Pu’er Coffee

 When people order espresso-based drinks at cafés—especially milk drinks topped with beautiful latte art—it almost always brings a small moment of joy. The unspoken rule of “let the phone take the first sip” naturally kicks in, and a photo is taken before anything else. Sometimes, the visual impact of latte art even outweighs the actual flavor experience of the coffee. And although I personally care more about taste, I have to admit that when a cup comes with an intricate, well-balanced, and beautifully integrated design, it still makes me genuinely excited and pleasantly surprised. So this raises an interesting question: how did latte art, built on espresso, start becoming popular in the first place? Today, let’s take some time to talk about that. I did quite a bit of research online, and to be honest, there doesn’t seem to be a single, definitive historical account. However, its development can generally be traced back to the second half of the 20th century. Espresso machines w...

 If you pay attention to coffee gear, you’ll notice that many tools come in a wide range of materials. Take drippers, for example—you can find them made from resin, ceramic, glass, or stainless steel. But when it comes to milk frothing pitchers, the choice seems almost unanimous: stainless steel. This raises a natural question—are other materials really unsuitable? And if so, why has stainless steel become the near-universal standard? Today, let’s take a closer look at the physical properties and practical considerations that have led to this seemingly one-sided outcome. A truly good milk pitcher needs to meet several strict requirements: excellent heat transfer, controllable temperature rise, durability and strength, and proper hygiene. These demands alone narrow the list of viable materials considerably. Once you understand the core purpose of a milk pitcher and what it must do well, the answer becomes fairly obvious. Heat Conductivity Comes First The most critical factor is he...