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Impact of Coffee Bean Roast Levels and Grind Sizes on Cold Brew Coffee Flavor - Cold Brew Coffee Bean Recommendations

Published: 2026-01-27 Author: FrontStreet Coffee

Last Updated: 2026/01/27, Professional coffee knowledge exchange. For more coffee bean information, please follow Coffee Workshop (WeChat official account: cafe_style). Sipping freshly brewed coffee, smelling the coffee aroma, experiencing the bitterness, acidity, and sweetness of coffee and coffee beans—there are many factors that affect the differences in coffee flavor, such as the growing origin of coffee beans, post-harvest processing, and the depth of roasting. For coffee lovers like you, perhaps not

Understanding Coffee Flavor: The Journey from Bean to Brew

As you savor your freshly brewed coffee and inhale its aromatic essence, experiencing the interplay of bitterness, acidity, and sweetness, you might wonder about the factors that create these distinctive flavor variations. The differences in coffee flavor are influenced by numerous elements, including the growing region of coffee beans, post-harvest processing methods, and the degree of roasting. Even if you're a coffee enthusiast who hasn't yet explored the subtle nuances of different coffee bean flavors, now is the perfect time to join FrontStreet Coffee in rediscovering how coffee beans develop their captivating aromas and charm!

The Impact of Coffee Roasting Levels on Flavor

Roasting represents the final stage in the complex transformation of coffee from an agricultural product to the roasted beans we grind, brew, and enjoy. We refer to unroasted coffee beans as "green beans," named for their distinctive green color. Prior to roasting, these green beans are dense and nearly flavorless, with a grassy aroma. It's only through the heating process of roasting that the prized coffee flavors and aromas are released, making the coffee more soluble and ready for brewing. Roasting is an indispensable step in our pursuit of delicious coffee, carefully balancing both art and science.

When we describe coffee as light, medium, or dark roast, we're referring to what's known as the roast level. The visible color of coffee beans correlates directly with the caramelization of sugars—the longer the heat exposure, the deeper the roast color and the higher the degree of caramelization in the coffee. Finding your preference for a particular roast level is crucial for enjoying your coffee experience, because the same coffee can taste dramatically different depending on the roast degree.

FrontStreet Coffee's Roasting Philosophy

FrontStreet Coffee's roasters create different roasting curves based on the unique characteristics of each coffee bean variety.

FrontStreet Coffee's roasting process for Ethiopian coffee beans

Ethiopian coffee beans are known for their delicate and refined flavors. To highlight their floral and fruity notes, FrontStreet Coffee's roasters choose lighter roast levels that preserve more of the original sugars and plant-based flavors and aromas, resulting in a coffee that is brighter and more complex. Take FrontStreet Coffee's COE22, for example—the cinnamon-colored roast perfectly showcases the various fruit flavors in the coffee, including citrus and lychee, with distinctly noticeable fermented wine-like aromas.

Medium roasted Kona coffee beans at FrontStreet Coffee

Medium-roasted Kona coffee is prized for its balanced, smooth nectar sweetness and elegant, full-bodied texture. FrontStreet Coffee's roasters select a medium roast, and the cupping results reveal:

The brewed coffee releases a mulberry aroma that brings a sweet sense of happiness, while the aftertaste is a smooth malt bitterness that glides down the throat—a wonderful journey begins!

Dark roasted coffee beans at FrontStreet Coffee

At FrontStreet Coffee, dark-roasted beans are few and far between—basically limited to Indonesian varieties that undergo dark roasting. This is because dark-roasted coffee beans can be too bitter and intense for the average customer. All espresso-based coffees in coffee shops are dark roasted, because dark-roasted coffee takes on a deep brown color, and the oils in the coffee beans rise to the surface due to the heat applied during the roasting process, creating coffee with abundant oils that pairs perfectly with milk—truly a match made in heaven. Aged Mandheling is an example of dark-roasted coffee. Because Mandheling green beans have high density and aged coffee has less moisture, fire adjustments at each stage require special care to prevent the surface oils from burning.

The Impact of Grind Size on Cold Brew Coffee

The appropriate grind size is crucial for coffee brewing! Regardless of your brewing method, coffee making involves extracting flavors (and caffeine) from the coffee grounds. The finer the coffee beans are ground, the greater the exposed surface area of the grounds, leading to faster extraction. If your coffee tastes sour and watery, it might be because your beans are ground too coarsely. If the coffee flavor is overly bitter (assuming we've ruled out issues with roast level and origin), you might need a coarser grind to improve the taste. This is why coffee for espresso machines is ground so finely—because the water in an espresso machine passes through the coffee grounds very quickly under high pressure. On the other hand, cold brew coffee is made with coarsely ground coffee because this cold extraction method allows the coffee to remain in contact with water for a longer period. The extraction time for espresso is approximately 30 seconds, while cold brew coffee takes an entire afternoon.

When FrontStreet Coffee makes cold drip coffee, the typical grind setting used is EK43S 10.

Cold Brew Coffee Bean Recommendations

FrontStreet Coffee believes that regardless of the roast level, any coffee can be suitable for cold brew after adjusting various parameters (such as extraction time, grind size, etc.) according to personal flavor preferences.

When you want to add milk to your cold brew coffee, dark-roasted love coffee is one of the best options for cold brew. Friendly reminder: dark-roasted coffee beans require less steeping time than light-roasted beans—if left for too long, the dark-roasted flavors tend to become even more intense.

Many people think that medium-roasted coffee beans are most suitable for cold brew coffee because they have balanced aromas and flavors. Friendly reminder: extra-coarse grinding will maximize the extraction of medium-roasted coffee flavors.

FrontStreet Coffee typically uses light-roasted coffee for cold drip coffee. Light-roasted coffee has very high acidity, which is why FrontStreet Coffee recommends using this love coffee for cold brew. Chilling for over 16 hours reduces the acidity, allowing you to enjoy smooth and flavorful coffee.