## TL;DR

Coffee originated in Ethiopia (legend of Kaldi, goats dancing after eating coffee cherries). Spread: Yemen (15th century, first cultivation) → Ottoman Empire → Europe (17th century, coffeehouses: 'penny universities') → Americas (18th+). Species: Arabica (~60%, better flavor) vs. Robusta (hardier, more caffeine). Second most traded commodity after oil.

## Core Explanation

Processing: washed (clean, bright), natural (fruity, fermented), honey (between). Roast: light (origin flavors), medium (balance), dark (roast flavors). Brew methods: espresso (pressure), pour-over (gravity), French press (immersion), cold brew (time). Third Wave Coffee (2000s): treat coffee as artisanal product — single origin, direct trade, lighter roasts. Caffeine: most consumed psychoactive substance — blocks adenosine (sleep signal).

## Further Reading

- [The World Atlas of Coffee (James Hoffmann, 2nd Ed)](https://www.octopusbooks.co.uk/titles/james-hoffmann/the-world-atlas-of-coffee/9781784725716/)