aromatic volatiles: Temperature-sensitive; higher temperatures can drive off desirable aromatics during brewing.

Extraction Zones

Temperature Range	Extraction Character	Dominant Flavors
4°C (cold brew)	Extremely slow, 12–24h steep	Low acidity, chocolate, mellow bitterness
Below 87°C	Under-extracted	Sour, grassy, thin, sharp acidity, weak body
87–91°C	Slightly under	Bright, acidic, lighter body, acceptable
91–95°C (SCA target)	Optimal extraction	Balanced acid, sweetness, body, complexity
95–96°C	Slightly over	Increased bitterness, fuller body
Above 96°C	Over-extracted	Harsh, astringent, bitter, flat
100°C (boiling)	Severe over-extraction	Rubbery, bitter, scorched notes

Method-Specific Temperature Guidance

Different brewing methods require slight adjustments within the SCA’s acceptable range:

Pour-over (V60, Chemex, Kalita): Many specialty baristas brew at 94–96°C to compensate for temperature loss during the pour. Each pour drops brew water temperature approximately 2–3°C as it contacts coffee grounds and the vessel.

French press: A full-immersion method that retains heat better. 93°C is appropriate. Longer steep times (4 minutes) mean temperature drop is more significant — insulated vessels help.

AeroPress: Versatile; lower temperatures (80–85°C) can produce interesting results with light roasts, exploiting selective acid extraction. Not under-extraction when intentional and balanced.

Espresso: The boiler or heat exchanger is set higher than the actual brew temperature at the puck. A boiler set to 93°C might deliver water at 88–92°C at the group head, depending on machine design. E61 group heads thermally regulate but require careful flush protocols. Modern PID-controlled machines aim for 90–95°C at puck.

Cold brew: Room temperature (20–22°C) or refrigerator temperature (4°C). 12–24 hour steeping time. The resulting concentrate has a distinct chemical profile — lower total acid, different bitter compound ratios, less aromatic complexity than hot brewed.

Roast Level and Temperature Interaction

Dark roasts have more porous, friable cell structure due to CO₂ degassing during roasting. They extract faster and at lower temperatures than light roasts. Brewing a dark roast at 96°C risks over-extraction and harsh bitterness. Light roasts, conversely, have denser cellular structure — slightly higher temperatures (94–96°C) help achieve adequate extraction.

Roast Level	Recommended Temperature
Light / Nordic	94–96°C
Medium	92–94°C
Medium-Dark	91–93°C
Dark	88–91°C

Measuring Brew Temperature

Consumer-grade electric kettles with temperature control (e.g., Fellow Stagg, Bonavita variable) hold accuracy to ±1°C. An off-boil approach (boil, wait 30 seconds) yields approximately 94–96°C at sea level — note that at altitude, water boils at lower temperatures (at 2,000m, boiling point is ~93°C, meaning “boiling” water is already in the SCA target range without waiting).

Accurate temperature measurement requires a probe thermometer inserted at the outlet of the kettle or at the point of contact with grounds — not the water reservoir temperature alone.