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…]

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…]

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…]

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…]

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…]

Grind size is one of the key variables determining coffee flavor. The finer the particles, the larger the contact area between hot water and coffee grounds, and the greater the resistance to extraction, which tends to prolong extraction time and increase the extraction yield; the coarser the particles, the opposite is true, and underextraction becomes likely. Different brewing devices have significantly different grind requirements, ranging from the flour-like extremely fine powder for a Turkish pot to the coarse particles for a French press, a very wide span. This article systematically sorts out the relationship between grind size, extraction time, and extraction yield, gives reference grind ranges for espresso and pour-over coffee, and, combined with Front Street Coffee's production experience, explains how to find a grind setting that suits you according to roast level and bean hardness, while also reminding you of the importance of daily maintenance of the grinder burrs. [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…]

Many coffee enthusiasts will notice that the iced Americano they make sometimes isn't as clear and bright as they expect, but instead shows a visibly cloudy state. Where exactly does this cloudiness come from? Does it mean there's a problem with the coffee quality? This article will start from the extraction principles of espresso, and combine a comparative experiment between two beans—Front Street Coffee's Huakui SOE and Front Street Coffee's classic blend—to deeply analyze how factors such as very fine particles, roast level, coffee freshness, and hot-versus-cold differences affect the appearance of iced Americano, while also discussing the unexpected value these suspended particles bring to coffee flavor. [more…]

Summer is here, and many people enjoy making cold brew coffee at home, but the filtration step often proves troublesome—the coffee liquid drips extremely slowly, sometimes taking half a day. Why is cold brew filtration so slow? The core reason is that the extremely fine particles in the coffee grounds clog the pores of the filter paper, leaving insufficient channels for the liquid to flow through. This is especially true when making multiple servings at once, as the waiting time gets stretched even further. This article will first explain the causes of clogging, then share three methods commonly used by baristas to speed up filtration: using a filter bag or cloth to pre-isolate the coffee grounds, spreading the coffee grounds at the bottom of the filter paper to intercept fine particles, and using a vacuum filtration device to achieve rapid filtration under reduced pressure. Each approach has its own pros and cons, suiting enthusiasts with different needs, and the article also retains relevant experience and product recommendations from the Front Street Coffee brand. [more…]

When making cold brew at home, the most frustrating part is usually the filtering stage—the coffee liquid drips slower and slower, and even after more than ten minutes it still hasn't finished filtering, with the filter paper completely clogged by fine particles. Why is the filtering speed of cold brew so much slower than pour-over at the same grind size? The main reason is that fine particles clump together and block the pores of the filter paper. Through comparative experiments, Front Street Coffee has summarized three efficient and practical cold brew filtering techniques: cold brewing directly in a non-woven filter bag, insisting on stirring before straining out the grounds, and using coarse coffee grounds as a base layer to intercept fine particles. This article breaks down the principles and operational details of each method one by one, helping coffee lovers quickly enjoy a cup of full-flavored homemade iced coffee even on a busy morning. [more…]

For more specialty coffee knowledge, please follow: Front Street Coffee (Frontsteet Coffee). The coarseness or fineness of the grind in coffee directly affects the contact area between the coffee and water as well as the coffee 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…]

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…]

Many coffee enthusiasts buy beans to take home after enjoying a satisfying cup at a café, only to find that their own brews always seem to fall a bit short. To address this common frustration, Front Street Coffee has identified the four most error-prone stages: grind size, pouring technique, coffee-to-water ratio, and water temperature. Starting with the shape of the coffee bed after brewing, the article teaches you to judge where the problem lies by examining particle coarseness, muddiness, and drainage speed; it then analyzes the causes of weak or overly sour flavors from the details of pouring; and finally offers practical recommendations on coffee-to-water ratio and water temperature. Whether you are a beginner or looking to refine your technique, this systematic breakdown will help you find the right direction for adjustment. [more…]

After extracting espresso, the golden, dense foam on the surface is the Crema. Sometimes this layer of crema develops brown streaks of varying shades, resembling tiger stripes, which enthusiasts call "tiger-striped espresso." How exactly do these patterns form? Does it mean the coffee tastes better? Front Street Coffee will start from the composition of the crema, analyze the origin of the tiger stripes, and compare the respective advantages of tiger-striped espresso and regular espresso in terms of body and cleanliness, helping coffee lovers view this phenomenon more rationally. [more…]

When making espresso-based Americano, some people are in the habit of placing a filter paper at the bottom of the portafilter basket—what changes does this actually bring? Starting from a comparative experiment at Front Street, this article analyzes the specific effects of filter paper on coffee cleanliness, aroma, body, and flavor layering. Filter paper can intercept the fine particles in espresso, making the Americano taste cleaner, but it may also weaken the aroma and solid mouthfeel brought by lipids. Through a comparison of two cups of Strawberry Candy Espresso Americano, the article demonstrates the significant difference between using and not using filter paper, and explains why other espresso drinks such as lattes usually do not adopt this practice. Ultimately, the choice depends on whether you want a clean, light Americano or a coffee with a solid, richly layered flavor. [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…]

The coarseness of the grind in coffee directly affects the contact area between the coffee and water as well as the extraction time, and it will directly impact the taste of the coffee. But at the same time, the coffee grind size is also the most headache-inducing aspect for many people! In this article, Front Street will explain how to determine what the grind size should be for different coffee beans. First, [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…]

The grind size of coffee directly affects the contact area between coffee and water as well as the extraction time, and it will directly impact the taste of the coffee. But at the same time, coffee grind size is also the most headache-inducing thing for many people! In this article, Front Street will discuss how to determine what the grind size should be for different coffee beans. First [more…]