The Honest Coffee Handbook

Most advice about home coffee starts with equipment, which is convenient for everyone selling equipment. This handbook starts somewhere less flattering: with the fact that a €900 espresso machine will not save a cup that was ground wrong.

Every bad cup fails in one of two directions

Coffee brewing has exactly one thing going on — water dissolving compounds out of ground coffee — and every fault is a matter of doing too much or too little of it.

Bitter, dry, ashy, coating your tongue? The water worked too long or too hard. Having taken everything good, it kept going and started pulling out the harsh, papery compounds that sit deeper in the grounds. That’s over-extraction.

Sour, thin, salty, oddly grassy? The water left too much behind. It grabbed the fast-dissolving acids and ran before it collected the sugars and heavier compounds that balance them. That’s under-extraction.

Grind size, water temperature, brew time, ratio, technique — every one of them is just a lever pushing extraction one way or the other. Once that clicks, coffee stops being a pile of superstitions (“always pour clockwise”) and becomes a system you can debug.

The order of what matters is not the order things are sold in

If you upgrade one thing, upgrade the grinder — not the kettle, not the brewer, not the beans.

A blade grinder produces boulders and dust at the same time. The dust over-extracts and turns bitter; the boulders under-extract and turn sour; the cup manages to fail in both directions at once. No technique fixes this, because there is no single correct brew time for particles that different. A burr grinder crushes beans between two surfaces a fixed distance apart and gives you particles of roughly one size. That is the difference between coffee you can control and coffee you can only endure.

Water comes next, and almost nobody talks about it despite it being 98.5% of the drink. Too soft — distilled, heavily filtered — and the cup goes flat and hollow, because minerals like magnesium are what actually bind to flavour compounds and carry them over. Too hard, which covers much of continental Europe, and high alkalinity buffers away exactly the bright notes that make good coffee worth buying.

Strength and balance are different dials

The most common mistake in home brewing is treating them as one. Ratio controls strength: how concentrated the cup feels. Extraction controls balance: where it sits between sour and bitter.

They move independently, which is why weak-and-over-extracted is so common — too little coffee, ground too fine, steeped too long. People taste the thinness, use even less water next time, and spiral. Adjust ratio for strength. Adjust grind for balance. Keeping those two jobs separate is the single most clarifying habit available to a home brewer.

Start at 1:16 for pour-over (15 g coffee, 240 g water), 1:14 for French press, 1:13 for AeroPress. Weigh it — a tablespoon of light-roast beans and a tablespoon of dark-roast beans differ in mass by up to 20%, which is why volume-measured coffee is different every morning.

The handbook goes method by method from there, and ends with a two-page diagnosis table: what the cup tastes like, what that means, and the one thing to change next.

About this example

This is a real lead magnet from a coffee roastery, not a mock-up — and it is here because it shows what a finished Unplain PDF looks like when the subject isn’t marketing. The manuscript was written as a plain document. The cover, the contents page, the pagination, the tables, the brand colours and the closing call-to-action page were produced automatically. Whatever you know that your customers don’t, it works the same way.