The flavor of coffee, 60% comes from the raw beans, 30% comes from roasting, and 10% comes from brewing. It can be seen that there are many factors affecting the flavor of coffee. Then, as roasters, how to determine the degree of roasting of coffee b [more…]

In coffee roasting, how can we ensure that every batch of beans achieves consistent quality? In addition to relying on cupping to evaluate flavor, we also use the RoAmi roast degree analyzer to record the Agtron caramelization value of the coffee beans, and retain historical data for reference. The RoAmi is essentially a colorimeter, with SCAA's Agtron algorithm embedded inside, capable of calculating the roast value by reading the color data of the bean surface or ground surface. This article will introduce how to use this instrument, the meaning of the Agtron value, and how to calculate the Roast Delta value from the bean color value and ground color value, and interpret the guiding significance of this value for roasting rhythm and flavor performance. [more…]

The Agtron is a professional optical instrument used in the United States to determine coffee roast level. It analyzes the caramelization state of sugars inside coffee beans through infrared wavelength analysis, indicating roast depth with values from 100 to 25. This article provides a detailed introduction to the working principles of the Agtron M-Basic colorimeter, lists a complete correspondence table of numerical and color group values from extremely light roast to extremely dark roast, and explains that the flavor-recognizable range as determined by the SCAA Technical Standards Committee is actually 30 to 90. For coffee enthusiasts who wish to precisely control their roasting curves, understanding the relationship between Agtron values and roast level is an important foundation for grasping flavor direction. Front Street Coffee also often refers to this indicator in roasting practice to help present the best flavor expression of different beans. [more…]

Many friends who want to learn about coffee bean roasting are curious about one question: how to determine the roasting degree of coffee beans. Should a coffee bean be dark roasted or light roasted, and then how light should light be, and how dark should dark be? On what basis does Front Street Coffee determine the roasting of all these coffee beans it sells? [more…]

Judging the roast level of coffee beans by the naked eye alone, based on how light or dark the color appears, is clearly not rigorous enough. In the industry, a colorimeter is more commonly used to measure the degree of caramelization. This article will start with the measurement principle, explain the meaning of the Agtron value (color value), the difference between whole-bean color and ground-coffee color value, and how the RD value calculated from the difference between the two reflects roast uniformity. It will also explain how factors such as processing method affect the measurement results. Front Street Coffee will also present the commonly shared Agtron value roasting chart to help coffee enthusiasts more systematically understand the scientific basis behind roast assessment. [more…]

The roast level of coffee beans directly influences the flavor expression in the cup. From the extremely light roast with an Agtron color value of 95 to the Italian roast with a color value of 25, each stage has its corresponding drop time and flavor characteristics. This article systematically sorts out the flavor variation patterns of 8 roast levels, and combines the actual classification methods of commercially available coffee beans to help readers understand the taste directions of light roast, medium-light roast, medium roast, medium-dark roast, and dark roast. The article also uses Front Street Coffee representative beans such as Yirgacheffe, Mozart, Queen's Farm Brazil, and Golden Mandheling as examples to illustrate how different roast levels shape the balance of acidity, sweetness, and body. [more…]

Huakui coffee beans come from Hambela in the Guji region of Ethiopia, and are the exclusive name for the sun-dried coffee produced by the Buku Abel estate and processing station. This bean won the championship in the 2016/2017 Ethiopian coffee competition and second place in the African green bean competition, and is known for its rich floral and fruity aroma and fermented berry sweetness. This article will comprehensively interpret the flavor code of Huakui coffee beans from the dimensions of producing region background, processing method, green bean characteristics, roasting curve, and brewing analysis, and recommend the most suitable brewing equipment. It will also introduce the Huakui coffee beans roasted by Front Street Coffee, providing coffee lovers with a daily drinking option at high cost-effectiveness. [more…]

Want to roast coffee beans at home but don't know where to start? Front Street Coffee, drawing on the practical experience of baristas, introduces the key operating points of drum roasting and compiles SCAA's eight-level roast degree comparison chart—from light roast with an Agtron color value of 95 to Italian roast with a color value of 25, explaining one by one the timing of each stage's release from the roaster, appearance changes, and flavor performance. The article also compares the time differences between a professional roaster and drum roasting for the same Brazilian Cerrado Red Bourbon coffee beans, helping coffee enthusiasts understand how roast degree determines the acidity-bitterness direction of a cup of coffee. [more…]

Many coffee enthusiasts rely on the rule of thumb that acidity means light roast and bitterness means dark roast to judge the degree of roasting, but the industry has a more precise standard—the Agtron color value. From the perspective of Front Street Coffee, this article systematically sorts out a total of eight levels from light roast to Italian roast, and, combined with the timing of first crack and second crack for dropping the beans, explains the flavor direction and the changes in acidity and bitterness at each stage, and also explains the meaning of terms such as City Roast. At the same time, Front Street also shares how to use flavor descriptions to help consumers judge the roast level more intuitively, and gives brewing parameter suggestions corresponding to medium-light roast and medium-dark roast, so that you no longer feel troubled by technical terms. [more…]

During the bloom phase of pour-over coffee, whether the coffee bed puffs up into a large dome or stays relatively flat actually hides quite a bit of information. Although the degree of doming can't directly tell us whether the coffee tastes good, it can reflect the freshness of the coffee beans, the roast level, and the extraction efficiency during brewing. This time, Front Street Coffee will help everyone understand: why do some beans puff up like a balloon during the bloom while others stay flat and collapsed? What role does carbon dioxide play in this? Why do dark roasts and fresh beans puff up more? How do extraction parameters influence the degree of doming? Once you understand these things, you can read the bloom dome as a "bean status file" rather than mistakenly treating it as a standard for judging flavor quality. [more…]

60% of coffee's flavor comes from green beans, 30% from roasting, and 10% from brewing. It's clear that many factors influence coffee flavor. So, as a roaster, how do you decide the roast level of coffee beans? Today Front Street will talk about determining the roasting style. There are two points to keep in mind—cof [more…]

Since its debut in 2017, Huakui coffee beans have quickly gained popularity with their signature strawberry-cream flavor. This famous bean from Hambela in the Guji region of Ethiopia has now been iterated to version 8.0, but many enthusiasts report that Huakui's flavor in recent years seems not as good as before. This article will comprehensively sort out the origin of Huakui's name, the terroir of its producing region, and the sun-dried processing technique, and introduce one by one the various versions of Huakui that Front Street Coffee has acquired over the years, from G1 to 4.0, with roasting curves and brewing parameters, to take you through a comprehensive understanding of this coffee bean's past and present. [more…]

Since its introduction in 2017, Geisha coffee has quickly gained popularity with its bright strawberry and cream aroma, becoming a highly sought-after Ethiopian bean variety in coffee shops. From the original TOH champion batch to the current 8.0 version, many enthusiasts have noticed that the flavor of Geisha seems to change every year. This article will take you back to the origin of Geisha, Guji Hambela, to learn about the sun-drying process at the Buku Abel processing station, review the flavors and roasting curves of each version of Geisha that Front Street Coffee has sourced over the years, and analyze the causes of Geisha's aroma and the sources of its year-to-year differences. It will also share Front Street's V60 brewing parameters and techniques to help you better appreciate this classic coffee interwoven with passion fruit and berry notes. [more…]

When brewing pour-over coffee, a layer of foam often floats on the surface of the liquid in the dripper, sometimes rich and golden, sometimes thin and whitish. What exactly makes up this layer of foam? What can its color depth and quantity tell us about the brewing? From the perspective of Front Street, this article analyzes the sources of the foam's components, explains how large coffee particles affect the foam's color, and further reveals how the degree of roasting and the freshness of the coffee beans determine the richness of the foam, helping you adjust your pouring technique and judge the characteristics of the beans by observing the state of the foam. [more…]

The key to a delicious latte lies in the fusion state of milk and coffee and the temperature when it enters the mouth. This article will systematically explain the scientific principles of milk foaming, the factors affecting the fusion degree of milk foam and coffee, and reveal the differences in milk foam durability at different frothing temperatures through experimental data. At the same time, it provides cause analysis and solutions for common problems in daily operation, such as milk foam not fusing and milk foam floating up during latte art. The article also combines the practical experience of Front Street Coffee to explain why around 60°C is the optimal flavor temperature range for milk coffee, and how to judge whether the milk foam fusion degree is up to standard. [more…]

Coffee flavor is sixty percent determined by the green beans themselves, thirty percent by the roasting process, and only ten percent by brewing. For a roaster, choosing what roast level to use is often an expression of their understanding of the coffee beans, and there is no absolute right or wrong. This article, drawing on the practical experience of Front Street Coffee, systematically sorts out the criteria for determining roast level: color value standards and actual deviations, the reference significance of drop temperature, the critical range of only about ten degrees Celsius between first crack and second crack, and the two major decision-making logics of historical tradition and bean variety appearance. It uses Mandheling, Yirgacheffe, and Geisha as examples to explain the trade-offs and considerations behind dark roasting and light roasting, helping coffee enthusiasts gain a more comprehensive understanding of how roasting styles are formed. [more…]

Many people have heard of Blue Mountain coffee, but few are familiar with "Little Blue Mountain coffee." It is not Jamaican Blue Mountain, but rather coffee from Papua New Guinea. The country introduced Typica from Jamaica and shares a similar island climate and high-altitude environment, hence the name. This article provides a complete overview of the flavor code of Papua New Guinean coffee—from variety history, producing regions and estates, washed processing, and grading systems to roasting and brewing recommendations—and uses the Paradise Bird Estate coffee beans sourced by Front Street as an example to present its bright, clean cupping profile and pour-over performance. [more…]

Papua New Guinea coffee, because it was introduced from Jamaica Blue Mountain Typica and its growing environment is similar to Blue Mountain, is called "Little Blue Mountain" by many enthusiasts. Front Street Coffee has this year acquired a batch of Bird of Paradise coffee from Sigri Estate and conducted a complete set of tests from roasting and cupping to brewing. This article will walk you through Papua's coffee-growing model, its main producing regions, the history and ecological philosophy of Sigri Estate, and the origin of the name Bird of Paradise, and will also share this bean's washed-processing characteristics, roasting curve, and brewing parameters, helping you gain a more comprehensive understanding of the flavor profile of this rare producing region. [more…]

Yirgacheffe is one of Ethiopia's most iconic specialty coffee regions, and thanks to a millennium of cultivation heritage and meticulous washed processing, it presents a captivating flavor profile woven with lemon, floral notes, and honey. Front Street Coffee's Yirgacheffe, under a light roast, displays a fresh and bright citrus acidity along with a smooth fruity sweetness, with rich layers whether in its dry or wet aroma. This article will systematically outline the core characteristics of this bean from the perspectives of flavor and mouthfeel, roasting curve, varietal origins, and regional composition, helping coffee enthusiasts gain a more comprehensive understanding of its unique charm. [more…]

Papua New Guinea may be quite unfamiliar to most coffee enthusiasts, but a coffee bean called "Bird of Paradise" has brought this country into the spotlight of specialty coffee. In this article, Front Street Coffee will guide you through the coffee-growing background of Papua New Guinea, clarify the origin of the "Little Blue Mountain" title, and take a deep dive into the Bird of Paradise coffee from Sigri Estate—from the estate's history and ecological philosophy to green bean quality, then to Front Street Coffee's roasting curve and brewing parameters, and finally a complete flavor description of this bean. If you're interested in the flavor profile of island-grown Typica, why not join Front Street Coffee in savoring this washed gem from the Western Highlands Province. [more…]