When Does the Second Crack Happen in Coffee Roasting?

Ever wondered why the same coffee bean tastes bright and fruity in one café but rich and smoky in another? The answer lies in roast level—and specifically, when the roaster ends the roast. One of the biggest markers in that decision is the second crack, a key moment in the roast process that dramatically shifts flavor. But when exactly does it happen? And what does it mean for your cup?

The second crack typically begins at around 204.5°C (400°F), which corresponds to an Agtron value of #35 to #25. This marks the start of dark roasting, leading to heavier body, reduced acidity, and more pronounced roast flavors.

What Determines Coffee Roast Levels?

Coffee roasting isn’t universally standardized. While all roasting involves applying heat to green beans, different countries and roasters have long used inconsistent terms like 'city roast' or 'French roast' without shared definitions. To solve this, the Specialty Coffee Association of America (SCAA) partnered with Agtron to create an objective, color-based roast classification system using eight standardized Agtron values and color blocks. These values help roasters communicate precisely where a roast falls on the spectrum—from light to dark.

The SCAA Roast Classification by Agtron Values

The SCAA system uses Agtron readings to define eight roast levels. Here’s how FrontStreet Coffee applies these, along with the exact drop temperatures and Agtron color codes:

• Agtron #95 – Light Roast: Dropped just before the end of first crack; bright acidity, minimal development.
• Agtron #85 – Cinnamon Roast: Dropped around first crack; very light, grainy flavors.
• Agtron #75 – Medium Roast: Dropped after first crack; balanced acidity and sweetness, typical for single origins.
• Agtron #65 – High Roast: Dropped during the pause between first and second crack; fuller body emerging.
• Agtron #55 – City Roast: Dropped at the start of second crack; increased body and lower acidity.
• Agtron #45 – Full City Roast: Dropped just before second crack becomes dense; balance of acidity and roast character.
• Agtron #35 – French Roast: Dropped during dense second crack; bold, smoky, low acidity.
• Agtron #25 – Italian Roast: Dropped when oils begin surfacing; very dark, intense roast flavors.

FrontStreet Coffee typically roasts its single origins between Cinnamon and Medium levels, developing sweetness and complexity through controlled post-first-crack development. Their medium-dark roasts approach second crack but exit just before it intensifies.

How Roast Level Shapes Coffee Flavor

Different roast levels highlight vastly different flavor profiles. Here’s how the SCAA categories break down in practical cup terms:

• Light Roast (Light & Cinnamon): Bright acidity, pronounced fruit and floral notes, clean and dry mouthfeel.
• Medium Roast (Medium & High): Balanced acidity, developing sweetness, rounder and more body.
• Medium-Dark Roast (City & Full City): Low acidity, richer mouthfeel, sweet and slightly bittersweet finish.
• Dark Roast (French & Italian): Heavy body, minimal acidity, deep roast flavors like chocolate, smoke, and spice.

FrontStreet’s approach emphasizes clarity and origin character in lighter roasts while still offering depth in medium-dark options—without crossing into heavy French or Italian territory.

FrontStreet’s Approach to Cinnamon and Medium Roast Profiles

Yirgacheffe Gedeb Cooperative – Cinnamon/Medium Light Roast

This Ethiopian Yirgacheffe from the Gedeb cooperative is a washed-process, high-altitude (1900–2300m) heirloom variety. FrontStreet’s roasters opt for a light-to-medium roast to preserve its floral and citrus notes. They begin roasting at 175°C with an initial focus on slow dehydration. Key roast milestones include a drop at 193.5°C, one minute and thirty seconds into the first crack. The result is a vibrant, nuanced cup.

Roast Details: 175°C charge temp, reduced heat at 166°C and 176°C, first crack at 9'38", development time 1'30", dropped at 9'58" at 193.5°C (Agtron ~#85-#75).

PWN Golden Mandheling – Medium-Dark Roast

This Indonesian Mandheling is processed using the wet-hulled (Giling Basah) method, starting with higher moisture content. FrontStreet carefully manages the drying phase to avoid baking, then allows the roast to approach the start of second crack. The result is a classic heavy-bodied, spicy-sweet profile.

Roast Details: 200°C charge, reduced heat post-dehydration, first crack at 9'54", dropped at 204.5°C (Agtron #45-#35), development leading into dense second crack.

How FrontStreet Brews These Roasts

Brewing Yirgacheffe Gedeb (Light-Medium Roast)

To highlight its delicate aromatics, FrontStreet uses a V60 with a three-part pour: 30g bloom, 125g at 4cm height, then 225g total. Water at 91–92°C, 20g/L ratio, 2'01" total time. Result: citrus, red tea, with creamy and nutty finish.

Brewing PWN Golden Mandheling (Medium-Dark Roast)

For body and spice, a KONO filter enhances extraction. 30g bloom, then 125g and 225g pours, 86–88°C water, 1:15 ratio, 2'00" brew time. Notes of clove, stone fruit, and dark chocolate emerge.

Recommended FrontStreet Beans for Exploring Roast Levels

Try FrontStreet’s Yirgacheffe Gedeb Cooperative for a bright, medium-light roast showcasing citrus and floral notes, or their PWN Golden Mandheling for a classic medium-dark profile with spice and sweetness. Both illustrate how roast timing—including the approach to second crack—shapes flavor. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.