Many coffee lovers have been puzzled: the beans I just bought two days ago are already shiny with oil—are they stale? Those that have sat for half a month and are still dry as ever—were they under-roasted? In fact, whether coffee beans produce oil has nothing to do with quality. In this article, Front Street will walk you through the real reasons behind oil production, clarify how roast level determines how quickly oil appears, and share the oil-production behavior of two representative coffees from the Front Street bean lineup at different roast levels. Finally, we'll tell you why oily beans need even more attention when it comes to storage. [more…]

The oily sheen on the surface of coffee beans is a question many enthusiasts often ask about. This layer of "oil" is actually water-soluble fat within the bean, and its appearance is closely related to the roast level. Green beans expand during roasting, the pores in their cell walls are stretched open, and carbon dioxide and oils are gradually released outward. Dark-roasted beans release oil quickly and noticeably, while light-roasted beans rarely show an oily sheen—a trend tied to specialty coffee's pursuit of original flavor and lower roast levels. Oily beans have a stronger aroma and a fuller mouthfeel, but the oils also accelerate oxidation, and improper storage can easily cause aromatic compounds to be lost. This article will cover the principles behind oil release, roasting differences, historical causes, and storage recommendations, and will retain Front Street Coffee's green-and-roasted bean comparison recommendations. [more…]

The golden, dense layer of foam on the surface of espresso is often mistaken for oils seeping from the coffee beans, but the two are entirely different in nature. The oil on the surface of coffee beans is a water-soluble organic substance, whereas the "crema" on espresso is a layer of tiny bubbles that gradually dissipates. Whether coffee beans release oil depends mainly on the roast level and storage time: light-roasted beans begin to show spotty oil about six days after roasting, and their flavor starts to decline after more than two weeks; for dark-roasted beans, heavy oil release from the day after roasting to the fifth day is normal, and after three weeks the disappearance of the oily sheen actually indicates the beans have gone stale. Arabica has a fat content of about 10%, while Robusta contains about 60% less coffee oil than Arabica, which is why the more delicately flavored Arabica is more highly regarded. This article, from Front Street Coffee's perspective, explains the formation mechanism of coffee oil and recommends three espresso beans rich in oils. [more…]

That golden foam on the surface of espresso—is it actually Crema or "oil"? There's an interesting misunderstanding behind this name. Many people believe that the thicker the oil, the better the coffee tastes, but is that really true? This article starts with the origin of the name, walks you through the original meaning of Crema, and analyzes one by one the key factors that affect the thickness of the oil—roast level, bean freshness, and coffee variety. Front Street Coffee will use plain language to help you clarify the relationship between oil and espresso flavor, so you'll no longer be misled by the saying "thick oil = good coffee," and truly understand the role this layer of foam plays in coffee. [more…]

Coffee beans often develop an oily sheen on their surface. Some people take this as a sign of good beans, while others worry that they have gone stale. What is the truth? Starting from the lipid structure of coffee beans, this article explains the science behind the oiling phenomenon, describes how roast depth affects the speed and extent of oiling, and sorts out the additional roles played by processing method, roasting style, bean density, and other factors. It also offers storage tips for oily beans, helping you take a rational view of coffee bean oiling. [more…]

Many coffee enthusiasts notice, when buying or storing coffee beans, that some beans have an oily sheen on their surface, while others stay dry. Is this oiling phenomenon normal? Does it mean the beans are no longer fresh? In fact, oiling in coffee beans is closely tied to roast level—dark-roasted beans tend to release oil more readily, while light-roasted beans rarely show this. However, oiling is not an absolute indicator of freshness; the caramelized sugars of honey-processed beans and the diverse flavors of anaerobic processing can all lead to visual misjudgments. Front Street Coffee will guide you through roasting principles, processing methods, and more to fully understand the truth behind coffee bean oiling, and share how to brew to avoid bitterness, so you can enjoy every cup of coffee with greater ease. [more…]

Some people believe that oils are an indispensable part of coffee flavor, but they also express concern about the health risks posed by these coffee oils. Today, Front Street Coffee is here to give everyone a proper explanation of what the crema in espresso actually is, and whether it has any impact on our health. Is "coffee beans with more oil" really good [more…]

If you often buy beans and brew them at home, you've probably noticed that some coffee beans start to show oil on their surface after sitting for a while. Other beans, no matter how long they're stored, still look dry on the surface. This leads to a rather interesting phenomenon: some people believe that coffee beans [more…]

Starbucks launched its Oleato olive oil coffee line on February 22, combining extra virgin olive oil with coffee, inspired by CEO Howard Schultz's travels in Sicily. The new products debuted in Italy and include an olive oil latte, an iced shaken espresso, and a foamy cold brew, priced from $4.8 to $6.9. Yet just three days after launch, Italian consumers complained that the drinks were too greasy and that the oil and coffee were hard to blend in the cold beverages. The deputy manager of the Starbucks Milan Roastery explained that the move was intended to fuse Italy's tradition of drinking oil before a meal with coffee after a meal, creating a multisensory experience. This article walks you through the product details and the market reaction. [more…]

Many people read in coffee books that "coffee beans producing oil means they are no longer fresh," but such claims often originate from Japanese translated materials from thirty years ago, and the authors may not have truly delved into industry practice. Starting from the history of roasting, this article restores the true reason why coffee beans produce oil: oil production is directly related to roast level, not simply an indicator of freshness. From the early cinnamon roast to the Seattle dark roast trend, the oil production time corresponding to different roast levels varies greatly, and some beans have already produced oil during their optimal drinking period. Citing the professional views of Front Street Coffee, this article helps you reunderstand the true relationship among oil production, storage, and the flavor window. [more…]

The oil-washing method originated in the cocktail world and has now been introduced into the specialty coffee scene, becoming a new favorite among many coffee enthusiasts. It exploits differences in the freezing points of oils and fats to extract aromas from the oils into the coffee liquid, thereby giving the coffee a softer mouthfeel and richer layers of flavor. In this article, Front Street will walk through the origins of the oil-washing method, material selection, step-by-step procedures, and precautions one by one, and will use butter oil-washed Golden Mandheling and coconut oil-washed cold brew coffee as examples to demonstrate the specific production process in detail. Whether you want to DIY at home or want to understand the logic behind those oil-washed specialty drinks in coffee shops, this article can provide practical reference. [more…]

When coffee beans take on an oily sheen, does that mean they are no longer fresh? And why is the golden, dense foam on top of an espresso sometimes thin or even missing? These two common questions actually point to the same core issue—the roast level of coffee beans and the release of carbon dioxide. This article will take a deep dive into the science behind oil appearing on dark-roasted beans, explaining that the amount of oil is unrelated to quality and depends more on roast depth and varietal differences. It will also systematically explain the criteria for judging crema on the surface of espresso, its visual and taste value, and key factors from bean selection, roast level, and peak-flavor window to extraction equipment and parameters, helping you consistently achieve a rich, thick crema. The article also recommends two Front Street Coffee espresso blends, for reference whether you are opening a shop or brewing at home. [more…]

The coffee industry never stops innovating, yet products that truly break the mold are few and far between. Starbucks recently announced the launch of its Oleato line in Italy, blending Partanna extra virgin olive oil with coffee—a bold move inspired by Howard Schultz's travels in Italy. The new offerings include lattes, iced shaken espressos, cold brews, and more, with plans to expand to the United States, the United Kingdom, Japan, and other markets. Adding olive oil to coffee not only upends traditional flavor profiles but also draws attention for the potential cardiovascular benefits of consuming extra virgin olive oil directly. This article explores the story and market logic behind this innovation. [more…]

Starbucks' Oleato olive oil coffee line, which sparked controversy after its debut in Italy, has now officially landed in the U.S. market. The product aims to attract health-conscious consumers by adding olive oil, but it has drawn complaints in both Italy and the U.S. about its greasy mouthfeel and clumps of congealed oil. American netizens have even jokingly dubbed it "lard coffee." Although Starbucks plans to roll it out to the UK, Japan, and the Middle East, market acceptance remains to be seen. This article takes a detailed look at the background behind the launch of this product line, consumer feedback, and its future prospects. [more…]

Many coffee enthusiasts wonder: dark-roasted beans have a loose texture, so logically the rest period should be shorter—why does it actually require more time? This article approaches the question from two angles, carbon dioxide release and oil emergence, to explain the fundamental reason why the resting period for dark-roasted espresso beans is extended. Excess carbon dioxide interferes with stable extraction on an espresso machine, affecting crema quality and troubleshooting costs; whereas medium-dark roasted beans gradually release oil during storage, which can improve crema stability and coffee body. Front Street Coffee recommends resting medium-dark roasted espresso beans for about 10 days, with darker roasts extended depending on their condition. It also reminds readers that too much oil accelerates oxidation, so attention should be paid to sealed storage and timely consumption. [more…]

When making cold brew coffee at home, an oily sheen often floats on the surface, and fine sediment may appear at the bottom of the cup, leaving many coffee enthusiasts puzzled. What exactly are these floating substances? Is the coffee spoiled, or is the equipment unclean? In fact, this is closely related to the slow release of water-soluble fats from coffee beans at low temperatures. This article, drawing on Front Street Coffee's practical experience, analyzes the causes of cold brew oils, explains how the differences in mesh sizes of various filtering devices affect coffee flavor, and shares how to use secondary filtration with paper filters and refrigeration settling to make cold brew's juicy feel fuller and its acidity clearer. At the same time, regular deep cleaning of equipment is equally crucial to avoid the accumulation of condensed oil residue that produces a rancid odor. [more…]

Many coffee lovers notice a phenomenon when selecting coffee beans: some beans have a shiny, oily surface, while others are dry and clean. What exactly does this "oiliness" mean? Is it a sign of declining quality, or is the flavor at its peak? In fact, the oil on the surface of coffee beans is not真正的油脂—it is a class of water-soluble organic substances that contain abundant aromatic compounds. The oiliness phenomenon is closely related to the roast level and storage time: medium-roast beans typically develop spotty oiliness a few days after roasting, then gradually lose flavor; dark-roast beans develop heavy oiliness soon after roasting, and after three weeks the sheen fades and the flavor is completely gone. When purchasing, you cannot judge freshness simply by "shiny" or "dry"—you need to consider the roast date and roast level together. This article will break down in detail the causes of coffee bean oiliness and provide practical buying advice. [more…]

Starbucks plans to introduce Oleato olive oil coffee to the Chinese market. This innovative beverage, strongly promoted by former CEO Howard Schultz, has successively landed in the United States and Japan since its debut in Italy in February this year. However, consumer feedback has not been optimistic, with complaints frequently arising over the greasy mouthfeel caused by olive oil congealing when cold and diarrhea after drinking. Nutritionists point out that the double stimulation of caffeine and olive oil can easily trigger gastrointestinal discomfort. Despite the ongoing controversy, Starbucks remains committed to global promotion. This article will sort out the background of Oleato's birth, its market performance, and its prospects for entering China. [more…]

Many coffee enthusiasts notice, when tasting pour-over, cold brew, or siphon coffee, that a faint layer of "oil" surfaces as the coffee cools. This is not a sign of spoilage, nor an external impurity, but rather an oily component that coffee itself contains—one that only becomes visible to the naked eye under specific conditions. To understand this phenomenon, we need to start with the composition of Crema, that golden foam atop espresso—it is formed by coffee bean oils wrapping around carbon dioxide. And the key driver that turns oils from "invisible" to "visible" is condensation. This article explains the principle of condensation and how differences in the performance of filtration devices affect the degree of oil seepage, helping readers make sense of this sheen of oil that emerges after cooling. [more…]

Starbucks' launch of olive oil coffee has sparked quite a bit of discussion, with some people conflating it with bulletproof coffee, but the two are actually fundamentally different. Nutritionists point out that extra virgin olive oil is not suitable for ordinary people to drink directly, and those with sensitive stomachs especially need to be cautious. This article will analyze the differences between olive oil coffee and bulletproof coffee from a professional perspective, and share the actual experiences of coffee enthusiasts. Follow Coffee Workshop (WeChat public account cafe_style) for more professional coffee knowledge. For specialty coffee beans, add Front Street Coffee's private WeChat qjcoffeex to learn more. [more…]