The science of flavor

Temperature was the central theme of Peng's presentation at this year's World Brewers Cup — an idea drawn from years of roasting and brewing.

"In our cafe in Shanghai, we've installed an infrared thermometer for customers to see how flavor shifts at different drinking temperatures," he explains. "That was the inspiration for this competition."

To Peng, temperature runs through the entire coffee chain — from farm to roast to brew. "Even the warmth between people — good service in a cafe — is its own kind of temperature," he says.

What fascinates Peng most is the journey from raw beans to a cup that expresses the coffee's full potential. Every step, from roasting to brewing, is a chance to experiment, a chance to refine.

"It's a problem of constant permutation and combination," he says. "Every variable changes the outcome. Before the degassing period, for example — carbon dioxide levels shift daily. So your brew method has to adapt. Even the weather on the day you brew can influence flavor."

For him, the joy lies in trial, error, and discovering repeatable formulas. "That's what I love — solving the puzzle, cup by cup."

He entered Jakarta chasing a dream. He left it with a title — and a puzzle he'll keep solving, cup by cup.