tags: [] - coffee/roasting - coffee/roasting/profile aliases: - Roast duration - Full roast time

Total Roast Time¶

Tags: #coffee/roasting #coffee/roasting/profile Aliases: Roast duration, Full roast time Related: Roasting MOC | Development Time Ratio | Rate of Rise | Drop Temperature | Baked Roasts Status: ✅ Complete

Overview¶

Total roast time is the elapsed time from the charge of green coffee into the drum to the drop of the roasted batch into the cooling tray. It is one of the fundamental parameters recorded in any roast profile, alongside charge temperature, turning point time and temperature, first crack time, and drop temperature. Total roast time is not simply a quality metric on its own — two roasts of the same duration can have dramatically different cup profiles depending on how energy was applied across the three main phases (drying, browning, development). However, total roast time does provide important context for assessing whether a profile is proceeding within expected parameters and for diagnosing baked or rushed roast profiles.

Typical Roast Time Ranges¶

Total roast time varies with roaster type, batch size, target roast level, and profile philosophy:

Roast context	Typical total roast time
Small-batch specialty filter (5–15 kg drum)	8–12 minutes
Commercial specialty (15–30 kg drum)	9–14 minutes
Traditional longer profiles	12–16 minutes
Fast/high-heat profiles (some specialty contexts)	7–10 minutes
Very dark commercial roasting	12–18 minutes
Sample roasting (Probat Sample, Ikawa)	5–10 minutes
Home roasting (popcorn popper, Fresh Roast)	4–8 minutes

These ranges are approximate; the appropriate total roast time for a specific roaster, batch size, and green coffee is best established through systematic profile development and cupping rather than by matching a published number.

Relationship Between Total Roast Time and Development Time Ratio¶

Total roast time and DTR interact to define the development phase duration:

Development phase time = Total roast time × (DTR / 100)

For example: - 10-minute total roast time, DTR 20% → 2 minutes development - 12-minute total roast time, DTR 18% → 2.16 minutes development

Two roasts with the same DTR but different total roast times have different development phase durations. A longer total roast time with the same DTR means more absolute time in each phase — including more time in the browning phase, which produces more Maillard reaction products.

Total Roast Time and Baking¶

Excessively long total roast times, particularly when the RoR has stalled or become flat through the browning or development phase, produce baked roast character:

Signs of baking in the profile: Flat RoR through browning; long first-crack-to-drop interval with low RoR; total roast time significantly exceeding the expected range for the roaster and batch size
Signs of baking in the cup: Flat, bread-like, lacking sweetness and brightness; distinct from underdevelopment (which is sharp and harsh rather than flat)

The risk of baking increases when a roaster attempts to achieve a light roast level by running a long, low-heat profile rather than a short, moderate-heat profile. Light roast levels are best achieved by using moderate energy and dropping at the appropriate bean probe temperature — not by extending the roast duration with reduced heat.

Total Roast Time and Rushed Profiles¶

Very short total roast times — often pursued in some high-heat specialty roasting approaches — can produce: - Insufficient drying phase, leading to under-moisture removal and steaming/flat development - Compressed browning phase, limiting Maillard reaction accumulation - An intense, brighter, more acidic cup that may be appealing for some origins but harsh for others

Whether a short profile is appropriate depends on the origin, density, and the flavour target; it is not universally better or worse than a longer profile.

Total Roast Time in Batch Consistency¶

Consistent total roast time — within ±30 seconds across batches on the same profile — is a meaningful consistency indicator: - Significant variation in total roast time at the same drop temperature indicates inconsistency in heat input, bean density, ambient conditions, or batch weight - Tracking total roast time alongside Drop Temperature and DTR provides a three-parameter check for batch consistency

Profile logging software (Artisan, Cropster) records total roast time automatically, allowing easy comparison across batches.

Key Facts¶

Total roast time = charge to drop; typical range 8–14 minutes for specialty drum roasting
Development phase duration = total roast time × DTR; same DTR at different total roast times produces different absolute development time
Long, flat-RoR total roast times → baking risk; the browning phase accumulates Maillard products without adequate driving force for final aromatic formation
Very short total roast times → rushed profiles; compressed browning and drying; potentially harsh or incomplete development
Total roast time consistency (±30 seconds) is a useful batch repeatability indicator

References¶

Changelog¶

Date	Change
2026-04-27	Note created

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