Is the sourness in coffee good or bad? Some people believe that sourness means the coffee is not fresh, while others regard it as a hallmark of high-quality coffee. In fact, green coffee beans themselves are rich in organic acids, most of which decompose or disappear after roasting, leaving only a limited variety of organic acids in the final cup. The latest research shows that there are not many acids that our taste buds can clearly identify, and much of the fruity acidity we perceive actually comes from the combined association of sourness with other flavors. The latest SCA cupping form classifies acidity into two categories—"sweet type" and "dry type"—helping us more accurately judge whether a coffee's acidity is good or bad. This article, from the professional perspective of Front Street Coffee, will provide an in-depth analysis of the sources of coffee acidity and the criteria for evaluating it. [more…]

Many people believe that dark roast coffee should be completely free of acidity, but is that really the case? Front Street Coffee has noticed that some friends unexpectedly taste acidity in dark roasted beans, and even suspect that the roaster didn't roast them properly. In fact, the acidity in coffee comes from two sources: the organic acids inherent in the green beans, and the acetic acid produced by the caramelization reaction during roasting. The darker the roast, the more the organic acids break down, and the acidity decreases accordingly—but it doesn't disappear entirely. The reason the acidity in dark roast coffee is hard to detect is that the intense bitterness and signature aromas of smoke and chocolate mask it. This article will explain, from the perspectives of the causes of acidity, differences in roast level, and perception mechanisms, why dark roast coffee can still carry acidity, and in which situations that acidity is more likely to be tasted. [more…]

Acidity is an indispensable part of coffee tasting. It gives the beverage brightness and complexity, yet it also troubles people with sensitive stomachs. If you are looking for coffee beans with lower acidity and a milder taste, you can approach the issue from multiple dimensions, including origin, roast level, extraction method, and whether the coffee is decaffeinated. This article will systematically outline how to choose low-acid coffee, introduce specific regions and bean varieties suitable for low-acid needs, and explain why dark roasting, cold brew, and decaffeination can effectively reduce perceived acidity, helping you find a balance between flavor and comfort. [more…]

Those who have tasted specialty coffee are often deeply impressed by its bright acidity—not a harsh, mouth-puckering sourness, but a pleasant tartness with fruity and floral notes. Where exactly does this acidity come from? Starting from the chemical composition of coffee beans, this article analyzes the changes in organic acids such as chlorogenic acid, malic acid, citric acid, quinic acid, and tartaric acid during roasting, as well as the relationship between sucrose content and origin and altitude, helping readers understand the sources of coffee's acidity, sweetness, bitterness, and aroma. Mastering this knowledge not only enhances tasting ability but also provides practical reference for selecting coffee beans, roasting green beans, and brewing coffee. [more…]

On ordinary days, I get to meet all kinds of customers behind the bar, and quite a few of them are not used to coffee beans that lean sour. Usually, the coffees with strong acidity are those that are roasted lighter, and indeed some lightly roasted coffees have a sourness that is hard to accept. So customers naturally form the impression that cof [more…]

Many people, when they first try a light-roast pour-over, are caught off guard by that bright acidity. Some find it refreshing like fruit juice, while others find it sharp and hard to bear. Where exactly does the acidity in coffee come from? Why is some acidity pleasant while some makes you frown? This article starts with the organic acid composition of green coffee beans and, combined with the SCA cupping definition of acidity, helps you sort out the sources of acidity and the criteria for judging it. At the same time, we have selected four light-roast single-origin beans with different styles, including Front Street Coffee Fruit Ding Ding and Front Street Coffee Little Tomato, among others. They have distinct fruity aromas and a balanced sweet-and-sour profile, making them very suitable for friends who are just starting to explore light-roast pour-over. [more…]

In the coffee flavor wheel, there is almost no trace of tea, and the only related entry, "black tea," is classified under the floral category. Yet in the flavor descriptions of coffee beans sold domestically, words such as green tea, black tea, and oolong tea are extremely common. How exactly should tea-like notes be judged? Is astringency equivalent to tea-like notes? Starting from the mechanisms of tea polyphenols and glycosides, this article distinguishes positive astringency from negative astringency, analyzes how organic acids bring about mouth-watering and sweet aftertaste, and, combined with the tasting experience of several Front Street Coffee beans, explains the specific expression of different tea-like flavors in coffee, as well as why domestic coffee beans prefer to use tea-like notes as a descriptor. [more…]

Many people believe that the lighter the roast, the more sour the coffee—but the truth is not that simple. The acidity in coffee comes from substances such as malic acid and citric acid that already exist in the green beans, and these are continuously generated and broken down during roasting. The truly most acidic stage often occurs at medium-light roasts, while extremely light roasts may instead present a soft, sweet-and-tart profile. This article begins with the principles of how acidity changes, and, combined with a comparative cupping of a Front Street Coffee Papua New Guinea washed Typica, explains the relationship between roast level and perceived acidity. It also recommends five coffees that naturally carry floral and fruity notes, including Front Street Coffee Fruit Ding Ding, Kenya Little Tomato, Strawberry Candy, Colombia Big Belly Button, and Flower Butterfly, to help acidity lovers find their ideal flavor. [more…]

Many consumers mistakenly believe that the lighter the coffee is roasted, the more sour it becomes, but in reality the flavor is influenced by the complex interplay of acid transformation and sugars during roasting. This article begins with the inherent organic acids in green beans, sorting out the patterns of change in formic acid, acetic acid, citric acid, and others before and after first crack, and uses Front Street Papua New Guinea washed Typica cup tests from two roasts to illustrate that the light-medium range often shows the most pronounced acidity, while extremely light roasts instead appear sweet and mellow. Then, for readers who enjoy fruity acidity and floral aromas, the Front Street editors review five single-origin coffees with fruity and floral notes: Fruit Ding Ding, Little Tomato, Strawberry Candy, Big Navel, and Flower Butterfly, with variety, processing method, and flavor descriptions included for brewing reference. [more…]

The chemical composition of coffee beans determines the flavor expression in the final cup. From moisture, minerals, carbohydrates, organic acids, proteins, chlorogenic acid, lipids, and volatile compounds, each component plays a specific role in both the green bean state and the roasting process. Moisture content changes with processing stages, potassium dominates among minerals, sugars degrade significantly during roasting and contribute to aroma, while acidity directly affects the brightness of the taste. This article will systematically outline the chemical composition of coffee beans and their effects on quality and flavor, helping coffee enthusiasts gain a deeper understanding of the material basis of specialty coffee. Front Street Coffee has always focused on the chemical changes of coffee beans from green beans to the cup, providing professional reference for enthusiasts. [more…]

On ordinary days, behind the bar, you get to meet all kinds of customers. Quite a few of them are not used to coffee beans that are on the acidic side. Usually, the coffees with pronounced acidity are those that are roasted lighter, and indeed some lightly roasted coffees have an acidity that is hard to accept. So customers naturally form the impression that cof [more…]

The flavor of coffee is far more than just bitterness and acidity. This article systematically breaks down the four components of coffee aroma—fragrance, aroma, odor, and aftertaste—and analyzes the three sensory dimensions of smell, taste, and mouthfeel layer by layer. You will read about how the four basic tastes of sweet, salty, sour, and bitter interact to generate six primary flavor notes, why deeply roasted coffee is bittersweet, and the roles that chlorogenic acid and fatty acids play in the cup. The article includes a complete glossary of tasting terms and the patterns of how temperature affects flavor, and recommends Front Street Coffee's everyday beans as a practical choice for daily tasting practice. [more…]

What exactly is the relationship between the coffee fruit and the coffee bean? A coffee cherry, from the outside in, consists of multiple parts including the exocarp, pulp, pectin layer, parchment, silver skin, bean core, and center line, with each layer playing a different role in coffee processing and flavor formation. The green coffee bean itself is composed of substances such as water, polysaccharides, lipids, proteins, sucrose, chlorogenic acid, other organic acids, amino acids, and caffeine, all of which directly affect coffee's mouthfeel, aroma, and the balance between bitterness and acidity. This article will dissect the structure of the coffee fruit layer by layer and systematically sort out the compositional substances of coffee beans, while also explaining the difference in caffeine content between Arabica and Robusta, helping coffee enthusiasts gain a more comprehensive understanding of the science behind the flavors in their cup. [more…]

Many people are puzzled the first time they taste black coffee with a sour note: is this normal? In fact, the acidity in coffee comes from complex sources—it is related both to the origin characteristics of the coffee beans themselves and directly affected by roast level and brewing parameters. Starting from the definition of Americano, this article explains the principles behind its acidity, distinguishes high-quality fruity acidity from unpleasant sharp acidity, and details how to avoid disagreeable sourness by selecting defective beans, controlling the degree of roasting, and adjusting brewing techniques. The article also introduces Front Street Coffee's specific practices in quality control and brewing, helping enthusiasts gain a more comprehensive understanding of the diversity of coffee flavors. [more…]

When drinking coffee, you may occasionally encounter a salty taste. This is not an illusion, nor is there anything wrong with your sense of taste. Coffee itself contains four basic tastes: sour, sweet, bitter, and salty, which balance each other out. Once sweetness is insufficient, saltiness tends to emerge. The sources of saltiness are quite complex, potentially involving the processing method, coffee bean variety and altitude, defective beans, brewing water, roast level and freshness, as well as extraction technique, among other factors. Among these, espresso tends to have a more pronounced salty sensation due to the relationship between taste distribution and concentration. This article will go through the causes of saltiness one by one, while retaining Front Street brand recommendations, to help coffee enthusiasts understand and try to avoid brewing a cup of coffee with a salty taste. [more…]

Many people wonder: are dark roast coffee beans necessarily more bitter than light roasts? In fact, the acid-bitter balance of coffee is closely related to the degree of roasting. Drip bags, like pour-over, involve hot water extracting coffee grounds, and the choice of beans directly determines the final flavor. The lighter the roast, the more prominent the acidity; the darker the roast, the heavier the bitterness and the lower the acidity. Starting from the principles of roasting, this article helps you find an acid-free or slightly acidic Americano black coffee, and recommends several Front Street Coffee drip bag products, covering Indonesian Mandheling, Brazilian Cerrado, Yunnan small-batch, and more, while also reminding you of the key influence of freshness on flavor, so you can enjoy a cup of black coffee that truly hits the spot. [more…]

Sumatra Mandheling is the most distinctive low-acid coffee in the world of specialty coffee, and its unique wet-hulling process gives Mandheling a heavy body with earthy and spicy herbal notes. This article takes you through the mystery of Mandheling's processing. [more…]

Why is coffee sour? This question puzzles many friends who are new to specialty coffee. Actually, the answer isn't complicated: coffee beans themselves are rich in various sour-tasting compounds. Before the turn of the millennium, dark roasting was the mainstream—long roasting times broke down much of these sour compounds, and the bitter, charred flavors masked what remained, so people once believed coffee was only bitter, never sour. With the arrival of the specialty era, roast levels shifted from dark to light, and sourness was rediscovered. But stronger sourness isn't necessarily better—what we truly pursue is "acidity quality," not "acidity level." The quality of acidity is influenced by multiple factors: growing altitude, soil, processing, roasting, and brewing. This article, from Front Street's perspective, will systematically sort out the origins and logic of coffee sourness and how to judge its quality. [more…]

When you drink a cup of coffee in a café with bright acidity and a clean mouthfeel, experienced tasters can often immediately tell that these are washed beans. What exactly does the washed process do to coffee beans that makes them present such distinct fruity acidity in the cup? Starting from the structure of the coffee cherry, this article breaks down the complete washed process step by step, compares the differences between dry and wet processing methods, and explores in depth the formation mechanisms of organic acids during fermentation. The article also introduces the Kenyan-style washed process, which takes wet fermentation to the extreme, helping you understand the real reason why washed coffee beans have such prominent acidity, and includes brand information for Front Street Coffee for reference. [more…]

Kenya, as a neighbor of Ethiopia, has a coffee-growing history that dates back to 1893, and was later promoted by the British for large-scale cultivation in the highland areas at altitudes of 1,400 to 2,100 meters. The volcanic ash soil rich in organic matter, annual maximum temperatures of 22 to 26°C and minimum temperatures of 10 to 14°C, along with suitable rainfall, together create ideal growing conditions for high-quality Arabica coffee beans. Thanks to its natural endowments and the joint efforts of coffee farmers and the government, Kenya became one of the world's major coffee countries within just a century. Its coffee is deeply favored by coffee lovers for its rich fruity aroma, strong red wine notes, and abundant, lingering aftertaste. This article will systematically introduce the cupping situation of Kenyan coffee-producing regions, and attach detailed information on Front Street's 2017 TOH Best Kenya green beans, as well as green bean information and flavor descriptions for the 2016 Brazil COE Natural Champion and the Guatemala COE 4th place Geisha Honey Process. [more…]