Overview
This set of roasts spans four different coffees and three processing styles: washed, natural, and wet hulled. The purpose was not to refine one coffee in isolation, but to observe how the Gene Café CBR-301 behaves across different coffees while holding the overall approach steady.
Across the set, the machine remained consistent. The coffees did not roast identically, but they moved through a recognisable structure. Some looked darker earlier, some felt quieter, and some gave less obvious feedback during the roast, but the system itself remained stable.
First crack was not consistently reliable across all coffees and was not treated as the primary control signal. Roast decisions remained grounded in total applied time, colour, aroma, and overall progression.
What changed most from coffee to coffee was not the behaviour of the machine, but the way each coffee expressed itself within that structure.
Core observations
- The machine continued to behave consistently across washed, natural, and wet hulled coffees
- Early roast progression remained familiar even when the coffees felt different
- First crack was not a dependable decision point across the full range
- Natural coffees continued to look darker earlier than they really were
- Wet hulled coffees appeared quieter and more restrained during roasting, but carried more weight structurally
- Total roast time and final weight loss remained the clearest hard reference points across the set
Roast data summary
| Roast | Coffee | Process | Start | In (g) | Out (g) | WL % | Start Temp °C | Target Temp °C | Target Time | TRT |
|---|---|---|---|---|---|---|---|---|---|---|
| 51 | Colombia Supremo | Washed | Cold | 250.0 | 211.2 | 15.5 | 20 | 250 | 17:00 | 13:00 |
| 52 | Colombia Supremo | Washed | Warm | 250.0 | 210.6 | 15.8 | 69 | 250 | 17:00 | 12:20 |
| 53 | Colombia Supremo | Washed | Cold | 250.0 | 211.6 | 15.4 | 21 | 250 | 17:00 | 13:00 |
| 54 | Colombia Supremo | Washed | Warm | 250.0 | 210.7 | 15.7 | 70 | 250 | 17:00 | 12:26 |
| 55 | Brazil Santos | Natural | Cold | 250.0 | 214.3 | 14.3 | 21 | 250 | 17:00 | 12:21 |
| 56 | Brazil Santos | Natural | Warm | 250.0 | 210.4 | 15.8 | 70 | 250 | 17:00 | 12:17 |
| 57 | Kenyan AA | Natural | Cold | 250.0 | 211.1 | 15.6 | 20 | 250 | 17:00 | 12:46 |
| 58 | Kenyan AA | Natural | Warm | 250.0 | 209.1 | 16.4 | 70 | 250 | 17:00 | 12:16 |
| 59 | Sumatra Wet Hulled | Wet Hulled | Cold | 250.0 | 214.8 | 14.1 | 20 | 250 | 17:00 | 12:46 |
| 60 | Sumatra Wet Hulled | Wet Hulled | Warm | 250.0 | 213.8 | 14.5 | 64 | 250 | 17:00 | 12:12 |
| 61 | Colombia Supremo | Washed | Cold | 250.0 | 212.6 | 15.0 | 22 | 250 | 17:00 | 13:01 |
| 62 | Colombia Supremo | Washed | Warm | 250.0 | 210.4 | 15.8 | 69 | 250 | 17:00 | 12:25 |
| 63 | Colombia Supremo | Washed | Cold | 250.0 | 211.0 | 15.6 | 23 | 250 | 17:00 | 13:01 |
| 64 | Colombia Supremo | Washed | Warm | 250.0 | 209.7 | 16.1 | 67 | 250 | 17:00 | 12:27 |
| 65 | Sumatra Wet Hulled | Wet Hulled | Cold | 250.0 | 213.7 | 14.5 | 21 | 250 | 17:00 | 13:31 |
| 66 | Sumatra Wet Hulled | Wet Hulled | Warm | 250.0 | 210.4 | 15.8 | 67 | 250 | 17:00 | 13:01 |
Closing note
This range of roasts feels important not because any one roast stands above the others, but because the broader pattern now feels more settled.
The machine continues to behave consistently across different coffees. What changes is the expression of the coffee, not the underlying structure of the roast.
That distinction matters. It makes the process feel less like guessing and more like learning where the coffee sits inside a system that is becoming easier to trust.