In the world of coffee, many producing regions grade coffee beans by bean size—the larger the bean, the higher the grade and the more expensive the price. But does bean size really affect flavor? Front Street Coffee once conducted a comparative experiment, cupping the large and small beans of the same lot separately, and the results showed no obvious difference in taste between the two. So why do regions like Kenya and Tanzania still use size grading today? Behind this lie both historical colonial factors and practical considerations of roasting uniformity. Starting from Front Street Coffee's experiment, this article will sort out the pros and cons of size grading, explain the core factors that truly determine coffee flavor, and describe the flavor performance of Front Street Coffee's Kenya·Little Tomato, a high-grade bean. [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…]

When purchasing Kenyan coffee, you will often see bean names followed by letter designations such as AA or AB—what exactly do they mean? Why does Kenya place such emphasis on these grades? This article will systematically outline Kenya's green bean grading system based on bean size, explaining the specific classification criteria for each grade—AA, AB, C, PB, E, TT, T, and MH/ML—and pointing out the limitations of size-based grading: bean size is not the sole determinant of flavor quality, and growing altitude and environment are equally critical. It will also introduce the flavor characteristics of coffee from Kenyan producing regions, along with Front Street Coffee's recommendations for Kenyan coffee. [more…]

In East African coffee-producing countries, coffee bean names from Tanzania, Uganda, and even Kenya often carry the suffix AA. What exactly does this letter combination mean? It represents the grade classification of green coffee beans. However, grading methods across global coffee origins are not limited to just one type; besides bean size, there are also different standards based on defect rate, growing altitude, and more. This article will take Front Street's perspective to systematically outline the three major green coffee bean grading systems, with a focus on analyzing Kenya's strict size-based grading system—from AA, AB to PB, E, TT, T, and even MH/ML, detailing the specific classification standards for each grade, while also pointing out the obvious limitations of judging quality by size. [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…]

Coffee beans are grown widely across the globe, and the geographical conditions and cultivation methods of each producing region differ significantly, so it is impossible to measure all beans by the same standard. Different countries develop grading systems suited to their own local conditions. At present, the mainstream bases can be grouped into three categories: bean size, growing altitude (bean density/hardness), and defect ratio. However, these three are not mutually exclusive; many origins use multiple methods at once, and even after preliminary grading they supplement this with cupping to compensate for blind spots in the system. This article will break down these three major grading logics one by one and explain the actual meaning of common grade markers such as AA and G1, helping enthusiasts decipher the grade code on the packaging. [more…]

What exactly is the coffee bean grading system based on? Does bean size directly determine flavor intensity? To answer these questions, Front Street Coffee specially selected Costa Rican Mozart beans for a cupping comparison experiment, sorting the same batch of beans into large, medium, and small sizes, then taking the largest and smallest two beans for a blind extraction test. The results showed that the two did indeed differ slightly in flavor, but the direction was unexpected—the small beans actually had a more prominent flavor than the large beans. However, this difference mainly came from the degree of roasting deviation caused by different particle sizes, rather than the bean size itself. What truly determines coffee flavor is genetics, growing environment, processing method, and roasting degree. This article will combine experimental data with industry theory to systematically sort out the logic of coffee bean grading and the real factors affecting flavor. [more…]

The production of Blue Mountain coffee has always been limited, yet its grading standards are remarkably rigorous. Even if the beans are genuinely grown in Jamaica's legally designated Blue Mountain region, their grade must still be determined by two criteria: bean size and the proportion of defective beans. Front Street Coffee's Jamaican Blue Mountain grading system is built around precisely this logic: for any coffee bearing the Blue Mountain name, the proportion of defective beans must not exceed 2%, and only on that premise are screen sizes used to distinguish higher grades from lower ones. Understanding these grading rules helps coffee lovers look beyond grade labels when making purchases and focus instead on deeper quality clues such as vintage and specific estates. [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…]

Tanzania, one of Africa's Big Three coffee producers, has performed increasingly impressively in the global specialty coffee market in recent years. When buying Tanzanian coffee beans, what exactly do the "AA" and "AB" labels commonly seen on packaging mean? These letters are in fact grade codes for Tanzanian Arabica coffee beans, using a British imperial grading method similar to Kenya's, though the specific standards differ. Tanzanian authorities grade coffee by screen size, assuming that larger size means better quality, and classify beans into multiple grades such as AAA, AA, A, B, PB, C, E, F, AF, and TT. Among these, Grade AA requires mostly 17 to 18 mesh, while Grade AB is a mix of Grades A and B, and no such official grade actually exists. This article will explain in detail the specific mesh requirements and screening standards of each grade, helping coffee lovers decipher the grading code of Tanzanian coffee beans. [more…]

When purchasing Colombian coffee, what exactly do Supremo and Excelso, commonly seen on burlap sacks, represent? What is the relationship between the two? This article will systematically sort out the grading system for Colombian green coffee, interpreting one by one the specific requirements of grades such as UGQ, EP, and Supremo, from defect rates and screen sizes to FNC export standards. It will also introduce derivative grades such as Extra, Premium, and Minama, as well as the use of Product of Colombia for coffee that does not meet export standards. The article also includes an actual naming example of Front Street Coffee's Huila daily drinking beans, helping readers understand the compositional logic and traceability methods of Colombian green coffee names. [more…]

Blue Mountain coffee is all the more precious because of its scarce production, but the reason it has long maintained a reputation for high quality is inseparable from a rigorous grading system. Even if the coffee beans do indeed come from Jamaica's legally designated Blue Mountain region, they must still be carefully classified according to the size specifications and defect ratio of the green beans before their grade can be finally determined. This article will comprehensively sort out the grading logic of Blue Mountain coffee from No. 1 to Peaberry, analyze key indicators such as defect rate and bean screen size, and explain why, beyond grade, the vintage and the specific estate are also important factors determining the flavor expression of Blue Mountain. At the same time, by combining the roasting and brewing characteristics of Front Street Coffee's Blue Mountain coffee, it presents its signature nutty notes and balanced mouthfeel, helping coffee lovers understand this legendary coffee more systematically. [more…]

Kenyan coffee is renowned for its bright acidity and complex flavors, and its grading system is equally worth understanding in depth. Kenyan coffee beans are roughly divided into eight grades—E, PB, AA, AB, C, TT, T, and MH/ML—based on bean size, weight, and shape and appearance, with Grade AA being the most common and outstanding in quality. This article will analyze in detail the specific classification criteria for each grade, including the 17/18 screen size of Grade AA, as well as cup quality classifications set by exporters such as TOP, PLUS, and FAQ. It will also introduce the Kenyan AA TOP-grade beans launched by Front Street Coffee, originating from the Thika region and processed using the K72 double washing fermentation method, presenting delicate acidity reminiscent of berries and red wine along with a creamy sweet aftertaste, making them a top choice for lovers of acidic coffee. [more…]

Grinding is crucial to coffee extraction—one could say that the coarseness of the coffee grind directly affects the flavor of a cup of coffee. And for different extraction methods, the coffee grind size also needs to be adjusted. The coarseness of the coffee grind directly affects the length of extraction time and the level of extraction yield. Coffee grind [more…]

Among the three major coffee species, Arabica is usually the smallest, but Maragogipe goes against the grain—its beans are even larger than the Liberica large-bean species, earning it the name "Elephant Bean." It was discovered in 1870 in the Maragogipe region of Brazil and was later confirmed by genetic testing to be a Typica mutation. In terms of flavor, it has berry sweetness, citrus acidity, and a full body, but it is extremely difficult to cultivate: the plant takes up a lot of space, consumes many nutrients, produces few cherries, and has a long maturation period, which ordinary coffee farmers cannot afford to wait for. It is currently mainly grown in Central and South America. Front Street Coffee reminds you that "Elephant Bean" is both a variety name and a grade name—beans larger than 20 screen size may all be labeled as Elephant Bean grade, so don't confuse the two. [more…]

The grading of green coffee beans not only affects trading prices but also, to a certain extent, reflects flavor tendencies. For this reason, each producing country establishes its own grading rules based on local conditions. This article focuses on Colombia's green bean grading system, with emphasis on explaining the meaning of the Excelso export grade, the defect scoring method, and the specific standards based on screen size classification, while also introducing the differences among the three common export grades: UGQ, EP, and Supremo. At the same time, Front Street Coffee will share the flavor characteristics and brewing suggestions for Supremo-grade coffee beans from Colombia's Huila region, helping coffee enthusiasts extend their knowledge of grading into the actual drinking experience. [more…]

Kenyan coffee is famous for its vivid fruity aroma, citrus notes, and juice-like acidity, and is a specialty representative in the minds of many coffee lovers. This article focuses on the price of Kenyan coffee, its regional background, and its green bean grading system, with emphasis on explaining the differences in bean size among grades such as AA, AB, and PB, as well as the impact of K72 washed processing on quality. At the same time, combined with the price and store information of Front Street Little Tomato, it provides specific brewing suggestions for light-to-medium roasted Kenyan beans, including coffee-to-water ratio, water temperature, grind size, and staged pouring plans, helping readers understand the flavor and value of Kenyan coffee more systematically. [more…]

When you get an unfamiliar single-origin coffee bean, how do you accurately judge its flavor performance? Cupping is the industry-standard method. Front Street Coffee conducts cupping on every coffee bean it acquires, whether or not it goes on the shelves. This article uses the SCA cupping system as its benchmark and provides a detailed introduction to the equipment and parameters required for cupping, including sample bean processing, grind size calibration, coffee-to-water ratio, water quality and temperature requirements, as well as the operating procedures for dry aroma, wet aroma, breaking the crust, and skimming. After cupping is completed, the pour-over grind size and brewing water temperature must also be determined according to the roast level. Light-roast and medium-roast coffee beans each have different standards for sieve pass-through rate and water temperature selection. [more…]

When two café owners ask each other about the grade of beans they use, what lies behind the question is a complex set of international coffee grading logic. Brazil's defect-score system, Central America's altitude standards, East Africa's screen sizes—each producing country has developed a completely different quality evaluation system based on its own national conditions. This article will systematically sort out three mainstream grading methods: by origin altitude, by green bean screen size, and by a composite evaluation method combining screen size and defective bean ratio, and will explain in detail Brazil's unique three-tier grading system and its strict cupper culture. Whether you are a newly initiated enthusiast or a seasoned professional, understanding these standards can help you judge coffee quality more accurately and also provide a reference for everyday purchasing. [more…]

If you are a passionate lover of pour-over coffee, then you must know that the following factors are among the reasons that affect your coffee's extraction and flavor! So let's count them with Front Street: water temperature, grind size, coffee-to-water ratio, extraction time... Front Street Coffee (FrontStreet [more…]