Pu’er Coffee

 As a coffee lover and professional, I’ve been guarding this little, aroma-filled café for four years now. My bar counter is like a quiet old friend, accompanying countless people through their early mornings and late nights. Every latte with delicate latte art, every pot of carefully brewed pour-over I handed to customers—what I received in return was the sparkle in their eyes. Coffee was a ritual, a comfort, a silent understanding we all shared. But over the past one or two years, a subtle shift has taken place around me. Several familiar customers, myself included, have gone through similar changes. Those regulars who used to come once a day now only show up two or three times a week, and eventually only on weekends. Take Ms. Wang, for example—the advertising director who relied on a double espresso to survive every workday. Now, when she walks in, she orders only a cup of decaf. She laughs and tells me, “It’s not that I don’t want coffee. I still love the fruity notes of Et...

 Morning—coffee aroma wakes up a new day. Afternoon—a cup of milk tea sweeps away the drowsiness. Late at night—energy drinks keep people going, whether they’re working overtime or gaming. In our fast-paced modern lives, there’s one substance often called the “gentlest stimulant”— caffeine . Without us noticing, it quietly shapes our daily rhythm. It’s the most widely consumed psychoactive substance in the world, with about 90% of adults taking it in one form or another. Caffeine can boost alertness, but it may also bring health risks. So how do we use this “double-edged sword” wisely? Let’s take a scientific look. What Exactly Is Caffeine? Caffeine is a natural alkaloid, chemically known as 1,3,7-trimethylxanthine , and it appears in over 60 plants including coffee beans, tea leaves, cocoa beans, and guarana berries. In nature, caffeine is a plant’s “secret weapon.” It can paralyze leaf-eating pests, protecting the plant, while its presence in nectar helps attract pollinator...