Roasting guides

First crack: what it is and what to do when you hear it — First crack is the loudest landmark in a roast. Here is what is going on inside the bean, and why the minutes after it matter more than the minutes before.
Development time ratio: the number that explains most flavor problems — How long you let a coffee roast after first crack, as a share of the whole roast, tells you more about sourness and bitterness than the final temperature does.
Rate of rise (RoR): reading the line under your roast curve — RoR is how fast the beans are heating at each moment. Learn what a healthy line looks like, what a crash or a flick means, and how to fix each one.
Weight loss in roasting: what the percentage tells you — Weigh the coffee before and after the roast and you get a number that is easy to measure and surprisingly telling. Here are the usual ranges and what to do with them.
How much green coffee should you load in the drum? — The charge weight on the machine's spec sheet is a ceiling, not a recipe. Why a smaller load often gives a better roast, and how to find yours.
Why is my roast taking so long? — Roasts that run far past the usual time tend to taste flat and baked. Common causes, from gas pressure to airflow, and how to check them one at a time.
Roasting dark without burning the beans — The gap between a medium-dark and a burnt roast is only a few seconds. How to see it coming, what changes in the drum, and how to plan the drop.
What to write in a roast log so it's useful later — A log you never read is just paperwork. What to record on every batch, what to skip, and how to compare two roasts of the same coffee.
Cupping notes that actually teach you something — How to taste your own roasts side by side, what to write down, and how to tie what you taste back to what you did in the drum.
How long should roasted coffee rest before you sell or brew it? — Freshly roasted coffee gives off gas for days. Typical resting times for filter and espresso, why it matters, and how to test your own.
Roasting a new green coffee for the first time — A practical way to learn a coffee you haven't roasted before: start from what you know, change one thing, and keep notes so the third batch is better than the first.