Arabica Natural, City roast

Bean colour

Roast profile

1. 0. Load

   0:00
   220°C

   You'll see: Charge beans into the heated drum

   Do: Start the timer as soon as the drum is back in.

2. 1. Drying

   0:00 - 4:15
   220°C

   You'll see: Green turns yellow, grassy smell

   Do: Let the heater run to push heat into the bean core.

3. 2. Ramp

   4:15 - 8:30
   235-240°C

   You'll see: Yellow to tan brown; smell turns bread-like and sweet

   Do: Turn the dial up to build momentum into first crack.

4. 3. First crack

   8:30 - 10:45
   225°C

   You'll see: Sharp popcorn-like snaps, beans swell, chaff flies

   Do: Note the time and drop the dial to 225°C so the roast doesn't race.

5. 4. Development

   10:45 - 11:15
   225°C

   You'll see: Cracks fade, colour evens out, sweet aroma

   Do: Hold the heat and let the colour catch up.

6. 5. Dump

   11:15
   STOP

   You'll see: City colour

   Do: Long-press Stop, pull the drum with gloves and dump into an external cooler.

Troubleshooting

Sour or grassy

Underdeveloped centre. Stretch the drying phase or give it 15-30 s more after first crack.

Flat or baked

It took too long to reach first crack (past ~11-12 min). Charge hotter to push through drying.

Uneven colour

Drop the batch to 180-200 g for better tumbling and airflow.

Burnt tips or smoky

Too much heat late in the roast. Drop the dial earlier at first crack.

• The dial reads exhaust air, not bean temperature - roast by time, sound and colour.
• First crack is hard to hear over the fan: watch for beans swelling and chaff pouring into the collector.
• Keep preheats brief and under 200°C to protect the drum seals.
• Roast by an open window or under a hood, and never leave the machine running unattended.

Roasting a different coffee?