Coffee Roasting 101
Absolutely! Coffee roasting is an art and science that transforms green coffee beans into the aromatic, flavorful beans we brew. Here’s a basic overview to get you started:
Green beans: Unroasted coffee beans are referred to as “green beans” and are
smaller and denser than roasted coffee beans.
- Varietals: Coffees are typically made from two main species: Arabica (sweeter,
more complex) and Robusta (stronger, more bitter). We only use single source
FairTrade Organic coffee beans of the Arabica variety. - Origin: The region where coffee is grown influences flavor profiles. Look for
notes like fruity, nutty, or floral, depending on the origin. We choose one single
origin Fair Trade Organic coffee bean and one Organic Swiss Water Decaf
bean per season and roast it to 5 different roast levels. This ensures
predictable roasts every time
2. Roasting Process
We use a drum roaster that tumbles the beans at approx 60-80 RPM in a large drum while they are exposed to heat as air is circulated through the roaster (Insert photo of roasted here). The heat source can be provided by electric or gas burners in a drum roaster, and the air flow is controlled by a fan.
The heat is measured by two probes in the roaster, one measuring the heat of the beans (aka the bean temp = BT) and one measuring the air flowing through the roaster (aka the environmental temp = ET)
The temperature is measured by the roaster and we use computerized data logging to track the change of temperature over time to further ensure predictable consistent roasts.
- Batch Size: Is how many green beans by weight are in the batch to be roasted. We keep our roasts to the same batch size as another way to ensure consistency. The green beans are weighed and placed in the bean hopper of the roaster
- The Charge: Once the roaster is at the appropriate temperature, the beans are released into the roaster and the bean temp (BT) goes from room temperature to
- The Dry Phase:
- 1st crack
- 2nd Crack
- The Drop
- Heat Application: Roasting involves applying heat to the beans. As they heat up, they go through several stages:
- Drying Phase: Beans lose moisture and become lighter in color.
- Maillard Reaction: Sugars and amino acids react, developing flavor and color.
- First Crack: At around 385°F (196°C), beans will start to crack. This is a sign that light roasts are ready.
Second Crack: Occurs around 435°F (224°C). This indicates a medium to dark roast.
3. Roast Levels
- Light Roast: Retains original bean flavors, bright acidity.
- Medium Roast: Balanced sweetness and acidity, develops more body.
- Dark Roast: Bold, bittersweet flavors, reduced acidity, and smoky notes.
4. Cooling
- After reaching the desired roast level, cool the beans quickly to stop the roasting process. You can use a cooling tray or a colander.
5. Resting
- Let the roasted beans rest for 24 to 48 hours. This allows gases to escape and flavors to develop.
6. Brewing
- Once rested, grind the beans and brew using your preferred method (French press, pour-over, espresso, etc.).
7. Experimentation
- Keep a journal of your roasting times, temperatures, and results to refine your technique and preferences.
8. Safety Precautions
- Roast in a well-ventilated area as roasting can produce smoke. Have a fire extinguisher nearby and monitor the process closely.
Conclusion
- Coffee roasting is a rewarding journey that combines science and creativity. Enjoy experimenting with different beans and roasting profiles to discover your perfect cup!
