Before green coffee beans reach our hands, they often go through many stages, during which defects are almost unavoidable. Some defects are obvious at the green bean stage, yet once roasted they may be cleverly concealed. The SCAA (Specialty Coffee Association of America) has established strict grading standards for specialty Arabica coffee, covering multiple dimensions such as defect types, moisture content, aroma, and bean size. This article will systematically sort out the SCAA's defect classification rules and scoring requirements, explain in detail the causes of various defective beans and their impact on cupping flavor, and help enthusiasts develop a keen eye for identifying specialty coffee. At the same time, the article retains relevant recommendations from the Front Street brand for readers' reference. [more…]

Defective beans are generally considered in the specialty coffee world to affect the flavor performance of a cup of coffee. If you have the habit of buying coffee beans and brewing at home, do you need to specifically pick out defective beans before brewing? In fact, green coffee beans undergo grading after processing, and most grading systems include a defect rate indicator. The number of defects in high-grade coffee beans has already been pressed to a very low level. From green bean grading, removal before roasting, to screening after roasting, with layer upon layer of checks, there is basically no need to worry about defective bean issues when buying roasted single-origin coffee beans. However, some coffee beans that look like defects are actually normal phenomena. Front Street Coffee has summarized several common types of situations that are easily misjudged, to help everyone distinguish them accurately. [more…]

Many coffee enthusiasts, when first encountering coffee beans, often misjudge defective beans based on unusual appearance. In reality, true defective beans are mainly concentrated at the green bean stage, and most have already been screened out at the producing region and roasting stages. Among the beans consumers buy day to day, those covered in wrinkles, with cracks, or on the lighter side in color are often not defects, but normal phenomena brought about by light roasting, high-altitude cultivation, or specific processing methods. This article systematically sorts out the classification standards for green coffee bean defects, distinguishes true defective beans from appearance traits that are easily misunderstood, and introduces Front Street Coffee's practice of double screening before and after roasting, helping readers build a more accurate basis for judging quality. [more…]

As an agricultural product, coffee beans vary significantly in quality, so a grading system is needed to standardize quality and provide reference for buyers. However, the geographical environments and cultivation models of global producing regions differ enormously, making it impossible to measure them with a unified standard; each region can only adapt to local conditions. Currently, mainstream grading methods fall into three major categories: screen size, altitude/hardness, and defect rate, and many countries combine them or even add cupping to compensate for shortcomings. This article will systematically sort out the logic and representative producing countries of these three grading methods, with a focus on analyzing how Kenya grades solely by bean size, and introduce the grading practices of Colombia, Ethiopia, Jamaica, Indonesia, Brazil, and other countries. Front Street Coffee will also share related brand product information to help coffee enthusiasts understand the meaning behind green bean grades. [more…]

Colombia's coffee grading system is more complex than that of most Central American producing countries. It is based not only on altitude, but also on a set of export standards built around defect rates and screen size. The Excelso grade adopted by the FNC is the highest export grade for Colombian green coffee. The burlap sacks are marked with "Excelso-Café de Colombia" and accompanied by a quality certificate. This article covers everything from the grading logic, screen size requirements, and defect deduction rules to the three most common export grades, and uses a washed Caturra from the Huila region as an example to explain green coffee traceability and cupping flavor performance, helping coffee enthusiasts understand the meaning behind Colombian green coffee labels. [more…]

For more specialty coffee knowledge, please follow our WeChat official account: Front Street Coffee (FrontStreet Coffee). Many friends, while drinking coffee at Front Street, ask our baristas, "What is Yirgacheffe G1 and Yirgacheffe G2?" "What is Kenya AA, AB?" What is Guate... [more…]

Many pour-over coffee enthusiasts often have doubts about the appearance of the beans after purchasing single-origin beans, and even mistake normal beans for defective ones. There are two main reasons for this misunderstanding: first, consumers who only come into contact with roasted beans rarely see truly defective beans; second, they treat coffee beans as products of an industrial assembly line, assuming they have a fixed standard appearance. In reality, most defective beans are already controlled at the green bean stage, and after roasting there is also manual sorting. This article will systematically sort out the definition of defective beans, the defect rate requirements in green bean grading, and focus on explaining several commonly misjudged situations such as peaberry, burst beans, uneven color, and shriveled wrinkled beans, to help readers view the appearance of coffee beans more rationally. [more…]

Coffee enthusiasts often ask in the shop exactly what the difference is between Ethiopia's G1 and G2, what Kenya AA actually means, and what Costa Rica's SHB grade signifies. These combinations of letters and numbers actually reflect how each producing country evaluates the quality of green coffee beans. Due to differences in history, trade, climate, and terrain, different origins have developed their own grading systems, with evaluation criteria covering multiple dimensions such as defect percentage, bean size, growing altitude, green bean density, and processing method. This article will systematically sort out the origins of coffee grading and introduce, one by one, the green bean grade standards of representative producing countries such as Ethiopia, Kenya, Colombia, Jamaica, Costa Rica, Panama, Guatemala, El Salvador, Honduras, and Brazil. [more…]

Colombia is a major producer of global Arabica coffee, and its green bean exports follow a grading system centered on defect rates and bean size. What exactly do the Supremo and Excelso labels commonly seen on the market represent? Starting from FNC's export standards, this article sorts out Excelso's mandatory requirements, the logic behind screen-size grading, and the specific tolerance rates for the three commonly used grades UGQ, EP, and Supremo, while also explaining the defect scoring rules behind the number string "12*60," helping coffee enthusiasts decipher the grading code in the names of Colombian green coffee beans. [more…]

When you buy a bag of coffee beans and open it only to find the colors uneven, many people's first reaction is that "the roast went wrong." But coffee beans, being an agricultural product, can never be uniform bean for bean. This article explains, from the perspectives of green bean grading, honey processing, and anaerobic fermentation, the reasons why light-roasted coffee beans vary in shade, while also clarifying the difference between white-eye beans and normal beans, and pointing out several appearance traits often mistaken for defective beans. At the end, it uses examples from Front Street Coffee's Sherry and Warm Sun blends to illustrate how the roast level affects bean surface color and flavor performance. [more…]

Those new to specialty coffee are often confused by labels such as G1 and AA on the packaging. These letters and numbers actually represent the grading systems for coffee beans from different origins. Some countries grade by bean size, others by the proportion of defective beans, and still others by growing altitude. Take Mandheling as an example: Indonesia uses the wet-hulling process and grades beans from G1 to G6 based on the number of defects in 300 grams of green coffee. Geisha coffee, by contrast, is famous for Hacienda La Esmeralda's red, green, and blue label system. This article will systematically sort through these grading systems while taking a deeper look at the core differences in flavor and mouthfeel between Mandheling and Geisha, helping coffee lovers understand the logic of quality evaluation in specialty coffee more clearly. [more…]

In coffee roasting, understanding green bean characteristics is the foundation for developing a roasting strategy. Starting from the Front Street Coffee roasting course, this article provides a detailed analysis of how the three key indicators of green beans—moisture content, density, and size—affect heat transfer and flavor development, and systematically introduces the causes and harms of common defective beans such as shell beans, insect-damaged beans, moldy beans, black beans, and white-eye beans. Mastering this knowledge helps with proper screening and adjustment before roasting, ensuring the final coffee flavor is clean and rich. [more…]

When selecting coffee beans, you'll often come across labels like Yirgacheffe G2 or Kenya AA. Behind these letters and numbers lies the logic each producing country uses to assess green bean quality. Due to differences in history, trade, climate, and terrain, grading criteria vary widely from country to country—some focus on defect rates, some measure bean size, and others test altitude or hardness—and they cannot be directly compared across origins. Front Street Coffee has compiled the grading systems of representative producing countries including Ethiopia, Kenya, Colombia, Jamaica, Costa Rica, Panama, Guatemala, El Salvador, Honduras, and Brazil to help you understand the ins and outs behind green bean grades. [more…]

Colombian coffee occupies an important place in the world of specialty coffee, and its green bean grading system is based primarily on defect rates and bean screen size. When buying Colombian coffee, what exactly do the words "Supremo" and "Excelso" commonly seen on burlap sacks mean? This article will systematically sort out the grading rules for Colombian green coffee beans from multiple angles, including export standards, defect scoring, and screen-size classification, and explain the specific differences among the three grades UGQ, EP, and Supremo. At the same time, the article will also introduce common Colombian coffee bean brands on the market, including product information recommended by Front Street Coffee, to help coffee lovers more clearly understand the grade and quality of the bag of beans in their hands. [more…]

Mandheling coffee is deeply favored by enthusiasts for its rich and full-bodied taste, but do you know the grading standards for Indonesian coffee beans? What exactly are the differences between PWN Golden Mandheling and regular G1 Mandheling? This article will provide a detailed introduction to the grading system for Indonesian green coffee beans, analyzing the grade standards from G1 to G6 based on defect rates, screen sizes, and other dimensions, and will delve into how PWN company creates its uniquely distinctive Golden Mandheling through strict screening processes. At the same time, Front Street Coffee will share brewing suggestions for Golden Mandheling to help you better savor this high-quality coffee with regional character. [more…]

The SCAA Coffee Flavor Wheel is a core tool for specialty coffee enthusiasts to identify flavors, yet many people are still unfamiliar with it. This article systematically breaks down the left-right structure of the flavor wheel: the right side, the normal flavor spectrum, reveals the three major aroma sources of fermentation, sugar browning, and dry distillation, while the left side, the negative flavor spectrum, corresponds to the defective flavors produced by improper green bean processing, storage, and roasting. It also explains in detail the deduction rules for different defects in SCAA cupping—serious defects deduct 4 points, minor defects deduct 2 points—and how roasting and organic matter loss, although not deducting defect points, can lower flavor performance. The article includes the latest high-definition Chinese-English flavor wheel images and retains Front Street Coffee's communication channels, making it suitable for readers who want to gain a deeper understanding of coffee sensory evaluation. [more…]

As an agricultural product, coffee beans vary significantly in quality, which is why grading systems have become an important means of standardizing quality and guiding green bean procurement. However, the grading criteria across global producing regions are not uniform—Central America mostly grades by altitude, Kenya by bean size, while Ethiopia uses defect rates to classify grades. Why does Ethiopia take this unique approach? What substantive differences actually exist between the G1 and G2 grades? This article, from the perspective of Front Street Coffee, sorts out the evolutionary logic of Ethiopia's grading system, and through a visual comparison of Yirgacheffe G1 and G2 green beans, roasting performance, and cupping evaluation, reveals one by one the true meaning behind grade labels, helping coffee enthusiasts view the issue of bean grades more rationally. [more…]

Ethiopia, as the genetic treasure trove of Arabica coffee, has a unique green bean grading system. Unlike Kenya, which grades by bean size, or Blue Mountain, which grades by altitude, Ethiopia primarily classifies grades based on defect rates and cupping scores. This article will systematically sort out the evolution of Ethiopia's old and new grading systems, provide an in-depth analysis of the specific standards for grades G1 through G9, and, using Yirgacheffe as an example, compare the actual differences between washed G1 and G2 in green bean appearance and flavor performance. It will also share Front Street Coffee's brewing parameters and tasting experience to help coffee enthusiasts fully understand the logic of Ethiopian coffee quality grading. [more…]

The grading systems for coffee beans vary widely depending on the origin—some are based on the number of defects, others on bean size, and still others on altitude. Understanding these grade labels is an important step in selecting high-quality coffee. This article will systematically outline the green bean grading rules of major global producing regions, covering common designations such as Ethiopia's G1-G9, Kenya's AA and PB, Colombia's Supremo, and Hawaii's Extra Fancy, and explain how cupping scores further distinguish specialty grade from commercial grade. Whether you are a beginner enthusiast or a professional seeking to advance, this grading guide can help you judge coffee quality more clearly. For more professional content, follow Coffee Workshop; for specialty coffee beans, add Front Street Coffee on WeChat at qjcoffeex. [more…]

Friends who frequently buy coffee beans have surely seen labels like Yirgacheffe G2 and Kenya AA. These letters and numbers actually represent the grade of green coffee beans. Since each coffee-producing country has established different grading systems, the evaluation criteria also vary in emphasis—factors such as bean size, proportion of defective beans, growing altitude, bean hardness, and cupping score can all serve as the basis for grading. In this article, Front Street Coffee will walk you through the green bean grading rules of representative producing countries including Ethiopia, Kenya, Tanzania, various Central and South American countries, Colombia, Brazil, and Jamaica, helping you understand the grade labels on packaging the next time you shop. [more…]