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…]

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…]

From light to dark roast, coffee beans may differ by only about 10°C in temperature, yet their flavors can be completely different. The degree of roasting not only affects the beans' color, size, density, and brittleness, but also reshapes aroma and taste through the Maillard reaction and caramelization. This article starts with roast classification, explains the SCAA color value standards and the flavor characteristics of light, medium, and dark roasts, and combines the specific performances of Front Street Yirgacheffe·Red Cherry and Front Street Warm Sun Blend to help readers understand how different roast levels affect the balance of acidity and bitterness, aroma complexity, and energizing effect. [more…]

Common labels on coffee bean packaging such as light roast, medium roast, and cinnamon roast often confuse beginners. The roast level directly determines the direction of coffee flavor, and historically different countries and regions have had their own schools of thought for defining roast levels, lacking a unified standard. The Specialty Coffee Association of America, together with Agtron, used infrared caramelization measurement values as the basis to divide roast levels from light to dark into eight grades, which has become an important industry reference. In this article, Front Street will systematically introduce the Agtron color values, drop times, and flavor characteristics of each roast level, and share how to judge the roast level through flavor descriptions, as well as the grinding degree and water temperature parameters that should be used for different roast levels. [more…]

Many coffee enthusiasts, upon receiving a bag of beans labeled as medium roast, often wonder: why does the color look like a dark roast? Sometimes a single bag even contains beans of two different colors—does that mean the roast is uneven? In fact, these phenomena are not necessarily quality control failures; they are very likely related to how the beans were processed. This article will explain how coffee beans gradually turn brown during roasting through the caramelization reaction, and clarify why honey processing and special processing methods can make the bean surface appear darker. It will also introduce how roasters use indicators such as color value to judge the degree of roast, helping readers understand the relationship between roasting and appearance more objectively, and avoid misjudging a bean's true roast level based on color alone. [more…]

For more specialty coffee knowledge, please follow: Front Street Coffee (Frontsteet Coffee). Some friends who have purchased Front Street Coffee (FrontStreet Coffee) beans may be a bit confused about why Front Street's coffee bean labels don't indicate the roast level. [more…]

The flavor profile of coffee beans is largely determined by the roast level. For coffee enthusiasts, mastering methods to distinguish light from dark roasts can both help in selecting suitable beans and allow for a more accurate understanding of the flavor descriptions on packaging. From the perspective of Front Street Coffee, this article outlines three practical ways to judge: first, by visually observing the bean surface color and wrinkle condition; second, by inferring the roast range from flavor descriptors; third, by referring to the SCAA's Agtron infrared caramelization measurement standard, which categorizes eight color values into four major groups. The article also includes Front Street product recommendations for each roast level, for everyday purchasing reference. [more…]

The color differences that coffee beans display after roasting are not arbitrary; the industry long ago established a scientific quantitative standard—the Agtron color value, also known as the caramelization analysis number. This set of values runs from 95 to 25, corresponding to eight levels from light roast to Italian roast: the higher the number, the lighter the color, and the lower the number, the darker it is. Each color value range has a clear drop time node and flavor characteristics: from light roasts dominated by bright acidity, it gradually transitions to dark roasts dominated by bitterness and smoky notes. Understanding these color values not only helps us recognize the correspondence between roast level and taste, but also helps us understand why very dark roasts are now hard to find under the specialty coffee trend. But color value is only a reference tool; in actual judgment, tasting perception is still needed, since factors such as processing method also affect the appearance of the beans. [more…]

The roast level of coffee beans directly influences the final flavor profile, yet standards vary from country to country, often leaving beginners confused. From the perspective of Front Street, this article systematically introduces the eight-level roasting standard developed by the SCAA in conjunction with Agtron, including the color values and drop times for Light, Cinnamon, Medium, Deep, City, Full City, French, and Italian roasts, and explains how to determine the roast level through flavor descriptions. At the same time, for coffee beans roasted at light-to-medium and medium-dark levels, Front Street shares specific grinding and water temperature recommendations to help everyone brew their ideal flavor more effectively. [more…]

When buying coffee beans, besides origin and processing method, roast level is often one of the elements we care about most, as it directly determines whether the cup's flavor leans sour, sweet, or bitter. The industry commonly uses the Agtron color value card to distinguish roast levels, but this standard is not universal—honey-processed and anaerobic beans often "deceive" the color value. Why doesn't Front Street Coffee label the roast level on its beans? Where does the sourness in coffee come from? This article will walk you through the principles and limitations of color value, and teach you to judge roast depth through flavor descriptions and drop time, so you no longer feel lost when selecting coffee. [more…]

The roast level of coffee beans directly affects the final flavor profile, but the labeling methods on the market are diverse, ranging from light roast to cinnamon roast, often leaving beginners confused. This article, from the perspective of Front Street, systematically sorts out the definition standards and flavor characteristics of coffee roast levels. Using the SCAA's Agtron color value system, it divides light to dark roasts into eight levels and explains the dropping timing and flavor performance of each stage one by one. At the same time, the article also shares how to infer the roast level from flavor descriptions, the bean selection logic for espresso, and the pour-over grind size and water temperature parameters corresponding to different roast levels, helping you accurately judge and brew a good cup of coffee even when labeling is lacking. [more…]

The roasting process of every coffee bean requires detailed recording of curve data, including the turning point, heat adjustments, temperature changes, and first crack time. These data are not only the basis for reproducing flavor, but also an important reference for roasters to understand the characteristics of the beans. This article will break down the key nodes in the roasting curve one by one—from the preheating drum temperature setting, the coordination of heat and airflow, to the turning point, yellowing point, Maillard reaction, caramelization reaction, and then to the determination of first crack and the calculation of the rate of rise—to help you build a clear logic for reading roasting curves. At the end, using [Front Street Jamaica Blue Mountain] as an example, it shows how to design the roasting rhythm according to the nature of the beans, so that acidity, body, and aroma reach a delicate balance. [more…]

For pour-over enthusiasts who prefer a rich, bold body and dislike pronounced acidity, the medium-dark roasted Mandheling series has always been a popular choice. As a representative of this series, Front Street Coffee PWN Golden Mandheling owes its flavor appeal largely to its roasting method. This article will start with the chemical principles of roasting, analyzing how caramelization and the Maillard reaction shape coffee flavor, explaining why a medium-dark roast can fully bring out the herbal, caramel, and pine notes of Golden Mandheling, and providing a specific roasting curve along with two brewing methods to help readers fully understand the flavor sources and extraction key points of this bean. [more…]

Grind particle size is one of the key variables that determines the direction of coffee flavor. Starting from the practices of Front Street Coffee, this article systematically reviews the influence of grind size on extraction efficiency in pour-over coffee, the grind standards suited to medium-light and medium-dark roasts respectively, and how to use a 0.85mm No. 20 sieve to test the pass-through rate. It also extends to the extremely fine grind requirements of espresso, explains the effect of the grinder burr spacing on extraction time, and provides the specific extraction parameters and flavor description of Front Street espresso. In addition, the article also explains the relationship between the choice of Moka pot coffee grounds coarseness and the oils it produces, helping coffee enthusiasts find a grind plan suitable for their own equipment at home. [more…]

For more specialty coffee knowledge, please follow: Front Street Coffee (Frontsteet Coffee) The roast level of coffee beans determines the direction of the coffee's flavor. Many coffee shops label the roast level on the coffee beans they sell, such as light roast, medium roast, cinnamon roast, etc., which makes it easy for beginners [more…]

We usually talk a lot about coffee bean brewing, but today Front Street Coffee will explain coffee bean roasting knowledge to everyone. We know that the process of coffee beans going from green beans to roasted beans is the roasting process, and this process includes light roast, medium roast, and dark roast. Exactly how should different coffee beans be roasted? At the same time, light roast, medium roast [more…]

Coffee roasting is the core step that determines the direction of flavor. The SCA (Specialty Coffee Association) color card divides roast levels into eight grades, each with corresponding color values and sensory characteristics from extremely light to extremely dark. This article focuses on this standard color card, explaining one by one the bean surface color, weight loss ratio, flavor tendency, and suitable applications of each roast level, while also organizing the causes and identification methods of common green bean defects. The article also includes Front Street Coffee's reference guidelines to help roasting enthusiasts match color card readings with actual practice, choose the right roasting curve, and make the cup they want. [more…]

Does the roasty aroma of coffee only come from dark roasting? Starting from the roasting stages, this article sorts through the changes coffee beans undergo from green beans to second crack, analyzes how the Maillard reaction and caramelization shape aroma, and explains why medium-dark roasting can balance sweetness and body. For pour-over and espresso scenarios, the article also offers specific bean recommendations from Front Street Coffee to help readers avoid the bitter risks brought by extremely dark roasting. Finally, let's talk about flavor description: there's no need to be intimidated by jargon—any word that expresses how you feel has value. [more…]

Many people, when they hear "dark roast coffee beans," immediately think of burnt bitterness, heavy smoky flavors, or even find them hard to drink. But is that really the case? A properly roasted dark roast bean can actually offer pleasant notes of cocoa, dark chocolate, caramel, and nuts, with low acidity and a full body, balanced between sweetness and bitterness. Drawing on Front Street Coffee's roasting experience, this article sorts out the relationship between the Maillard reaction and roast level, and recommends a variety of Front Street medium-dark and dark roast products for different taste preferences, including Queen's Estate, PWN Golden Mandheling, Classic Blend, Specialty Blend, Commercial Blend, and Dark Cocoa Base Blend, helping coffee lovers find the rich, full-bodied choice that suits them. [more…]

The roast level of coffee beans directly affects the final flavor expression, but how exactly are the boundaries between light, medium, and dark roasts defined? Different countries and regions once had their own standards, until the Specialty Coffee Association of America, together with the Agtron company, introduced a unified color value system, giving roast communication a common language. This article, starting from Front Street Coffee's roasting practice, systematically sorts out the Agtron color values, drop timing, and flavor trends of eight roasting stages. At the same time, Front Street Coffee will also share the specific roasting curves and brewing plans for Yirgacheffe Gedeb Cooperative coffee beans and PWN Golden Mandheling coffee beans, helping coffee enthusiasts more intuitively understand the relationship between roast level and acidity, as well as body. [more…]