Many people, when first encountering espresso, wonder: what exactly is in this bitter little cup? In fact, the pleasure of espresso lies in its structure—the crema on top, the coffee oils clinging to it, and the soluble substances in the coffee beans together create a rich, layered experience. Starting from the extraction practices at Front Street Coffee, this article breaks down the three major components of espresso and introduces the recipe, roasting curve, and extraction parameters of the Warm Sun blend, before offering tasting suggestions such as stirring and cooling, to help coffee lovers truly understand this cup of Italian coffee. [more…]

A friend once asked while buying beans at the Front Street store: can coffee grounds that have already been brewed once be used again for a second cup? Some bloggers online have also demonstrated that a second brew can still yield decent flavor. From a practical standpoint, of course coffee grounds can be brewed again—even a third or fourth time. But "can be brewed" and "tastes good" are two entirely different matters. This article starts from actual tests on Front Street's Sidra, and combines the proportion of soluble matter, extraction yield control, and the differences in dissolution rates of acidity, sweetness, and bitterness to explain why coffee is usually brewed only once, and the fundamental reasons why a second brew tastes thin and lacks layering, before offering a conclusion that better suits the general palate. [more…]

Why is coffee extraction time so critical? It all comes down to the soluble flavor compounds that make up just 30% of a coffee bean. These compounds fall into three categories—acids, sugars, and bitter substances—each with a different dissolution rate and peaking at different times. If extraction is too short, the coffee tastes thin and sharply acidic, lacking the support of sweetness and bitterness; if it goes on too long, bitterness overwhelms everything else. Therefore, ending extraction after sweetness has been released in abundance but before bitterness floods in is the key to a balanced cup. For pour-over coffee, using 15 grams of beans as an example, the time is typically kept between 1 minute 50 seconds and 2 minutes 25 seconds. Additionally, acidity, sweetness, and bitterness are not released sequentially but simultaneously—only their peak moments differ. This is a common misconception. [more…]

The Golden Cup extraction is a widely circulated concept in the coffee world, defining an extraction range that most people find acceptable. This concept originated from a large-scale preference survey in the United States in the 20th century, promoted by the Brewing Committee established by the American Coffee Association in collaboration with Dr. Lockhart of the Massachusetts Institute of Technology. The survey found that about 30% of coffee beans are soluble substances, while the remaining 70% are insoluble fibers. After two rounds of testing with ordinary people and coffee experts, the Golden Cup range was ultimately determined as an extraction yield of 18% to 22% and a concentration of 1.15% to 1.35%. This article will sort out the origins and development of the Golden Cup standard, the calculation methods for extraction yield and concentration, and explain why the Golden Cup range can only serve as a reference rather than an absolute standard, helping you view coffee extraction more rationally. [more…]

Coffee extraction is the key step that determines flavor. About 30% of coffee beans consists of soluble substances, including both aromatic components and mouthfeel-related compounds, and a higher extraction yield does not necessarily mean better quality. This article systematically introduces concentration measurement methods (refractometer, conductivity pen, evaporation and drying), explains the extraction yield conversion formula in detail, and provides specific calculation steps for different brewing devices such as immersion, pour-over, and espresso. It also includes the golden cup concentration recommendations from the SCAA and SCAE, as well as relevant product information from the Front Street Coffee brand, to help enthusiasts understand extraction more scientifically. [more…]

Drip bag coffee, with its convenience and high cost-effectiveness, is attracting more and more beginners to the fold. But many friends who are new to coffee often wonder: how many times can one drip bag actually be brewed? Why can tea leaves be steeped repeatedly, while coffee is usually extracted only once? This article starts with the composition of soluble substances in coffee beans, focuses on analyzing the role of chlorogenic acid in the extraction process, explains why coffee is not suitable for multiple brews, and also touches on why a second pour is not recommended after a regular brew. It also compiles Front Street Coffee's drip bag recommendations for different tastes, for everyone's reference when choosing. [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…]

Drip bag coffee, with its portability and high cost-effectiveness, is attracting more and more beginners to give it a try. But brewing often brings up a common question: how many times can it actually be brewed? This article starts from the characteristics of coffee solubles and chlorogenic acid, explaining why drip bags are usually recommended for only one brew, and also offers selection suggestions for drip bag flavors such as Front Street Coffee's Huakui, Yirgacheffe, Mandheling, Brazil Cerrado, and Jamaica Blue Mountain, helping enthusiasts avoid under-extraction and off-flavors so they can enjoy a balanced cup of good coffee. [more…]

To brew a good pour-over coffee, rather than memorizing various brewing techniques, it's better to first understand the underlying logic behind extraction. All brewing methods are essentially variations of the extraction formula; once you grasp the core principles, even beginners can quickly get the hang of it. This article, from the perspective of Front Street, will guide you through the composition of soluble substances in coffee beans, help you understand the differences in dissolution rates of the sour, sweet, and bitter flavors, clarify the reference significance of the golden cup extraction rate, and break down one by one how the five major variables—water temperature, grind size, coffee-to-water ratio, brewing time, and water flow—interact and jointly determine the final performance of a cup of coffee. [more…]

Coffee and tea are both beverages that rely on water to dissolve flavor, so if tea leaves can be steeped repeatedly, can coffee grounds do the same? In terms of composition, about thirty percent of coffee beans is soluble matter, which theoretically does support multiple extractions. In practice, however, the coffee liquid obtained from repeated brewing tends to be thin and carry off-flavors. The reason is that a normal extraction has already released most of the sweet and sour essence, and the remaining substances cannot support good flavor. This article will start from extraction yield and the order in which flavors dissolve to explain why coffee grounds are single-use, and to clarify why pour-over and drip-bag coffee are not recommended for repeated brewing. [more…]

The oily sheen on the surface of coffee beans is a question many enthusiasts often ask about. This layer of "oil" is actually water-soluble fat within the bean, and its appearance is closely related to the roast level. Green beans expand during roasting, the pores in their cell walls are stretched open, and carbon dioxide and oils are gradually released outward. Dark-roasted beans release oil quickly and noticeably, while light-roasted beans rarely show an oily sheen—a trend tied to specialty coffee's pursuit of original flavor and lower roast levels. Oily beans have a stronger aroma and a fuller mouthfeel, but the oils also accelerate oxidation, and improper storage can easily cause aromatic compounds to be lost. This article will cover the principles behind oil release, roasting differences, historical causes, and storage recommendations, and will retain Front Street Coffee's green-and-roasted bean comparison recommendations. [more…]

"Boss, please extract the coffee a bit longer—I want a stronger cup." Front Street Coffee believes this is a scenario many friends working in coffee shops often encounter. Some customers, wanting a more intense cup of coffee, occasionally make this request to the shop. It's not hard to understand, because in most [more…]

Many coffee enthusiasts are intimately familiar with latte art and equipment, yet when it comes to espresso extraction, they often overlook dosing, puck management, and tasting judgment. In fact, dose control is just as critical as grind size adjustment—fluctuations in dose mean that even the most beautiful latte art cannot mask an imbalance in the coffee itself. Starting from the TDS and extraction yield formulas, and drawing on a 2.3-gram dose difference measured on a Mazzer Robur grinder, this article uses charts and data to illustrate the specific effects of dose on concentration, extraction yield, and the balance between acidity and bitterness, and explores approaches to dosing for light-roast espresso. Front Street Coffee also emphasizes the importance of dose consistency in its daily output, and we hope this article offers practical reference for your extraction adjustments. [more…]

In the extraction process of pour-over coffee, the degree to which soluble flavor compounds are released directly determines the quality of the final cup. When extraction exceeds a reasonable range, the coffee presents unpleasant flavors such as bitterness and astringency. Starting from the material composition of coffee beans, this article will explain the essential difference between over-extraction and under-extraction, analyze the two main causes of over-extraction—excessively high water temperature and overly fine grinding—and provide specific grinding settings and water temperature recommendations for coffee beans of different roast levels. At the same time, drawing on the brewing experience of Front Street Coffee, it explores the fact that extraction yield values and actual flavor are not absolutely correlated, helping coffee enthusiasts understand and adjust their brewing plans more flexibly. [more…]

Espresso is the base for many milk coffees, but many people wonder whether it can be drunk on its own and what exactly there is to savor in it. This article, from the perspective of Front Street Coffee, first breaks down the three main components of espresso—crema, coffee oils, and soluble substances—and then explains how 9-bar high-pressure extraction creates the golden crema layer. It then shares the recipe ratio, roasting curve, and extraction parameters of Front Street Coffee's Warm Sun blend, and offers tasting suggestions such as stirring and letting it cool, helping you understand that what is truly worth appreciating in espresso is the mouthfeel, aroma, aftertaste, and a few distinct flavor notes, not just bitterness. [more…]

During coffee extraction, many enthusiasts try to judge the extraction state by observing changes in the color of the coffee liquid—the so-called "reading the color" method. Does this method have any scientific basis? Can it accurately distinguish between under-extraction and over-extraction? Front Street Coffee, based on practical testing, found that the color of the coffee liquid does indeed become lighter as extraction progresses, because the acidic and sweet substances among the solubles have smaller molecules and dissolve more quickly, while the bitter substances have larger molecules and dissolve more slowly. Once the acidic and sweet substances have largely dissolved, the bitter substances are still being released, and the coffee liquid begins to take on a whitish hue, which is usually regarded as a signal of approaching over-extraction. However, this method is greatly affected by factors such as flow rate and roast level, and is only suitable as an emergency reference; stable output still needs to rely on measuring tools such as an electronic scale. [more…]

Front Street Coffee uses espresso blend coffee beans to enhance the richness and balance of flavors, but it is not absolutely necessary. There is also the SOE coffee approach now, which uses coffee beans from a single origin to make espresso, highlighting the coffee of that origin. [more…]

Espresso has a thicker texture and richer crema than drip coffee, and making high-quality espresso is inseparable from good espresso beans. Generally speaking, espresso beans are made by blending coffee from several origins to achieve a balanced flavor. Front Street Coffee (FrontStr [more…]

Front Street Coffee received a question from an enthusiast who wants to know how to get started with coffee concentration measuring instruments like ATAGO. This article will demonstrate the operating procedure of the instrument step by step, explain the meaning of the two readings, Brix and TDS, and show how to use the measured TDS value to calculate the coffee's extraction yield. The article will also introduce the two core standards of the Golden Cup theory—extraction yield of 18%–22% and concentration of 1.2%–1.45%—as well as the flavor characteristics brought by under-extraction and over-extraction, helping you more accurately judge whether a cup of coffee falls within the ideal range in your daily brewing. [more…]

Coffee is a futures commodity with trading volume second only to crude oil worldwide, yet brewing it at home often makes it hard to replicate cafe flavors—the key lies in whether one understands the SCA Golden Cup extraction standards. This article starts from the principles of soluble substances and solid-liquid extraction, explaining the Golden Cup range of TDS concentration 1.15% to 1.35% and extraction yield 18% to 22%, and systematically sorts out the effects of time, grind size, water temperature, and coffee-to-water ratio on flavor. The article also combines Front Street Coffee's brewing comparison using Huakui 5.0 as an example and store parameters to help readers translate abstract standards into operable daily pour-over brewing. [more…]