Foundation
6 phases, 36 chapters — from "I drink coffee" to "I can design and adjust my own recipe".
Foundation aims at one coherent mental model. Afterwards, looking at a bag that says "Ethiopia, 1,900 m, washed, light roast, citrus and jasmine", you will know what each field means, which are production facts and which are expectations rather than guarantees, and how brewing choices interact with them.
What Coffee Actually Is
See coffee as agriculture, not a packaged product.
Phase 2 · Chapter 7–12From Cherry to Green Coffee
Know what processing changes — and what a process name cannot guarantee.
Phase 3 · Chapter 13–18Roasting and Freshness
See roast as a spectrum, and understand why beans rest and why they stale.
Phase 4 · Chapter 19–24Grinding, Water, and Extraction
The conceptual center of Café OS: a causal model of extraction.
Phase 5 · Chapter 25–30Brewing Methods
Classify by method family instead of memorizing dozens of devices.
Phase 6 · Chapter 31–36Espresso, Milk, and Sensory Understanding
Understand espresso variables, describe taste in structured dimensions, and design a recipe of your own.
The 12 chapters marked MVP are the first to be written.