If you want to go deeper on the science and craft of coffee roasting, here are the resources that have been most useful to me and to the roasters I've talked to. This isn't an exhaustive list — it's the ones actually worth your time.
I love to read and learn - so always looking for new things to read and keeping track of the different forums for the latest developments (or anything I should consider for the RoastSource software)
Books
The Coffee Roaster's Companion by Scott Rao — The standard reference for roast science. Covers heat transfer, RoR, development, defects, and profiling in clear, practical language. Not cheap, but if you only buy one book, this is it.
Modulating the Flavor Profile of Coffee by Rob Hoos — Shorter and more focused than Rao. Excellent on how roast decisions (charge temp, airflow, heat application) map to specific flavor outcomes. Very practical for home roasters.
The World Atlas of Coffee by James Hoffmann — Not a roasting book, but essential for understanding origins, processing, and what makes Ethiopian coffee taste different from Guatemalan. Updated edition covers newer origins and processing methods.
Coffee: Growing, Processing, Sustainable Production (Wintgens) — The academic reference. Dense, expensive, comprehensive. Good for understanding the agricultural side — variety, terroir, post-harvest processing. Not a casual read.
Online Resources
Sweet Maria's Library (sweetmarias.com/library) — Free, extensive, practical. Their roasting guides, origin descriptions, and cupping tutorials are where many home roasters learned the basics. Updated regularly.
James Hoffmann's YouTube channel — Consistently excellent content on brewing, tasting, and coffee science. His roasting content is more limited (he's more of a brewer/taster) but everything he covers is well-researched.
SCA (Specialty Coffee Association) — Offers formal courses and certifications in roasting, sensory skills, and green coffee. Expensive but thorough. The Introduction to Coffee and Sensory Skills Foundation courses are good starting points if you want structured learning.
Mill City Roasters YouTube — Focused on commercial roasting but the principles translate directly to home roasting. Their roast analysis videos are some of the best free content on understanding profiles.
What I'd Recommend Starting With
If you're new: Sweet Maria's library + Hoffmann's YouTube. Free, practical, well-explained.
If you're intermediate and want to understand the science: Rao's The Coffee Roaster's Companion. Worth every penny.
If you're interested in origins and sourcing: Hoffmann's World Atlas of Coffee.
What resources have helped you the most? Any books, courses, or channels I should add to this list?