Agitative
The Journal
How to Scale a Coffee Recipe Up or Down Without Breaking It
The ratio math for brewing a bigger batch is simple multiplication, but a few things don't scale as cleanly as dose and water do — a worked example scaling a recipe 4x, plus what actually changes at very large and very small batch sizes.
Caffeine Content Is Arithmetic: Here's the Honest Math
No mystery, no personal recommendation — just dose times an average figure, plus a range because the average is an average. A worked running total across a day, and where this arithmetic stops and a doctor's advice starts.
Water and How It Changes the Cup, Not Just What's In It
Water isn't a passive ingredient that either tastes fine or doesn't — its mineral content is an active participant in extraction. A worked example holds dose, ratio, and grind identical and changes only the water, to show how much of the final reading that alone can move.