[FrontStreet Coffee Roaster's Notes] Different Flavor Expressions of Costa Rica Black Soul at Various First Crack Times

Understanding the "First Crack" in Coffee Roasting

Today, I'd like to discuss the timing of the "first crack" in coffee roasting. What exactly is the "first crack"? As coffee beans go through the dehydration phase, water and other substances produce carbon dioxide when heated. This causes the coffee beans to continuously expand, eventually breaking through the cell walls and creating a distinctive cracking sound.

For this demonstration, I'll be using FrontStreet Coffee's Costa Rica Alma Negra to compare different roasting profiles.

Finca Las Lajas Alma Negra

Costa Rica · Alma Negra

Coffee Details:

Name: FrontStreet Coffee Costa Rica Natural Alma Negra

Country: Costa Rica

Region: Central Valley

Altitude: 1300-1500m

Processing: Natural Process

Grade: SHB

Variety: Caturra, Catuai

Green Bean Analysis

The green beans of FrontStreet Coffee's Costa Rica Natural Alma Negra display the typical yellow-green color of natural processed coffee, with a subtle hawthorn-like acidity in aroma. The beans feel relatively hard and have a higher moisture content.

Roasting Profile Comparison

FrontStreet Coffee Costa Rica Alma Negra Roasting Profile #1

FrontStreet Coffee uses a Yangjia 800N semi-direct flame roaster (300g batch size).

Preheat the roaster to 170°C before loading the beans, with the damper set at 3. After 30 seconds, increase the heat to 90. The turning point occurs at 1'38" at 107.2°C. At 140°C, maintain the heat level and open the damper to 4. At 166°C, reduce heat to 80, and at 176°C, further reduce to 50. At 4'40", the beans turn yellow as the grassy aroma disappears, entering the dehydration phase. Maintain heat and keep damper at 4.

At 7'17", dehydration completes as wrinkles and dark spots appear on the bean surface, with the aroma shifting from toast to coffee—this signals the approaching first crack. Pay close attention for the first crack sound. At 7'30", first crack begins. Open the damper fully to 5 while maintaining heat. At 187°C, reduce heat to 30. The development time after first crack is 1'45", with beans dropped at 193°C.

FrontStreet Coffee Costa Rica Alma Negra Roasting Profile #2

Preheat the roaster to 170°C before loading the beans, with the damper set at 3. After 30 seconds, increase the heat to 90. The turning point occurs at 1'36" at 108.8°C. At 140°C, maintain the heat level and open the damper to 4. At 166°C, reduce heat to 60. At 4'45", the beans turn yellow as the grassy aroma disappears, entering the dehydration phase. Maintain heat and keep damper at 4.

At 7'58", dehydration completes as wrinkles and dark spots appear on the bean surface, with the aroma shifting from toast to coffee—this signals the approaching first crack. Pay close attention for the first crack sound. At 8'11", first crack begins. Open the damper fully to 5 while adjusting heat to 40. The development time after first crack is 1'45", with beans dropped at 194°C.

FrontStreet Coffee Costa Rica Alma Negra Roasting Profile #3

Preheat the roaster to 170°C before loading the beans, with the damper set at 3. After 30 seconds, increase the heat to 90. The turning point occurs at 1'36" at 109.9°C. At 140°C, maintain the heat level and open the damper to 4. At 166°C, reduce heat to 60, and at 176°C, further reduce to 40. At 4'45", the beans turn yellow as the grassy aroma disappears, entering the dehydration phase. Maintain heat and keep damper at 4.

At 8'14", dehydration completes as wrinkles and dark spots appear on the bean surface, with the aroma shifting from toast to coffee—this signals the approaching first crack. Pay close attention for the first crack sound. At 8'30", first crack begins. Open the damper fully to 5 while maintaining heat. The development time after first crack is 1'45", with beans dropped at 192.5°C.

Cupping Comparison

Alma Negra Roasting Profile #1

FrontStreet Coffee cupping notes: Floral, citrus, fermented, grapefruit, toast, melon, cream

Alma Negra Roasting Profile #2

FrontStreet Coffee cupping notes: Floral, orange, fermented, maple, nuts, oolong tea, cocoa, passion fruit

Alma Negra Roasting Profile #3

FrontStreet Coffee cupping notes: Floral, orange, almond, black tea, woody, leather

(Numbers 1-3 indicate ranking)

Clever Brewer Comparison

FrontStreet Coffee brewing parameters: 90°C/1:15 ratio/15g coffee/227g water/grind size BG-5R

Alma Negra Roasting Profile #1

Method: Pour water to 227g, steep for 4 minutes, then begin filtering. Remove the brewer once the coffee bed is visible. Total time: 4'31"

Flavor profile: Nuts, caramel, orange, genmaicha, woody, grapefruit, berries, honey

Alma Negra Roasting Profile #2

Method: Pour water to 227g, steep for 4 minutes, then begin filtering. Remove the brewer once the coffee bed is visible. Total time: 4'30"

Flavor profile: Brown sugar, raspberry, floral, woody, honey, chocolate, prominent sweetness

Alma Negra Roasting Profile #3

Method: Pour water to 227g, steep for 4 minutes, then begin filtering. Remove the brewer once the coffee bed is visible. Total time: 4'37"

Flavor profile: Tea-like, fermented aroma, genmaicha, brown sugar, maple, leather

Analysis and Conclusion

Through these three roasting profiles of FrontStreet Coffee's Costa Rica Alma Negra, with consistent development time after first crack and similar dropping temperatures, FrontStreet Coffee's roasters adjusted the timing of the first crack—commonly known as the "dehydration period." During this time, the Maillard reaction primarily occurs.

For Profile #1, the first crack occurs at 7'30", with rapid temperature increase during roasting and consistently high heat levels. The resulting coffee beans show more wrinkles and appear less plump with somewhat uneven coloration, reflecting insufficient Maillard reaction time in some beans. In cupping and Clever Brewer brewing, the flavors lean toward fruit acidity with some woody off-notes and a slightly thinner mouthfeel. This likely results from the early first crack timing, where beans haven't absorbed sufficient heat to expand properly before entering the first crack stage, leaving some off-notes insufficiently decomposed.

For Profile #2, the first crack occurs at 8'11", with a slightly slower temperature increase than Profile #1. The beans appear plumper with more uniform coloration, reflecting consistent Maillard reaction across all beans. In cupping and Clever Brewer brewing, the flavors show more complexity with prominent sweetness and minimal off-notes.

For Profile #3, the first crack occurs at 8'30", with the slowest temperature increase among the three profiles. The beans from this profile are very plump due to the extended time before first crack, allowing for proper expansion. The bean color is also quite uniform. In cupping and Clever Brewer brewing, the flavors are more balanced with a slightly fuller body but less complexity, leaning more toward nutty, caramel, and tea-like notes, while fruit and floral characteristics are relatively weaker. This profile produces coffee with more singular flavor characteristics because the longer time before first crack causes some sugars to convert to caramel while a larger portion decomposes, resulting in more balanced brewed flavors.

After comparing all three roasting profiles, FrontStreet Coffee's roasters concluded that Profile #2 offers the best flavor and complexity. This also demonstrates that the timing of the first crack significantly impacts flavor and mouthfeel. Shorter timing tends to produce off-notes and thinner mouthfeel, while longer timing may cause some desirable flavors to decompose, resulting in a fuller body but more singular flavor profile. Therefore, controlling the timing of the first crack is a crucial aspect of coffee roasting.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473