All the Random Variables in Pour-Over Coffee Many brewers experience this: Same recipe, same dripper, same grinder — different cup. This often leads to claims that pour-over coffee is “mysterious” or “unpredictable.” From an engineering perspective, these are not mysteries — they are unaccounted variables. What Are Random Variables? In pour-over coffee, random variables are…

Why Filter Paper Matters More Than You Think In pour-over coffee, most discussions focus on grinders, grind size, water temperature, and pouring technique. But one variable is often underestimated: filter paper. Filter paper is not “just a consumable.” It behaves like a precision engineering component inside the brewing system—shaping water flow, air exchange, fines migration,…