A short course, with the dials attached
Everything that happens between a seed and a cup.
Start with the reference — what coffee is, botanically, and where every name on a bag comes from. Then three chapters, each built around one instrument you can actually drag: what a coffee is capable of tasting like before you touch it, the two ways you can still ruin it, and how to say what ended up in the cup.
Nothing here needs installing, an account, or a network. Every page is a single static document and every model runs in front of you, so the fastest way to learn any of it is to break it on purpose.
Species and varieties
Three species are farmed; almost everything you drink is two of them. Every other name on a bag — Bourbon, Gesha, Caturra, Castillo — is a variety of one species. The whole tree, with what each branch tastes like.
Open the reference → Chapter 1Flavour is decided before you grind
Species, origin, elevation, process and roast. Four decisions fix most of what a coffee can taste like — and the last one quietly erases the other three.
Open the flavour builder → Chapter 2Dial in your cup
Sour and bitter are opposite failures, and most people fix them in exactly the wrong direction. An extraction simulator with immersion and percolation modes.
Open the extraction simulator → Chapter 3Naming what you taste
An interactive cupping sheet — the vocabulary for describing a cup precisely enough that someone else can act on it.
Open the cupping sheet →How to read it
In order, if you have the time. The three chapters answer different parts of the same question, and they answer it in the order the coffee actually travels: the bean decides what is possible, the brew decides how much of it you get, and your palate decides what you can say about it. Each one ends with a link to the next.
The models are teaching models. The relationships in them are real and worth trusting; the third decimal place is decoration, and each panel says so in its own footer.