One of the first design decisions in RoastSource was to build around milestone-based roast logging — no connected probe required.
Why Milestones?
Most home roasters — especially Fresh Roast and popcorn popper users — don't have connected probes. You roast by sight, sound, and smell. RoastSource works with that.
During a roast, you mark key events:
| Milestone | What It Is |
|---|---|
| Charge | Beans go in — the clock starts |
| Yellowing | Green-to-yellow transition (end of drying phase) |
| First Crack | Audible popping — the most critical moment |
| Drop | Roast ends — total time and DTR calculated |
Between milestones, you can enter temperature readings every 30 seconds (the app chimes to remind you). This builds a real temperature curve from data you actually collect.
The Science Behind Profiles
When you select a bean and roast level, RoastSource generates a profile based on established roasting science:
- Rate of Rise (RoR) — targets a declining curve after first crack to avoid tipping and baking
- Development Time Ratio (DTR) — light: 15–20%, medium: 20–25%, dark: 25%+
- Charge temp — calibrated per roaster type (air roasters behave differently than drums)
Based on the work of Scott Rao, Rob Hoos, and the specialty coffee science community.
Probes Are Coming
USB and Bluetooth probe support is in active development. When probes arrive, they'll layer on top of milestones — adding continuous temperature, auto RoR, and turning point detection.
Milestones will always be the foundation. They work for every roaster, every budget, and every skill level.
Questions? Let's discuss below.