tags: [] - coffee/roasting - coffee/roasting/roast-level aliases: - Dark roasted coffee - Dark roast level - Full roast

Dark Roast¶

Overview¶

Dark roast is a roast level characterised by bean temperatures at drop typically above 220 °C, significant oil migration to the bean surface, and a cup profile dominated by roasty, bitter, and smoky notes rather than the origin characteristics — varietal, processing, and terroir qualities — that lighter roast levels preserve. Dark roasts have been the commercial standard in European espresso traditions, particularly Italian, and in mass-market filter coffee globally for much of the 20^th century; they remain commercially dominant by volume, though specialty coffee culture has largely moved toward lighter roast levels that emphasise origin-driven flavour. Within the broad category of dark roast sit several named levels including Full City+, Vienna, French, and Italian.

Defining Dark Roast¶

There is no single universally agreed boundary between medium and dark roast. In practice, dark roast is defined by a combination of:

Drop temperature: Typically above 215–220 °C for a drum roaster, though the exact figure varies by roaster equipment
Colour: Agtron roast colour scores below approximately 45 (on the Gourmet scale) or 35 (on the Commercial scale); the SCA uses the Agtron scale as its standard colour reference
Bean surface: Oil visible on the bean surface; dark roasts beyond French or Italian show pronounced oiliness
Development Time Ratio: Extended development phases, often 22–30%+ of total roast time
Weight loss: Greater than approximately 15–16% of the green weight, compared to 12–14% for medium

Named Dark Roast Levels¶

Name	Approximate Agtron (Gourmet)	Character
Full City+	45–50	Second crack beginning; oil just emerging; bittersweet chocolate; origin notes fading
Vienna	35–45	Second crack; oily surface; roasty, caramel bitterness; minimal origin character
French	25–35	Heavy oil; dark chocolate, ashy, smoky; acidity suppressed; strong bitterness
Italian	Below 25	Very dark; intensely bitter, smoky, tar-like; origin entirely masked

These names are not standardised — different roasters and markets use them inconsistently. The SCA Roast Color Classification system, using Agtron scores on whole-bean and ground samples, provides a more objective reference.

Cup Profile¶

Dark roasted coffees share common sensory characteristics regardless of origin:

Aroma: Roasty, smoky, dark chocolate, carbon; origin aromatics largely absent
Acidity: Suppressed; chlorogenic acids and other acidic compounds degrade at high temperatures; the cup reads as flat or low-acid
Body: Initially full; at extreme dark levels (French/Italian), perceived body can thin due to cellular structure breakdown
Flavour: Bittersweet chocolate, caramel, toast, smoke, carbon; varietal and terroir notes absent
Aftertaste: Persistent bitterness; roasty dryness

The suppression of acidity in dark roasts is chemical: acids formed during the Maillard and caramelisation stages degrade under sustained high heat, and some roasters specifically use dark roasting to reduce perceived sourness in lower-quality green coffees.

Dark Roast and Espresso¶

The conventional Italian espresso tradition is built around dark-roasted blends, typically Vienna to French level. Dark roasting reduces acidity and creates soluble compounds that form crema readily under espresso pressure. However, the specialty espresso movement from the 2000s onward has demonstrated that lighter roast levels (often called "Nordic" or "third wave" espresso) can produce intensely flavourful, complex espresso when grind, pressure, and water temperature are calibrated appropriately — a development that has significantly shifted the specialty industry's approach to espresso roasting.

Caffeine in Dark Roast¶

A common misconception holds that dark roasts are stronger or higher in caffeine than light roasts. In practice, the difference in caffeine content between roast levels is negligible by weight, as caffeine is relatively heat-stable and does not degrade significantly within the roasting temperature range. However, because dark roasting causes greater weight loss (the bean loses more water and organic material), a gram of dark-roasted coffee contains slightly more caffeine by weight than a gram of light-roasted coffee — but the difference is practically insignificant for normal dosing.

Key Facts¶

Defined by drop temperatures above ~215–220 °C; Agtron score below ~45 (Gourmet scale)
Named levels: Full City+, Vienna, French, Italian — from lightest to darkest dark
Cup profile: roasty, bitter, smoky; origin characteristics suppressed or absent
Oil migration to bean surface occurs as cellular structure breaks down at high development temperatures
Commercial coffee globally has historically used dark roast; specialty movement favours lighter levels
Caffeine content does not significantly decrease with darker roasting

References¶

Changelog¶

Date	Change
2026-04-27	Note created

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