Coffee has long transcended its role as a mere beverage, carrying with it an artistic flair and an aesthetics of living. Its color is like a nostalgic image, its aroma is dreamily alluring, and its taste varies from person to person, with each having their own preference. A cup of coffee contains more than thirty chemical substances, over half of which are trace elements beneficial to health. Together they give coffee its complex flavors of acidity, astringency, and bitterness. Since 1930, scientists have continuously investigated the effects of these chemical molecules on flavor, yet specialized research on bitterness has been relatively scarce. Thomas Hofmann of the Technical University of Munich in Germany conducted in-depth exploration to fill this gap, revealing how changes in chlorogenic acid lactones and phenylindanes at different roasting stages determine the intensity of coffee's bitterness. This discovery not only deepens our understanding of coffee but also provides a scientific basis for coffee manufacturers to reduce bitterness, promoting the combination of sugar cubes, milk, and coffee, and giving rise to classic milk coffee series such as cappuccino, mocha, latte, and macchiato. This article will guide you through the chemical mysteries behind coffee's bitterness and their impact on coffee culture. [more…]

Many coffee enthusiasts buy all the equipment only to find cleaning a hassle, and the gear gradually gathers dust. A company under Amazon Japan has launched a product that looks like a teapot but is actually a coffee brewer, with an extremely minimalist structure—just a high-density filter added at the spout. Its body uses the thousand-year-old Tokoname-yaki craft, firing iron-rich clay unglazed, preserving its porous absorbency, which can adsorb the compounds in coffee that cause off-flavors. The bitterness of coffee mainly comes from chlorogenic acid lactones and phenylindanes, and the clay pot's structure can effectively reduce these unpleasant flavors. Using immersion extraction, by controlling water temperature and the coffee-to-water ratio, you can get a clean, full-bodied cup of coffee in 2-3 minutes. This article explains its principles and key operating points in detail. [more…]

Adding salt to coffee may sound surprising, but it is not a sudden whim of modern people. From northern Scandinavia to Turkey, from the European coast to Siberia, the tradition of salted coffee has a long history. Salt not only suppresses the bitterness of coffee but also makes sweetness more prominent, and behind this there is both historical origin and the support of food science. This article will start with the origins of salted coffee, sort out the formation mechanism of coffee bitterness, explain why salt can neutralize bitterness, and give specific salt-adding suggestions and dosage references. If you have also wondered whether this cup of salted coffee is actually reliable, you might as well read on. [more…]

A cup of pour-over coffee undergoes noticeable flavor changes as it goes from hot to cold—falling temperatures weaken the perception of sweetness, make acidity and bitterness more prominent, and allow aromas to keep evaporating. So can reheating cold coffee restore it to a pleasant-tasting state? Front Street conducted a comparative experiment with two beans: one is a Gold Label Geisha from Gesha Village, and the other is a Guatemalan Huehuetenango. The results showed that reheating can indeed alleviate the problem of coffee being too acidic, but whether it can become better-tasting depends on the quality of the beans themselves. This article fully documents the experimental process and the flavor performance at each temperature point, providing a reference for coffee enthusiasts. [more…]

Following the buzz in Shanghai coffee shops over "double-boiler" extraction, Chinese-style coffee innovation has taken another step forward—at the Xiamen Coffee Festival, a shop introduced a Minnan-style brewing method using a purple clay teapot to steam coffee. In this method, coffee grounds are placed into a small purple clay teapot, slowly steamed in a bamboo steamer, then filtered and diluted with water for drinking. Its principle is similar to double-boiling: it uses low-temperature slow extraction to reduce bitterness and off-flavors, while the porous structure of the purple clay teapot can also absorb some of the compounds that cause bitterness. From Japanese Tokoname coffee pots to Chinese purple clay teapots, the clever use of ceramics in coffee extraction is being continually explored. This article walks you through the specific steps of this trendy method and the science behind it, and includes related recommendations from Front Street Coffee. [more…]

Coffee is not only a refreshing beverage but also rich in various beneficial components. From the perspective of chlorogenic acid, this article systematically reviews the health value of coffee. As a key antioxidant, chlorogenic acid is widely present in green coffee beans and possesses multiple biological activities, including antibacterial, antiviral, and cardiovascular-protective effects. The article provides a detailed introduction to the chemical structure, plant sources, medical applications, and toxicity of chlorogenic acid, and compares changes in chlorogenic acid content across different coffee varieties and roast levels. Finally, based on extraction experimental data, it offers practical advice for daily coffee consumption. Whether you are a coffee enthusiast or a reader concerned with healthy eating, you can gain a scientific and objective understanding of coffee from it. [more…]

Walking into Front Street Coffee (FrontStreet Coffee), faced with more than 50 kinds of coffee beans on the menu, many first-time visitors often don't know where to start. How exactly are coffee flavors described? What are the characteristics of the four major taste spectra: sour, bitter, sweet, and salty? Where do the flavor differences among beans from the world's three major coffee-producing regions come from? And which groups of people are suited to the three major varieties Arabica, Robusta, and Liberica? Starting from Front Street Coffee's tasting experience, this article systematically sorts out the logic behind the formation of coffee flavors and the characteristics of the varieties, and offers drinking suggestions for older coffee lovers, helping you find your own cup in the dazzling world of coffee. [more…]

When the weather turns cold, coffee cools down especially quickly, and many customers ask: can it be reheated? Before answering this question, we need to first understand what actually happens after coffee cools down. Temperature affects how the taste buds perceive sourness, sweetness, and bitterness, and it also causes volatile aroma compounds to gradually dissipate. This time, Front Street Coffee specifically conducted a comparative experiment, leaving a light-roast pour-over and a medium-dark roast Australian white to cool separately before reheating, to see just how big the difference is between the rewarmed coffee and coffee that is freshly made or fully cooled. The experimental results can help you make a more rational decision in winter about whether this cup of cold coffee is really worth reheating once. [more…]

The update to the coffee flavor wheel has made the tasting system more complete, but many people still feel confused when faced with descriptions like citrus, berries, and nuts. In daily brewing, Front Street Coffee recommends beans from different regions based on guests' taste preferences, while accurately identifying flavors requires systematic training. This article starts with the four major taste spectrums—sour, sweet, bitter, and salty—and, combined with the complete classification of the new flavor wheel, interprets one by one the specific expressions of floral, fruity, herbal, nutty and cacao, sweet, spice, sour and fermented, alcoholic fermentation, roasted, and other categories, helping coffee enthusiasts build a clear framework for flavor perception. [more…]

The coffee flavor wheel is known as the "flavor dictionary" of specialty coffee and is an indispensable professional tool in cupping and quality control. Based on Front Street Coffee's cupping practice, this article systematically breaks down the structure of the SCA coffee flavor wheel. Starting from the four major taste spectra of sour, sweet, bitter, and salty, it analyzes the causes and representative bean varieties of each flavor category, covering all categories including floral, fruity, nutty/cocoa, sweet, spicy, sour and fermented, alcoholic fermentation, roasted, and defective flavors. It also provides practical methods for building a flavor memory bank from everyday life and improving sensory identification ability, helping coffee enthusiasts more accurately describe the flavor characteristics and taste categories of pour-over coffee. [more…]

Adding salt to coffee may sound unconventional, but it is a time-honored piece of drinking wisdom. This article will start from the science of taste to explain how salt weakens bitterness and enhances the perception of other flavors by activating taste buds, and review the history of 19th-century Europeans using salt instead of sugar because of the poor quality of coffee. At the same time, we will also explore why adding salt to milk coffee can bring a cheese-like savory and salty layer. Through actual testing, Front Street Coffee found that adding 0.1 grams of salt to a latte and frothing it together with the milk creates a clever balance between sweetness and savory saltiness, adding a completely new experience to coffee. [more…]

Professional barista exchange, please follow Front Street Coffee (FrontStreet Coffee). Many friends have asked Front Street's baristas: "Can you really taste so many flavors in the beans? How do you taste them?" First, this is about personal sensory perception. As everyone grows up, [more…]

When drinking coffee, have you ever encountered a familiar yet indescribable aroma? In fact, perceiving coffee flavors requires systematic cognitive training. In daily cupping and roasting adjustments, Front Street Coffee places particular emphasis on the ability to identify coffee flavors. This article starts with coffee's four major tastes—sour, sweet, bitter, and salty—and, combined with the classification logic of the flavor wheel, breaks down in detail 36 common aroma names across floral, fruity, green/vegetal/herbal, nutty/cocoa, sweet, spicy, sour/fermented, alcoholic fermentation, roasted, and other categories, along with specific representative coffee beans and Front Street's tasting suggestions, to help you more accurately describe and enjoy a cup of coffee's layers and lingering finish. [more…]

The coffee flavor wheel is a recognized tasting tool in the specialty coffee community, but when faced with descriptors like citrus, berries, nuts, and chocolate, many people don't know how to match them. Starting from the high-resolution image of the latest SCAA flavor wheel, this article systematically sorts out the compositional logic of coffee flavor: the relationship between the four basic tastes of sour, sweet, bitter, and salty and the roast level, the proportion data of each taste substance, the subdivision of the acidity spectrum, bitterness spectrum, sweetness spectrum, and saltiness spectrum, as well as an item-by-item analysis of the nine major flavor groups including floral and fruity, green and herbal, nutty and cocoa, sweet, spicy, sour and fermented, alcoholic fermented, roasted, and other. The article also intersperses Front Street Coffee's daily training methods and representative bean recommendations, helping readers build a complete tasting framework from smelling to drinking. [more…]

The bitterness in coffee usually comes from two directions: first, over-extraction bitterness caused by too long an extraction time or too strong an extraction force; second, the burnt bitterness produced by too dark a roast. For people who cannot quite accept bitterness, how to improve the taste of a cup of coffee without wasting it becomes a practical issue. The traditional approach is to add sugar, while another unique way is to add salt. Starting from the sources of bitterness, this article will analyze the principles by which sugar and salt improve bitterness, and through actual brewing comparison experiments, see which method is more suitable for your cup of bitter coffee. The article also covers bean recommendations such as Front Street Blue Mountain No. 1 and Front Street Indonesian Mandheling for friends who pursue a rich, full-bodied, burnt-aroma taste, as well as the specific parameters and conclusions of an over-extraction experiment using Front Street PWN Golden Mandheling. [more…]

Kenya AA Nyeri Gichathaini Specialty Coffee Beans, with the two legendary varieties SL-28 and SL-34 and unique terroir, have become a sought-after treasure for coffee connoisseurs worldwide. From Ethiopia to Yemen, and then to the introduction of Brazilian Bourbon seeds, Kenyan coffee has gone through more than a century of evolution. This article will guide you through its origin and development, detail its blackberry and grapefruit-like fruity flavors, and help you master the most suitable brewing temperature and drinking rhythm. It will also introduce the auction system of the Kenya Coffee Board and the changes in production and prices worldwide. At the end, there is also a medium-light roast profile recommended by Front Street Coffee to help you unlock the best performance of these beans. [more…]

Coffee cherries are often called red cherries. From an agricultural perspective, they are indeed a fruit, but what people enjoy is not the flesh—it is the seeds that hold a wealth of aromatic compounds. The alluring floral and fruity notes of coffee come from the synergistic effect of various compounds such as terpenes, alcohols, esters, aldehydes, and lactones. Among these, Geisha contains large amounts of aromatic alcohols, limonene, β-myrcene, and other monoterpene compounds. Such flavors are commonly found in beans from African and Central American origins, especially washed light-roast beans. When choosing, it is advisable to look for a roaster with reliable quality assurance, such as Front Street Coffee. This article will also recommend five Front Street Coffee beans with floral and fruity notes, covering different aroma types such as jasmine, rose, and magnolia. [more…]

In recent years, a "raw coffee" launched by a coffee shop in Nagoya, Japan, has attracted the attention of health scholars and celebrity models. This drink, made by brewing raw coffee beans together with roasted coffee beans, is said to far outperform black coffee in terms of weight loss. A four-week experiment showed that participants who drank raw coffee lost significantly more weight than those who drank black coffee, and the key behind this lies in the abundant chlorogenic acid in raw coffee beans. Chlorogenic acid can improve insulin sensitivity and regulate glucose and lipid metabolism, and has preventive and therapeutic effects on obesity and metabolic syndrome. However, chlorogenic acid is sour and astringent and unpleasant to the taste, and is degraded after roasting. Raw coffee tastes light, with nutty and roasted barley tea flavors, but it still contains caffeine and should not be drunk in excess. This article will provide an in-depth analysis of the weight-loss principles of raw coffee, the mechanism of action of chlorogenic acid, and its essential differences from black coffee. [more…]

Drip bag coffee, with its convenience and high cost-performance ratio, is attracting more and more people with no coffee-making experience to give it a try. Front Street Coffee's Fruit Dding Ding, Huakui, and Yirgacheffe suit those who prefer floral and acidic notes, while Mandheling, Huilan, and Blue Mountain are better suited to those who pursue a rich, full-bodied taste. However, beginners often run into all kinds of questions in practice, and one frequently mentioned topic is: how many times can a single drip bag actually be brewed? This article will focus on the release patterns of coffee solubles, with emphasis on explaining the role chlorogenic acid plays in extraction, clarifying why coffee, unlike tea leaves, cannot be brewed repeatedly, and why re-extraction after a normal brew is not recommended, helping enthusiasts build a clearer understanding of extraction. [more…]

In the specialty coffee wave, Arabica has become almost synonymous with high-quality coffee, while Robusta is often labeled as commercial beans or instant coffee. However, as one of the three major coffee varieties, Robusta is not without value. Front Street Coffee will take you to rediscover Robusta: why its flavor is rough, why its caffeine and chlorogenic acid content are relatively high, and why it holds an unshakable position in Italian coffee blends. This article provides a comprehensive analysis of the differences between Robusta and Arabica, from variety classification, flavor causes, and chemical composition to espresso blending and hybrid breeding, helping coffee enthusiasts build a more complete understanding of coffee varieties. [more…]