Get into a steady routine. Use a scale to weigh your coffee and water every time—eyeballing is a recipe for inconsistency. Preheat your Chemex with hot water while you grind. Keep a timer on your phone. And track what you change so you can replicate the good brews.

A simple starting point that works for most: 33g coffee, 500g water, water just off boil, grind like coarse sea salt, total brew time 3:45. From there, adjust one thing at a time—a click finer, a few grams more, a faster pour—until it tastes the way you like.