The production of fines when grinding coffee beans is a normal phenomenon. A moderate amount of fines contributes positively to flavor; what truly causes trouble is excessive fines. Front Street Coffee has noticed that many coffee enthusiasts feel a sense of dread at the mere mention of fines, mostly because they have been tormented by clogged beds that won't drain, scorched bitterness, and astringency. This article first defines what particle size counts as fines, then explains the relationship between the causes of fines and the type of burr set, with a focus on comparing the differences among flat burrs, ghost-tooth burrs, and conical burrs in terms of grind uniformity and fines ratio. Finally, it offers two practical solutions: sifting out fines and adjusting brewing technique, along with rescue strategies for the common situation of abundant fines accompanied by coarse grounds that are also too coarse. [more…]

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…]

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…]

In the coffee grinding process, the production of fines is almost an unavoidable phenomenon, regardless of whether one uses expensive professional-grade grinders or entry-level manual grinding equipment. However, the proportion of fines directly affects the stability of brewing and the final flavor presentation. Choosing a suitable grinder can, to a certain extent, help us reduce the troubles caused by fines. Front Street Coffee specifically conducted a comparative test on the differences in fines generation between manual coffee grinders and electric coffee grinders, analyzing the differences in grinding performance between the two from the perspective of burr structure, helping coffee enthusiasts more clearly understand the characteristics of different devices in grinding function, so as to make choices that better suit themselves. [more…]

When encountering slow drainage and muddy flavors during pour-over coffee brewing, many people's first reaction is to blame the fines, so they buy a sieve to try to solve it. But after sifting out the fines, the clogging does improve, yet the taste becomes flat and dull—why exactly is that? What role do fines actually play in extraction? Starting from a real confusion shared by a friend with Front Street Coffee, this article discusses the dual nature of fines, the actual effect of sieves, and the reasonable direction for choosing pour-over grind size, helping you clarify the balance between grind and flavor. [more…]

The tiger stripe pattern on the surface of espresso is often misunderstood as a sign of over-extraction, but the truth is exactly the opposite. Starting from the composition of the crema, this article explains that tiger stripes are actually a phenomenon in which coffee fines float on the surface of the crema, and analyzes how fines affect extraction, as well as how factors such as grind size, distribution technique, and the distance the espresso falls cause tiger stripes to appear. Front Street Coffee helps you clarify the true relationship between tiger stripes and over-extraction, and understand the role of fines in espresso extraction. [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…]

In the process of making pour-over coffee, grind size and fines handling directly affect the final flavor. This article focuses on the difference between fines and medium-coarse grounds. It first explains the distribution patterns of coffee particles of different sizes and their effects on extraction, then discusses the dual role of fines in extraction—they may introduce off-flavors but can also enhance complexity. The article further analyzes whether fines need to be sifted out before pour-over brewing and offers practical advice: when the proportion of fines is too high and affects flow rate or flavor, they can be sifted out as appropriate. Finally, using "Front Street Coffee" as an example, it introduces its products and store information to help coffee enthusiasts understand the grinding stage more systematically. [more…]

Many coffee enthusiasts, while enjoying an espresso, notice black particles settling at the bottom of the cup and worry whether this means something went wrong with the extraction. In fact, in most cases this phenomenon is perfectly normal. These sediments are extremely fine coffee grounds that have passed through the holes of the portafilter basket, and they usually sink to the bottom gradually after the coffee has rested for a few minutes. This article will explain in detail the principle behind how these fines appear, their relationship with tiger-striped crema, and several factors that may cause a sudden increase in sediment, including grinding too fine and deformation of the basket's mesh. At the same time, Front Street Coffee will also use examples to help you determine when you need to adjust your grinding parameters, so you can face that layer of fine grounds at the bottom of your cup with greater ease. [more…]

Grind size is one of the most critical variables in pour-over coffee—it determines the contact area between water and coffee grounds, and also influences extraction time and the final flavor. This article will systematically sort out the logical relationship between grind size and extraction yield, tell you what kind of taste will appear in the cup when the grind is too fine or too coarse, and also introduce how to use a 0.85mm sieve to calibrate the passing rate, and give specific grinding recommendations for beans with different roast levels. If you do not want to buy an extra sieve, the article also categorizes five levels—extra fine, fine, medium-fine, medium, and coarse—so you can quickly find the right setting by comparing it with your own brewing device. [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…]

Bought Starbucks coffee beans but feel puzzled by the grinder settings? Grind size directly determines the success or failure of a cup of coffee. This article uses common everyday items like fine granulated sugar, coarse granulated sugar, sea salt, fine salt, and flour as analogies to help you quickly find the right grind size for pour-over, French press, moka pot, and espresso machine. Beans of different roast levels have different densities, so the same extraction method requires different grinds. Front Street Coffee will guide you through understanding the particle size range corresponding to each grind state, and why light-roasted beans need a finer grind while dark-roasted beans need a coarser grind, so you no longer have to agonize over grind size. [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…]

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 making of espresso, fines have always been a love-hate presence. They may bring rich crema, but they can also clog the portafilter basket, slow down the flow, and add bitterness. There are two common methods for removing fines on the market: one is to skim off the surface crema after extraction, which is simple and direct; the other is to pre-place a moistened circular filter paper at the bottom of the portafilter basket. The latter sounds gentle, but does it really not interfere with extraction? Front Street conducted a comparative experiment for this: the same 20 grams of coffee, 40 milliliters of liquid weight, one regular extraction, and one with filter paper added at the bottom. The result was that the cup with filter paper took less time, and both concentration and extraction yield were slightly lower, but the fines almost disappeared, and the taste was cleaner. This shows that adding filter paper is indeed feasible, but the grind or parameters must be readjusted to make up for the lost flavor. [more…]

When brewing pour-over coffee, water failing to drain through the dripper is a problem many enthusiasts encounter. The causes of clogging are not singular—too many fines, overly vigorous agitation, and high bean density can all slow the flow. This article starts from these three common factors, analyzing each cause one by one and offering corresponding ways to improve them—including coarser grinding with a slower extraction, using a sifter, and adjusting pouring technique. At the same time, it will explain that clogging does not necessarily mean over-extraction, and whether to make adjustments should ultimately be based on how the coffee tastes on the palate. Front Street Coffee will share its brewing experience with high-density beans, using the Yirgacheffe Giddingding from its own bean list. [more…]

When brewing pour-over coffee, if the filter basket ends up with a thick, muddy bed of grounds instead of distinct, granular particles, it often means the coffee was ground too fine, which easily leads to over-extraction. When faced with the dilemma of pre-ground coffee that cannot be made coarser, besides switching to immersion extraction, there is another distinctive approach using high concentration and low extraction—the mud flow. It uses extremely fine grinding combined with agitation to rapidly dissolve flavor compounds in a short time, then dilutes with hot water, resulting in coffee with a normal extraction yield and full flavor. In this article, Front Street will explain in detail the principles and specific operating parameters of the mud flow, helping you easily tackle the problem of coffee grounds that are too fine. [more…]

Coffee enthusiasts often grind their purchased coffee beans into espresso-level fine powder, yet don't know how to handle it—if operated according to regular pour-over parameters, it easily leads to over-extraction. So, can espresso-grind coffee powder actually be used for pour-over or cold brew? And how should the brewing plan be adjusted? In this article, Front Street Coffee uses medium-dark roasted Front Street Mandheling as an example, analyzing the precautions for pour-over with fine powder one by one, from dripper selection, water temperature setting, coffee-to-water ratio to pouring technique, and provides a practical comparison of two coffee-to-water ratios, 1:15 and 1:10, to help you master fine-grind coffee powder at home and avoid waste. [more…]

Grind size is the key variable that determines the success or failure of a cup of coffee extraction. If the grounds are too fine, they tend to over-extract and become bitter; if the grounds are too coarse, the extraction is insufficient and the flavor is weak. Starting from the practical experience of Front Street Coffee, this article systematically explains the mechanism by which grind setting affects extraction efficiency, sorts out the grind ranges corresponding to different brewing methods such as espresso, pour-over, and French press, and focuses on explaining the setting of the EK43s grinder in the pour-over scenario—medium-light roast beans are recommended at 10, and medium-dark roast beans at 10.5. It also introduces the specific operation of using a 0.85mm No. 20 sieve for sifting verification, helping coffee enthusiasts quickly judge and correct the grind size, so that every cup of coffee can consistently present the ideal flavor. [more…]