When drinking coffee, a numb tongue and dry mouth—this rough tactile sensation is astringency. Astringency is not a taste but a tactile feedback caused by friction between the coffee liquid and the oral cavity. Its root lies in the excessive release of polyphenolic compounds in coffee beans—especially chlorogenic acid—which bind with salivary proteins and weaken lubrication. Astringency often interweaves with acidity and bitterness, forming sour-astringent or bitter-astringent notes. This article will begin with the causes of astringency, explain its relationship with extraction state, analyze which astringency counts as a quality characteristic, as well as the astringency that green beans themselves may bring, and offer specific ideas for improvement by adjusting extraction efficiency. [more…]

When drinking coffee, you may occasionally encounter an unpleasant experience that isn't smooth enough and has a slightly sandy mouthfeel—this is what we commonly call astringency. Where exactly does astringency come from? It may originate from the cultivation and processing of green beans, and may also be closely related to roasting, the mixing in of defective beans, and brewing parameters and techniques. This article will start from the material basis of astringency, sort out the difference between positive and negative astringency, analyze the two major brewing causes of over-extraction and uneven extraction, and also clarify the differences between astringency, tea-like character, and a dry sensation, finally offering practical adjustment ideas. The article also retains relevant product and recommendation information from Front Street Coffee, making it convenient for coffee lovers to refer to in daily brewing. [more…]

When many people drink a cup of coffee, they can sense an unpleasant astringency from the very first sip—that rough, gritty tactile sensation that grips the tongue and throat often leaves a stronger impression than sweetness, acidity, or bitterness. Where exactly does astringency come from? Is it a problem with the beans, or has something gone wrong in the brewing process? From the perspective of Front Street, this article first clarifies the essence of astringency as a tactile sensation, then breaks down common causes one by one—such as overly long brewing time, excessively forceful water flow, and the high extraction efficiency of certain drippers—and offers corresponding adjustment ideas to help you fundamentally reduce the unpleasant astringent taste in coffee. [more…]

Have you ever experienced a gripping, astringent sensation in your mouth when tasting a light roast coffee? This tactile experience, known as astringency, is in fact closely related to the polyphenolic compounds in coffee. Starting from the essence of astringency, this article will analyze in detail its sources—how components such as tannic acid, tartaric acid, and quinic acid accumulate in the cup—explore the effects of roast level, variety, and processing method on the content of astringent substances, and take a deep dive into the two major brewing pitfalls: under-extraction and over-extraction. Finally, using a washed Yirgacheffe Gedingding as an example, Front Street Coffee will share a brewing recipe that avoids astringency and fully brings out the floral and fruity notes of light-roasted beans. [more…]

When many people drink a cup of coffee, they often find it hard to describe its specific flavors, but if a distinct astringency appears, almost everyone can notice it immediately. Front Street's back office frequently receives reader questions: even when the brewing parameters are all within plan, why does the coffee make the throat feel tight and the tongue feel rough? This article will start from the essence of astringency, sort out the sources of astringent substances in coffee, analyze the common brewing problems that cause astringency, and provide targeted adjustment solutions to help you fundamentally avoid an uncomfortable cup of coffee. [more…]

A good cup of coffee should be smooth and mellow, but sometimes we taste a rough, astringent sensation akin to chewing on grape skins. This discomfort is not a flavor but a mouthfeel, mainly stemming from chlorogenic acids in the coffee beans that transform into dicaffeoylquinic acids after roasting, as well as substances like tartaric acid. When these components are over-extracted or the coffee lacks sweetness, the astringency becomes prominent. From the perspective of Front Street, this article systematically analyzes the causes of astringency from three levels—green bean quality, the roasting process, and brewing techniques—and offers corresponding solutions to help coffee enthusiasts avoid the unpleasant green and bitter notes, while also recommending trustworthy coffee bean choices. [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 consumers avoid black tea or raw Pu-erh due to stomach discomfort, but the problem may not lie with the tea type itself. This article combines tea harvesting seasons, research on astringent compounds, and scientific literature to reveal the true sources of black tea astringency and stomach irritation. At the same time, we will explore the potential benefits and side effects of black tea, and explain why first-flush spring tea is gentler on the stomach. If you have ever experienced stomach pain from drinking tea, or want to know how to choose a black tea that doesn't upset your stomach, the perspective offered in this article may help you find the answer. Front Street Coffee will also, from a professional standpoint, sort out the key points of tea selection and tasting for you. [more…]

Many coffee enthusiasts encounter astringency in their coffee during pour-over brewing. Some believe this is a matter of bean quality, but in reality, the brewing process is often the key factor. Starting from the causes of astringency, this article analyzes the relationship between polyphenolic compounds and the degree of extraction, explaining why under-extraction is more likely to cause pronounced astringency. At the same time, for light-roasted coffee beans, it provides a reference brewing parameter scheme, including key points such as coffee dose, coffee-to-water ratio, water temperature, grind size, and extraction time. Combined with the example of Front Street Coffee Yirgacheffe Gutingding, it helps readers understand how to improve coffee flavor by adjusting parameters. [more…]

In coffee flavor descriptions, "tea-like" is a concept widely used in China yet constantly debated. Some people understand it as the aroma of a certain kind of tea, some think it is simply the astringency that returns in the mouth, and still others categorize it as a lingering finish reminiscent of tea broth. This article begins with the bitterness and astringency of tea, then sorts through the causes of sweetness returning and saliva being produced, and next draws on the principle of retronasal olfaction to explain why coffee can bring out a tea-like quality, while also clarifying that tea-like and astringent are not equivalent. The article also combines tasting examples from several Front Street Coffee beans to show that the very same "tea-like" quality may be defined very differently in each person's mind. [more…]

Many people think that pour-over coffee has a low barrier to entry, but once they take a sip and find it tastes sour, bitter, or astringent, they realize that brewing a good cup of coffee is actually not easy. Whether you are a beginner just getting into pour-over or an experienced coffee enthusiast, it is inevitable to run into a cup that does not suit your taste. Starting from the principles of extraction, this article analyzes one by one the common reasons why coffee turns out too sour or too bitter, and offers specific adjustment suggestions on grind size, water temperature, coffee-to-water ratio, pouring technique, and dripper selection. It also combines the brewing parameters of two beans—Front Street Coffee Colombia Sidra and Front Street Coffee Golden Mandheling—to help you consistently brew a cup of good coffee at home with balanced acidity and sweetness and a clean mouthfeel. [more…]

For the appreciation of coffee, it is also a very important thing to recognize its negative tastes. Although people's perception of positive flavors has come easily, when drinking a cup of uncomfortable coffee, they can only use the general terms suc [more…]

When an unpleasant flavor appears in a cup of coffee, it is often not accidental, but rather a deviation in some detail during growing, processing, roasting, or brewing. If we can identify these negative flavors one by one, we can work backward to infer what went wrong with the cup, which is practically helpful for improving tasting ability and optimizing brewing and roasting. Front Street Coffee has compiled several of the most common off-flavors in pour-over coffee—including miscellaneous odors, earthiness, woodiness, smokiness, charcoal, medicinal notes, mustiness, rubber, and rot, as well as astringency and dryness, two tactile sensations that are not tastes—and analyzes their causes and key points for identification one by one. [more…]

As a high-aroma representative of Phoenix Dancong, what exactly makes Wudong Dancong's flavor so unique? Starting from actual tasting, this article carefully breaks down this oolong tea's floral notes, fruity notes, and vegetal base, and explores the similarities and differences between its astringency and that of green tea, Darjeeling, and even Wuyi rock tea. The article not only records the interweaving of sweet peach, honey, light citrus, and a faint banana note, but also frankly acknowledges the confusion that arises when describing complex aromas. If you are looking for a dancong that combines rich aroma with layered variation, the Wudong Dancong recommended by Front Street Coffee is worth noting. Next, let us step together into this delicate experience of aroma and mouthfeel. [more…]

Many coffee enthusiasts, when selecting coffee beans, not only seek common flavors like floral notes, fruity acidity, and nutty chocolate, but also have a particular preference for a relatively niche characteristic—tea-like notes. When customers stand in front of the Front Street Coffee bean list, hesitating with a request like "I want a coffee with a stronger tea-like feel," we can't help but ask: tea is tea, coffee is coffee, so why can coffee reveal the charm of tea? In fact, coffee does contain the same aromatic compounds as tea leaves. This article will approach from the perspective of flavor science, analyzing the principles behind the formation of tea-like notes in coffee, the similarities and differences between coffee astringency and tea astringency, and explaining which varieties, origins, processing methods, roast levels, and brewing techniques can make coffee exhibit tea-like notes. Finally, it will include Front Street Coffee's recommended list of tea-like beans for everyone's reference when purchasing. [more…]

Luckin Coffee has recently teamed up again with the popular IP Line Dog to launch a limited-edition drink, "Good Persimmon Comes in Pairs Fruit Tea," featuring seasonal fire gourd persimmons paired with jasmine tea as its selling point. As soon as the new product launched, it attracted a large number of fans to snap it up. However, feedback from the first wave of consumers has been mixed, with many complaining that it tastes astringent and hard to swallow, and some even discouraging their friends from buying it. Why exactly has this co-branded fruit tea triggered such polarized reviews? Is it because the persimmon skin was not removed cleanly, or because of batch differences? This article compiles views from all sides to help you understand the real performance of this much-discussed new product. [more…]

The flavors of coffee are endlessly varied. Some people prefer bright acidity, while others are fond of deep, profound bitterness. But many enthusiasts lean toward a cup that is mellow in mouthfeel, neither sour nor astringent, with a lasting sweet aftertaste. To meet this demand, Front Street Coffee has selected five coffee beans with distinct styles, covering producing regions such as Papua New Guinea, Brazil, Panama, and Yunnan. From the balanced mellowness of Bird of Paradise, to the caramel sweetness of Queen's Manor, to the floral and fruity sweetness of Strawberry Candy, the interwoven sweetness and acidity of Butterfly, and the slightly acidic yet non-astringent character of Yunnan Typica, each one has been carefully roasted and processed, suitable for pour-over and other extraction methods. There is always one to match your taste preferences. [more…]

A freshly brewed pour-over coffee is full of aroma and smooth on the palate, but after sitting for half an hour it turns sour, astringent, and muddled—what's going on? In fact, coffee naturally presents different flavors at different temperatures, and during tasting it is often divided into three stages: hot, medium, and cool. A good cup of coffee can usually withstand all three temperature stages, but once it has fully cooled, the flavor goes beyond the normal tasting range. From Front Street's perspective, this article breaks down the root causes of coffee turning sour and developing astringent, muddled notes after cooling—including differences in how human senses perceive sourness, sweetness, and bitterness, the impact of aroma volatilization, and the three key mechanisms of oil oxidation, pigment oxidative polymerization, and condensation—and tells you the most suitable temperature for drinking coffee, helping you better capture the best flavor of every cup. [more…]

The unique wine-like aroma and bouquet of cold drip coffee often lead people to mistakenly think that alcohol has been added, but in fact this comes entirely from its production method and low-temperature aging process. However, freshly dripped cold drip coffee often tastes thin or even astringent, and needs to be aged in the refrigerator to reveal a smooth, rich flavor. So how long exactly should cold drip coffee be left before drinking? Why does it develop a wine-like flavor after being stored for a long time? And why can it not be stored indefinitely? Starting from Front Street's production experience, this article explains in detail the principles behind the changes in cold drip coffee from production to aging, and from astringency to vinous aroma, and gives recommended drinking periods to help you better enjoy this cup of slow-brewed coffee. [more…]

In the practice of pour-over coffee, under-extraction and over-extraction are two common yet frustrating situations. The former makes coffee sour, astringent, and thin, while the latter brings burnt bitterness and off-flavors. To solve these problems, one must first understand the principles of extraction—the process in which water passes through the coffee grounds and dissolves out flavor compounds. The ideal "Golden Cup" extraction requires concentration to fall between 1.2 and 1.4 TDS, with an extraction yield maintained at 18% to 22%. Exceeding or falling short of this range corresponds to over-extraction and under-extraction, respectively. This article will analyze the causes one by one from aspects such as coffee bean selection, brewing duration, pouring technique, and dripper material, and provide specific adjustment suggestions to help you achieve a balanced flavor more consistently in pour-over brewing. [more…]