You need: a grinder, a kettle, four wide-rimmed glasses, a spoon. Grind 12g of coffee per glass, medium-coarse. Pour 200g water at 94°C. Wait four minutes. Break the crust with the spoon — three gentle pushes through the bloom. Taste at six, ten, and twenty minutes. Write what you notice. The flavour of a coffee is whatever you decide to call it, but the act of writing changes what you taste.