Coffee Roasting Week 2: Moisture and Water Activity in Green Coffee

This is week two of my coffee roasting study plan. Lesson one covers moisture content and water activity in green coffee: what the two numbers mean, how they change the way a bean takes heat in the roaster, and how they affect storage. I go through the working range for moisture, the water activity thresholds, and how to read the two numbers together. I also cover how drying at the origin affects both, and what to record in a green coffee log before every roast. After the lesson I read through the week's coffee news: a new industrial brewing system, women coffee and cacao farmers, coffee tourism in Vietnam, Panama Canal shipping capacity, and a Guatemalan farmer soil study. Chat wasn't working at the start of the stream, so the first minute or so is me sorting that out. Chapters 0:00 Going live and fixing chat 1:10 Week 2 setup 2:00 Prerequisites and lab materials 3:46 Moisture content 5:13 Why moisture matters in the roast 6:34 Measuring moisture 7:49 Water activity and storage 9:54 How drying at origin affects both 12:50 Reading moisture and water activity together 14:17 The green coffee log 15:51 Key takeaways 16:55 Coffee news 20:23 Guatemala farmers and soil science