Overview
Interview with coffee roasting consultant and author Rob Hoos about his new book on roasting for different coffee cultivars. Discussion covers grouping cultivars, practical roasting guidance, sample vs production roasting, market realities, and improving quality across roast levels.
Sponsor Mention: Mill City Roasters
- Sponsor highlighted for education, attentive tech support, and classes.
- Host attended Roaster 101; recommends checking class schedules and calling for guidance.
About Rob Hoos and the New Book
- Third appearance; prior work: Modulating the Flavor Profile of Coffee, tipping avoidance.
- New book focuses on cultivars and roasting approaches by cultivar group.
- Research launched summer 2023; systematic experiments plus live group Zoom tastings.
- Rob offers consulting, courses, and books at host.coffee.
Why Study Cultivars Systematically
- Moves beyond anecdote to test common lore and its real-world applicability.
- Example: Maragogipe roasted faster (7–7.5 min to first crack, short development) yields bright, tropical complexity vs historically slow, savory results.
- Goal: help roasters land within 2–3 roasts, not 5–10, during product development.
Grouping Cultivars and Practical Use
- Groups show similar tendencies: Typica-oriented, Bourbon-oriented, Catimor/Timor-hybrid types, Ethiopian landrace (in Ethiopia or abroad).
- Not perfect, but a strong starting framework when exact cultivar guidance is absent.
- Intended to guide purchase decisions and roast development tailored to menu needs.
Key Roasting Principles by Cultivar Tendencies
- Faster isn’t always better; some groups benefit from longer time to first crack while staying light.
- Ethiopian landrace group: earlier first crack (~7.5 min) often best; 9-minute first crack risks savoriness.
- Maragogipe behaves closer to Typica; thrives with faster profiles and short development despite large bean size.
- Bourbon-oriented cultivars tolerate longer time-to-first-crack without turning savory as quickly.
Sample vs Production Roasting
- Core principle: flavor depends on heat transfer over time; one bean or a million, match chemical reactions, color, and weight loss.
- Fluidized-bed sample roasters differ greatly from drum roasters (much higher airflow per gram).
- Small batch vs full batch on drum: less difference than many assume if reaction timelines are matched.
Omni-Roast, Workflow, and Practicality
- Omni-roast demands high barista skill; can yield thin/misaligned espresso, especially with milk.
- Light-roast guidance in the book targets filter coffee; espresso often benefits from slightly longer to first crack for milk balance.
- Large roasters still handle small volumes of exotic lots; smaller roasters need precise development due to limited blending buffers.
Flavor, Cultivar, and Terroir Perspectives
- Cultivar flavor signatures can persist across origins (e.g., Castillo in PNG vs Colombia).
- Historic “terroir” descriptors often reflected processing norms and cultivar availability.
- Cultivar choice affects product placement: lower-acidity cultivars (e.g., Caturra, Bourbon) may suit dark roasts better than high-acid types (e.g., SLs, Pacamara, Castillo).
Practical Profiling Guidance
- Rob works in time, not development percentage; provides development time ranges and suggested first crack timings by group.
- Places emphasis on timing to yellowing and its proportion of total time-to-first-crack.
- Cautions against racing to yellow and then stretching to first crack, which can unbalance pressure and flavor outcomes.
Market Realities and Customer Focus
- Expensive, exotic coffees often need active promotion; “employee retention coffees” excite teams but may move slowly.
- More expensive coffees are harder to ruin; cheaper coffees have smaller sweet spots and require greater precision.
- Dark-roast customers are highly loyal and sensitive to deviations; dark roasting deserves care and attention.
- Elevating quality across light, medium, and dark roasts serves community preferences and strengthens brands.
Action Items
- Map current menu coffees to cultivar groups to choose appropriate starting profiles.
- Adjust sample roast protocols by cultivar group, especially time to first crack and yellowing placement.
- Reassess omni-roast strategy; consider tailored espresso profiles for milk-heavy service.
- Use cultivar tendencies to inform purchasing for specific product lines (e.g., dark roast suitability).
- Test faster vs slower profiles within each group to locate the local “window” before savoriness/paperiness.
- Document time-based targets, color, and weight loss to replicate across batch sizes.
Decisions
- The book provides starting profiles and time targets by cultivar group to shorten development cycles.
- Emphasis on light-roast filter guidance now; ongoing experiments extend to dark roasts and espresso.