Coffee Roasting Timer Calculator
Created by: Emma Collins
Last updated:
Track roast phase structure and development ratio from key roast events.
Coffee Roasting Timer Calculator
CoffeeCalculate roast phase durations and development ratio
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What is a Coffee Roasting Timer Calculator?
Turning roast events into usable metrics
A coffee roasting timer calculator organizes critical roast milestones into repeatable phase metrics. It helps you standardize drying, Maillard, and development timing across batches.
Consistent timing logs improve profile repeatability and speed up roast troubleshooting when flavor drifts from target.
Structured timing references also improve communication between operators, especially during shift changes. That makes profile corrections faster and more objective.
Core Timing Formulas
Phase breakdown framework
Drying = Dry-End Time Maillard = First Crack Time − Dry-End Time Development = Drop Time − First Crack Time DTR (%) = Development ÷ Drop Time × 100
These values create a quick quality-control framework for comparing roasts by structure, not just total duration.
With clear phase metrics, teams can diagnose whether differences came from early drying, mid-roast browning, or final development choices.
Example
Phase timing interpretation
If drying ends at 4:30, first crack starts at 8:40, and drop occurs at 10:50, development is 2:10 and DTR is about 20%. This typically aligns with a medium roast profile target.
If DTR rises while total time also stretches, cup results may trend flatter. Use this context to fine-tune heat taper and end-of-roast pacing.
Applications
Daily production use
Use this tool for roast logging, production consistency checks, and profile transfer between different batch sizes.
It is also useful for onboarding staff because event definitions become explicit and easy to audit in shared logs.
Tips
Improve event-marking accuracy
Assign one person to call and record critical events during training runs. Consistent timing discipline reduces noise in profile comparisons.
Mark events in real time during roasting and avoid backfilling from memory.
Track both timing and end temperature for tighter repeatability.
Frequently Asked Questions
What should I track with a roasting timer?
A practical timer should track drying end, first crack, development start, and drop time. These checkpoints help compare batches and make repeatable roast adjustments.
Why is first-crack timing important?
First crack marks a key transition from browning toward development. Keeping this event in your log helps control cup balance and avoid baked or underdeveloped outcomes.
Can this replace a temperature probe?
No. Time markers and bean temperature work best together. Use this timer as a planning and consistency tool, then validate decisions with sensory and temperature data.
What is a good development target?
Many filter roasts land around 18–22% development time ratio and many espresso roasts around 20–25%, but ideal values depend on bean density, process, and flavor goals.
Sources and References
- Rao, Scott. The Coffee Roaster’s Companion. Roast event timing and development management principles.
- SCA Roasting Foundations references for roast stage terminology and process control.