"But inspecting the grounds tells you why—and how to make the next cup perfect."… The morning sun cut through the steam of the kitchen as Julian poured the last splash of water over his pour-over cone. His friend, Maya, sat across the counter, taking a cautious sip from her mug. “It’s… fine,” Maya said, her tone polite but clearly unconvinced. “A bit sour, maybe? Honestly, I bought these high-altitude Ethiopian beans thinking they’d taste like jasmine and bergamot, but this tastes flat.” Julian didn’t grab the mug. Instead, he pulled the paper filter out of the dripper and set it gently on a small ceramic tray between them. “If you want to know what actually happened in that cup, stop looking at the liquid,” Julian said, nodding toward the bed of dark, wet coffee bed. “The spent grounds never lie.” Maya leaned in, intrigued. “The leftover trash?” “The byproduct tells the whole story,” he said, tapping the edge of t...