Fines in pour-over coffee are always a double-edged sword: retaining them can bring complexity, but they can also easily cause clogging and over-extraction; discarding them entirely can improve consistency, but it makes the flavor seem flat. Front Street Coffee, combining its own experiments with online discussions, first explains why fines need to be sifted out, then provides two practical solutions—one is to control the amount added back to within 10% of the total dose and reduce the water volume accordingly; the other is to add the fines after the second pouring stage to reduce the risk of negative flavors. The article also records measured data from sifting 2.5 g of fines from 15 g of grounds, and notes that high-precision grinders also produce fines; the key is proper management rather than simply removing them. [more…]

Many people, after drinking an Americano or espresso, notice some fine black particles settling at the bottom of the cup—are these actually coffee grounds? And why are they rarely seen in iced drinks? Drawing on Front Street Coffee's practical experience in production, this article explains the sources of very fine particles in espresso extraction, including grinding particle size, the mesh of the portafilter basket, and cleaning of the group head, and offers four actionable improvement measures. The article also records the results of Front Street's test of placing a circular filter paper in the portafilter basket—although it effectively intercepts fine particles, the extraction flow rate and flavor change, requiring readjustment of the grind and dose parameters. [more…]

When extracting espresso, you may occasionally notice a layer of fine black sediment at the bottom of the cup, and many people worry that this indicates an equipment malfunction or spoiled coffee. In reality, these black particles are simply coffee fines—extremely small particles that can easily pass through the holes in the portafilter basket and mix into the coffee liquid under high pressure. At first they hide within the crema, and only as the bubbles burst do they sink to the bottom of the cup and become visible to us. Moka pots also use pressure extraction, so a similar situation can occur. Although coffee grounds are a woody fiber, the extremely fine particle size and tiny intake amount pose no health risk, so you can drink with complete peace of mind. This article explores the origins of fines, whether the portafilter basket will deform, and fine particle size, helping coffee enthusiasts better understand these common phenomena. [more…]

In the practice of pour-over coffee, fines are often seen as the culprit behind clogging and bitterness, and many people have thus developed the habit of always sifting out fines before brewing. But do fines really only have negative effects? From the perspective of Front Street, this article systematically sorts out the definition of fines, their generation mechanisms, and their actual contribution to flavor, explaining why in most cases it is unnecessary to completely sift out fines, and under what conditions sifting should really be considered. At the same time, the article also explores the relationship between coffee bean brittleness, grinder quality, and the amount of fines, helping readers build a more complete understanding of extraction. [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 people notice a layer of fine black powder at the bottom of the cup after finishing a latte or espresso, and sometimes dark particles float at the bottom of an iced latte as well. Is this actually normal? Does it affect flavor or health? In fact, this sediment consists of ultra-fine particles that pass through the filter basket holes during espresso extraction. A trace amount is normal, but if a large amount of grounds is visible to the naked eye, it means something has gone wrong in the extraction process. This article starts with where these fine particles come from, analyzes possible factors such as grinding, the portafilter basket, and barista technique, and offers practical solutions like adjusting the grind setting, switching baskets, and adding a paper filter, to help you enjoy a cleaner cup of coffee. [more…]

Faced with the dazzling array of coffee grinders on the market, many coffee enthusiasts find themselves paralyzed by choice. In truth, the coffee world has never had a single standard—different burr sets each have their strengths and weaknesses. Starting from burr types, this article takes a deep dive into the structural differences between flat burrs, conical burrs, and ghost-tooth burrs, along with their real-world impact on particle shape, extraction results, and final flavor. It also includes practical grind-setting parameters for commonly used models such as the Fuji Royal, Feiying, and Zheng Huang Hang, helping you find a grinding approach that suits your brewing method and taste preferences. [more…]

There is no unified quantitative standard for coffee grinding, so enthusiasts often use everyday ingredients as analogies to quickly convey the concept of particle size. Common reference points like fine granulated sugar, coarse granulated sugar, sea salt, fine salt, and flour each correspond to different brewing methods and roast levels. This article goes through the particle size characteristics and suitable scenarios for each of these analogous grinds one by one: fine granulated sugar is mostly used for light-roast pour-over, coarse granulated sugar suits medium-dark roast beans, sea salt-like texture is suitable for immersion extraction methods like the French press, fine salt-like texture serves the fast-paced extraction of the moka pot, and flour-like texture is divided into two categories: espresso and Turkish coffee. The grind size described by each analogy is a range, not a single fixed value, and understanding this point helps with more flexible grind adjustment. [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…]

Many coffee enthusiasts are in the habit of tapping the dripper during pour-over to level the coffee bed, believing this promotes more even extraction. But you may not know that frequent or forceful tapping can actually trigger the "Brazil nut effect," causing fine particles to sink to the bottom and coarse particles to float up, leading to two negative outcomes: first, during blooming, hot water struggles to evenly saturate all the coffee grounds, and the fine particles at the bottom stay dry, resulting in under-extraction; second, the fine particles clog the pores of the filter paper, prolonging the extraction time and causing over-extraction. Through repeated testing, Front Street Coffee has found that when using a conical dripper and denser coffee grounds, digging into the bed after multiple taps often reveals dry clumps at the bottom. So how should an uneven coffee bed be handled? And what should you watch out for when tapping? This article will break it down for you in detail. [more…]

Many coffee enthusiasts have experienced this impulse while brewing: the moment they see an uneven coffee bed, they want to tap the dripper to level out the grounds. Yet this seemingly reasonable action can trigger a chain of negative reactions—fines sinking, the filter paper clogging, extraction time stretching out, and ultimately a bitter, over-extracted cup. Through comparative experiments, Front Street Coffee found that a tapped coffee bed took 21 seconds longer to complete extraction than an untapped one, with a noticeably bitter taste. The key principle behind this is the Brazil nut effect: vibration causes large particles to rise and fines to sink, clogging the pores of the filter paper. This article will analyze the causes of this phenomenon in detail and offer the correct methods for distributing the grounds and remedying the situation. [more…]

The grind size in coffee directly affects the contact area between the coffee and water as well as the extraction time, and it will directly impact the coffee's taste. But at the same time, coffee grind size is also the biggest headache for many people! In this article, Front Street will explain how to determine the appropriate grind size for different coffee beans. First [more…]

Among the parameters of pour-over coffee, Front Street believes that grind size is the hardest to master. It doesn't have intuitive data like water temperature or coffee-to-water ratio, nor can it be compensated for through practice like technique. As a result, many beginners are stumped by grind size. So Front Street will teach you how to get grind size right. First, I [more…]

The first step in coffee brewing often begins with grinding. Different extraction methods have different requirements for coffee grounds: a French press needs coarse particles visible to the naked eye, while a Turkish pot requires a grind as fine as flour. At the same weight, the finer the grind, the greater the number of cuts and the larger the surface area, and the more opportunities water has to contact the coffee grounds, so flavor compounds are released faster. To move away from vague descriptions like "as coarse as granulated sugar," Front Street Coffee uses standard sieves to calibrate particle size: generally, pour-over coffee particles are between 600-850 microns; when tested with a 0.85 mm (No. 20) sieve, the pass rate is about 80% for light roasts and about 65-70% for medium-dark roasts. This article will also compare the pass rates of common methods such as cold drip, siphon, moka, American drip filter, cupping, and French press, and introduce the effects of conical burrs, flat burrs, and ghost teeth burrs on grinding results, as well as recommendations for choosing between hand grinders and electric grinders. [more…]

Grind size is one of the core variables determining the extraction outcome and flavor direction of pour-over coffee. This article systematically examines how coffee particle size affects flow rate and extraction efficiency, compares the typical behaviors when the grind is too fine versus too coarse, and provides reference grind ranges for different brewing devices such as cupping, pour-over, espresso, moka pot, cold brew drip, and French press. It also introduces the calibration method using the No. 20 sieve pass-through rate to help you find the appropriate grind setting between medium-light and medium-dark roasted beans. The article also incorporates Front Street Coffee products such as Huakui, Geisha, Sidra, PWN Golden Mandheling, Queen's Estate, and Blue Mountain No. 1, offering corresponding grind recommendations and extraction approaches. [more…]

Grinding is the key step that determines coffee flavor, and the choice of grinder directly affects what ends up in the cup. This article begins with the structure and classification of grinders, analyzes the suitable scenarios for manual and electric grinders respectively, and explains the two major points that must be paid attention to when grinding coffee beans: suppressing frictional heat and maintaining particle uniformity. For different brewing devices, the article provides grinding coarseness recommendations ranging from fine powder to medium particles, and also discusses the flavor differences between crushing and grinding. For Espresso enthusiasts, the article emphasizes the importance of fine adjustment functionality, and compares the effects of different burr structures on extraction results. In addition, the article also recommends related products from Front Street Coffee for readers to refer to when purchasing. [more…]

Grind size is a core variable in pour-over coffee that cannot be avoided, as it simultaneously affects the contact area between water and coffee grounds and the extraction rhythm, thereby determining the flavor direction in the cup. This article starts with coffee bean freshness and resting, explains the difference in extraction yield between fine and coarse grounds, and describes the corresponding taste performance when the grind is too fine or too coarse. It also introduces the method of calibrating grind with a 0.85mm cupping sieve, as well as Front Street Coffee's comparison table of applicable equipment organized by five levels—extra fine, fine, medium-fine, medium, and coarse—to help you find the appropriate grind range across different roast levels and brewing tools. [more…]

For more specialty coffee knowledge, please follow: Front Street Coffee (Frontsteet Coffee). In coffee, the coarseness of the grind directly affects the contact area between coffee and water as well as the extraction time, and it will directly affect the taste of the coffee. But at the same time, the coffee grind size is also what gives many people the biggest headache. [more…]

How should you determine the grind size for pour-over coffee? This is the first challenge many coffee enthusiasts encounter when getting started. This article systematically introduces three methods for judging grind size—visual analogy, grinder setting reference, and sieve calibration—analyzing the pros, cons, and applicable scope of each, and further introduces the advanced concept of "particle size distribution" to help understand how grind uniformity affects extraction. At the same time, Front Street Coffee, drawing on its own brewing framework, shares how to combine visual observation, data, and brewing tests to find the pour-over grind size that suits you in a more practical way. [more…]