Coffee has become an indispensable daily beverage for many office workers, with some even drinking several cups a day to stay alert. However, a recent news story has drawn widespread attention: a 30-year-old woman in Changsha, Hunan Province, who drank up to 5 cups of coffee a day, was diagnosed with osteoporosis and suffered a collarbone fracture from a minor fall. This raises the question of whether caffeine really causes calcium loss and osteoporosis. This article will review the incident, expert opinions, and online discussions, and, drawing on scientific research, explore the relationship between coffee and bone health to help coffee lovers take a more rational view of their daily drinking habits. [more…]

Channeling is often thought to be related only to espresso, but in reality, pour-over extraction can also exhibit this phenomenon. When hot water bypasses the coffee bed and flows directly away through the gap between the filter paper and the dripper, it causes uneven extraction. Drippers with flow-control ribs, such as the V60 and Origami, are more prone to this kind of problem. Channeling manifests differently depending on its severity: in mild cases, hot water flows over the coffee bed and escapes through gaps at the top; in severe cases, the coffee wall is breached, forming obvious fractures, resulting in weak, astringent, and muddy coffee. Fortunately, by adjusting the pouring method—for example, reducing large circular pours and lowering the pouring height—the occurrence of channeling can be effectively reduced. [more…]

Grind size is the most difficult part of pour-over parameters to master. Front Street Coffee uses an 80% pass rate through a No. 20 sieve as a beginner-friendly calibration baseline, but different grinders vary enormously in performance, and the same sieve pass rate can produce drastically different flavor outcomes. This article centers on grind calibration: it first explains the limitations of the sieve method and the particle size distribution characteristics of uniform grinders such as the EK43s, then offers remedies for poor-quality grinders, including hand grinder RPM control, the pull-back technique for staged grinding, and the direction for adjustment when too many fines cause off-flavors. Finally, it discusses the criteria for deciding whether sieving is necessary and the practical technique of a single-pour flush to wash away fines, helping you find the grind parameters that suit you. [more…]

The alluring flavor of coffee depends to a great extent on the physical and chemical changes that occur during roasting. From bean drop through dehydration, first crack, and second crack, every temperature node and duration shapes what ultimately ends up in the cup. In this article, Front Street Coffee will systematically walk through the temperature progression of each stage of coffee bean roasting, and, using a natural-process Yirgacheffe as an example, compare the specific flavor differences in cupping among light, medium, and medium-dark roasts, while also introducing the Agtron color value as a scientific criterion to help readers more accurately understand the correspondence between roast level and flavor. In addition, the article compiles representative beans from Front Street's lineup at different roast levels, making it easy for coffee lovers to follow the guide and find the cup that suits their taste. [more…]

The shape of the coffee bed after a pour-over often reveals whether the pouring technique was appropriate. Some beginners find that after brewing, the coffee wall breaks into two sections, with a thin ring of coffee grounds in the middle dotted with small bubbles, some grounds sinking to the bottom, and the coffee tasting less than ideal. This usually happens because the water flow was too forceful during the final pour, breaking through the coffee wall built up earlier, so hot water runs straight down along the filter paper's ribs, creating channeling and causing uneven extraction. In addition, too wide a pouring circle can also let the water level rise above the coffee wall, leading to under-extraction and bitterness. This article will analyze the causes of these two types of coffee beds and, drawing on Front Street Coffee's usual three-stage method, explain how to master the basics of flow control by managing pouring height and circle size, so that the coffee grounds release their flavors evenly. [more…]

When making espresso, hot water does not always pass evenly through the coffee puck—when the flow breaks through along paths of least resistance, the so-called "channeling" occurs. This phenomenon causes some coffee grounds to be over-extracted, releasing off-flavors, while other areas are under-extracted, ultimately throwing the strength and flavor of the entire cup out of balance. Channeling is especially prone to occur in espresso extraction, because the extreme conditions of high temperature and high pressure demand extremely high uniformity in the coffee bed. Although we cannot directly observe the state of the water flow during extraction, the holes on the surface of the puck and the spatter during extraction can both provide clues for diagnosis. This article will systematically explain the causes of channeling, how to identify it, and share Front Street Coffee's practical advice on optimizing distribution. [more…]

If you have coffee beans and hot water on hand but lack a grinder, what other methods can we use to turn the beans into grounds? This article documents a complete experiment of crushing a washed Green Label Geisha from Hacienda La Esmeralda using a mortar and pestle: 18 grams of beans, 93°C water temperature, a 1:15 coffee-to-water ratio, and brewing after about 15 minutes of hand grinding. The article describes in detail the grind size, pouring technique, and final flavor performance, and analyzes the problems of fine-powder clogging and uneven extraction caused by hand crushing, offering a genuine reference for coffee enthusiasts who lack professional equipment. [more…]

After pour-over brewing is finished, the coffee bed in the dripper often takes on different shapes—some people can produce a beautiful, even deep pit, while others end up with a flat bed or even a muddy crater. What exactly are these coffee bed shapes telling us? In fact, the appearance of the coffee bed mainly reflects information about the pouring method and the coffee grounds themselves, and has no direct correlation with whether the coffee tastes good. Front Street will start with six common coffee bed states, interpreting one by one the causes and meanings of the deep pit, the offset pit, the flat bed with a grounds wall, the flat bed without a grounds wall, the fractured bed, and the muddy pit, to help you better judge whether your pouring is appropriate in daily brewing and make timely adjustments. [more…]

In the three-pour method for pour-over coffee, the timing of the third pour is often overlooked—should you wait for the coffee liquid to completely drain before pouring, or should you top up promptly once the water level drops by half? Front Street Coffee conducted two sets of comparative experiments, using Costa Rica Strawberry Candy and washed Yirgacheffe beans respectively, to analyze in depth the practical differences between the two pouring methods from the dimensions of aroma, flavor, extraction time, and coffee bed state. The experiments revealed how the timing of the pour affects the temperature of the coffee bed, fine migration, and the final flavor performance, while also explaining why beans of different hardness show completely different results when faced with waiting for the liquid to drain. This article will present the full experimental process and conclusions to help coffee enthusiasts understand the core logic of judging when to pour in the three-pour brewing method, and provide Front Street's practical recommendations. [more…]

Water temperature, grind size, and coffee-to-water ratio are the three key variables that determine coffee extraction. Among them, grind size directly affects the particle size and uniformity of coffee grounds, which in turn influences how efficiently water passes through the coffee bed to extract flavor compounds. The finer the grind, the more tightly packed the coffee bed, the more resistance to water flow, and the longer the extraction time, so strength and extraction yield climb, producing a strong but easily bitter cup; the coarser the grind, the larger the gaps in the coffee bed, the smoother the water flow, and the lower the extraction yield, resulting in a weak, light-bodied coffee. This article uses grind size as the only variable, brewing three groups of coffee—fine, medium, and coarse—with Honduras Lychee Orchid beans, verifying grind size's effect on flavor through strength and extraction yield data, and providing Front Street Coffee's recommended hand-brew grind baseline, while also explaining the differences in characteristics among conical, flat, and ghost-tooth burrs. [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…]

In the grinding stage of pour-over coffee, the production of fines is almost unavoidable. These tiny particles, with a diameter of less than 0.1mm and a texture close to flour, are far off from the target particle size of 0.6~0.8mm. The source of fines is related both to the brittleness of the coffee beans themselves and directly affected by the quality of the grinder. For coffee enthusiasts, understanding the dual nature of fines—they can both improve extraction efficiency and enrich complexity, and may also bring bitterness and clogging—is the key to brewing the ideal flavor. This article will analyze the causes of fines, the differences between coarse and fine particles, and strategies for dealing with them during pour-over brewing, and provide reference in combination with the practical experience of Front Street Coffee. [more…]

Many coffee enthusiasts, after tasting an outstanding pour-over in a café, will buy the same roasted beans to try to replicate it at home, only to find the results often disappointing—either too sour or too bitter, too strong or too weak, sometimes even astringent, with off-flavors or a burnt taste. The reasons behind this are no mystery; they mainly involve consistency across batches of coffee beans, as well as differences in key parameters such as water quality, grind size, water temperature, coffee-to-water ratio, and brewing technique. Based on Front Street Coffee's brewing experience, this article breaks down these variables one by one to help you pinpoint the problem and brew coffee at home that is closer to café quality. [more…]

Peru, a South American coffee-producing country, has recently been hit by a series of natural disasters and environmental crises. The Sabancaya volcano in the south has entered an orange alert level, and ash from frequent eruptions is severely affecting nearby farms and pastures; meanwhile, the provinces of Huancavelica and Cusco have been declared in a state of environmental emergency due to heavy metal mercury contamination. Both regions have coffee cultivation, and mercury contamination not only inhibits crop growth and reduces agricultural product quality, but may also trigger labor shortages. The Peruvian government has already launched response measures, but concerns within the industry about coffee production and quality are rising. [more…]

Luckin Coffee's Geisha series sold out quickly upon launch, once again making this specialty coffee bean from Ethiopia a focal point. What exactly is the charm of Geisha coffee beans? Why are they named in the "Geisha X.0" format? And why does the price of small-batch Geisha remain so high? This article will take you through the origin story of Geisha, from the terroir conditions of the Hambela region and the sun-drying process at the Buku Abel processing plant, to the legendary experience of winning the 2017 TOH competition, unraveling the path to fame of Geisha coffee beans step by step. At the same time, we will also analyze the bean appearance characteristics of the new Geisha 6.0 harvest, its cupping flavor performance, and share Front Street Coffee's roasting and brewing recommendations for this batch of beans. [more…]

Wet Hulling is a unique green coffee processing method distinctive to Indonesia, known locally as Giling Basah. In this process, the parchment layer is removed by mechanical friction while the green beans still have a high moisture content, after which they are dried directly in the open, creating the signature full body and herbal, woody, and spicy notes of Mandheling coffee. Both Front Street Golden Mandheling and Front Street Lintong Mandheling are processed using this method. This article provides a complete overview of the wet hulling workflow and the origins of its flavor profile, along with brewing recommendations from Front Street Coffee's roasters and baristas for medium-dark roasted Mandheling, including grind size, water temperature, and a three-stage pouring technique. [more…]

On the same grinder at the same setting, why does switching to a different coffee bean produce noticeably different grind sizes? This actually comes down to two core physical properties of coffee beans—density and brittleness. Density is determined by growing altitude: the higher the altitude and the slower the growth, the harder the bean and the fuller the flavor. Brittleness, on the other hand, is directly tied to roast level: the darker the roast and the more moisture is driven off, the looser the structure and the easier the bean is to crush. Starting from actual experiments at Front Street, this article uses a comparison of the sieve-passing rates of dark-roasted Mandheling and light-roasted Yirgacheffe to explain why grind consistency breaks down, and how that leads to clogged filter paper and over-extraction problems. [more…]

On October 28, a distressing scene unfolded in a cat café in Wuxi, Jiangsu: a father, because a cat had startled his child, actually kicked the cat down the stairs. After the surveillance footage was exposed, netizens were furious and offered the shop owner advice on how to pursue accountability. However, because the owner had not called the police in time and feared retaliation afterward, he ultimately chose not to pursue the matter further. This incident once again sparked discussion about whether cat cafés should admit children, and also reflected the real-world dilemma of animal protection and the safeguarding of merchants' rights. [more…]

Among the many supplementary techniques for making coffee, RDT (Ross Droplet Technique) is a method of reducing static electricity and clumping by spraying water onto coffee beans before grinding. Its principle is not complicated: during grinding, coffee beans generate static electricity due to friction and uneven charge distribution, causing fine particles to stick together into clumps, which in turn lowers the extraction yield and induces channeling. RDT can effectively alleviate this problem, but it also has obvious shortcomings—it is only suitable for single dosing, the water amount is difficult to control, and long-term use may damage the burrs. In this article, Front Street Coffee breaks down the ins and outs of RDT, its actual effects, and its operational limitations in detail, and offers a more reliable alternative. [more…]

Coffee is a daily essential for many people, and opinions vary widely on its effects on the body. Dietitian Li Xingyu takes a scientific approach to break down five common questions one by one: Is black coffee really beneficial? Which groups of people need to limit their intake? What is the safe daily upper limit? Does adding milk to hot coffee affect health? Do dark-roasted coffee beans increase cancer risk? This article combines research data with professional advice to help you build proper coffee-drinking habits, while also recommending quality options from Front Street Coffee, so you can enjoy coffee with peace of mind. [more…]