Pu’er Coffee

 If you often visit coffee shops for pour-over coffee and ask the barista whether a certain bean tastes better hot or iced, chances are they’ll recommend the hot version. Just yesterday, a friend buying beans complained about this and asked me, “Why do pour-overs have to be hot?” To be fair, the reason baristas recommend hot pour-overs isn’t because hot brews necessarily taste better than iced ones. As I’ve always emphasized, compared to iced pour-overs, hot pour-overs allow you to taste a more complete expression of a coffee’s flavors. Why does a hot pour-over offer more complete flavor? Most coffee shops — including mine — make iced pour-over using a flash-chill method. This means lowering the temperature by adding ice directly into the coffee so you can quickly get a cold cup of pour-over. But since the ice melts while cooling the coffee, the overall concentration inevitably becomes diluted. If we don’t want to end up with a watery cup, we need to increase the coffee concent...

 Green beans start with a raw, grassy aroma, and as they roast under intense heat, everything begins to change. At the moment of “first crack,” the beans expand and their flavor shifts—moving from grassy notes to nutty and chocolatey aromas, eventually developing the smoky depth of a dark roast. But here’s something you may have wondered: Why do some coffees carry a distinct smoky character? Is it an inherent trait of the bean, or just a “little accident” during roasting? Today, let’s break down the origins of coffee’s smoky flavor by looking at roast levels and roasting methods. First Things First: The 8 Roast Levels That Define Coffee’s Flavor Profile A coffee’s foundational taste is largely determined by its roast level. In professional roasting, there are eight levels from light to dark, each with its own characteristics—and its own relationship with smokiness: Light Roast (Around the start of first crack) Strong grassy notes with mild aroma and weak body. Very little d...

 A good cup of coffee should always be enjoyed hot — that’s when you can truly experience its full range of aromas and flavors. This is one of those little mantras I often repeat to my friends. Yet here I am, still wearing short sleeves as autumn slowly creeps in. The air indoors is already getting chilly, and a freshly brewed cup of pour-over coffee cools down far too quickly. Before I know it, the rich aroma fades, the taste dulls, and what was once pure pleasure becomes something “too bland to enjoy, too precious to throw away.” Naturally, the thrifty part of me wonders: can I just reheat it? What Happens When Hot Coffee Cools Down? When coffee is first brewed, hot water extracts a variety of flavor compounds and sets them in motion. We enjoy coffee because we not only smell its aromatic compounds released into the air, but also taste the balance of acidity, sweetness, and bitterness on our tongues. However, as coffee transitions from hot to cold, those sensations change dr...

 When it comes to flannel filters, many coffee lovers may have only seen them in Japanese movies or through videos by Japanese baristas. Compared with the common paper filter and dripper combo, the flannel filter is far less popular outside of Japan. Most people’s first encounter with it comes from Japanese coffee culture itself. That naturally raises the question: why do Japanese people love brewing coffee with a piece of flannel cloth? What makes coffee brewed with flannel so different from coffee filtered through paper? What’s Special About Flannel Filters? If you’ve read my posts before, you’ve probably seen me mention this: flannel filters produce coffee that’s richer and more aromatic . The reason is simple — flannel doesn’t filter out oils and insoluble compounds as thoroughly as paper does. Flannel is a soft, fuzzy fabric that originated in Wales, England. Since its invention, it’s been used in countless applications thanks to its versatility. As a coffee filtration tool,...

 If you’ve ever ordered from an independent coffee shop, chances are the barista reminded you: “Coffee tastes best when it’s hot.” Seasoned coffee lovers even swear by the “15-second golden window” for espresso. But many people wonder — is this just a habit or superstition? What really happens when coffee cools down — does it just taste different, or does it actually go bad ? 🔥 The Science of Heat and Flavor The truth behind “drink it hot” lies in how temperature shapes flavor. When we taste coffee, aroma and flavor are inseparable — aroma comes from volatile compounds, and temperature directly determines how much of that aroma reaches our senses. At higher temperatures — especially around 61–62°C (about 142°F) , widely considered the optimal drinking temperature — the fruity, caramel, and floral notes in the beans are released most vividly. Take the “Mozart” beans from Costa Rica’s Musician Series, for example: right after brewing, the jasmine fragrance hits you first, fo...