How Long Does It Take to Rest Roasted Coffee Beans? What's the Optimal Resting Time for Different Roast Levels?

For those who brew their own coffee, you may have some concept of the term "coffee resting." For friends who haven't heard of it, don't worry - let's explore why coffee needs resting and how long it should rest.

When brewing coffee, the moment water touches the coffee grounds, the coffee begins to bloom. "Watching the coffee slowly expand and swell" is a scene everyone enjoys, but without proper resting, the blooming state will likely result in chaotic gas release with countless large bubbles emerging.

Most people (especially Cantonese) have an obsession with fresh ingredients - everything should be enjoyed fresh and hot. However, when it comes to coffee beans, this is something that absolutely cannot be rushed. When coffee beans are freshly roasted, they don't have much aroma at this point, only emitting roasting flavors. At this stage, coffee beans contain abundant carbon dioxide and are very active (like a small child, running around everywhere, unable to stay still).

When brewing at this time, you'll encounter significant obstacles. If the coffee grounds haven't released all gases during blooming, it will affect the subsequent extraction of flavor compounds. During the later extraction process, the coffee bed will continue to bubble and release gas, creating turbulence and causing uneven extraction. This makes it much more difficult to brew a delicious cup of coffee.

After about 4 days of resting, roasted coffee beans will release 60-70% of their gases. After that, the gas release becomes less urgent, slowly releasing small amounts over time. At this point, the coffee beans will stabilize (like a mature adult, calm and composed, exuding charm). The coffee bean's flavor will then approach its peak state, followed by a gradual decline in flavor as the gases slowly dissipate.

The swelling of coffee bags indicates that the coffee beans are releasing gas. Degassing is a continuous process. Once all gases are released, it means the coffee beans are no longer fresh, and naturally, the flavor is almost gone. Therefore, the flavor development of coffee is closely related to the degassing process. After intense degassing, coffee flavor reaches its peak, then gradually declines as the gases slowly dissipate. Resting coffee beans is precisely about allowing them to reach their peak flavor performance.

How to Determine Peak Flavor

So how can we know when coffee beans have reached their peak flavor? There's no precise data for this, including roasters' recommendations, which are merely suggestions and cannot guarantee that 7 days of resting will yield the best flavor (it could be day 8 or day 9).

The length of the resting period for coffee beans is influenced by three factors: the degree of roast, the coffee roasting style, and the heat transfer method used during roasting.

Let's first discuss how the heat transfer method affects the resting time. Current methods are generally divided into direct flame, semi-direct flame, and hot air. Among these three roasting methods, direct flame typically requires a longer resting time, followed by semi-direct flame, and finally hot air.

In terms of roast degree, light roast coffee generally has a shorter resting period than dark roast coffee. Taking FrontStreet Coffee's semi-direct flame roasting as an example, medium-light roast coffee beans typically rest for about 4-7 days, while medium-dark roast coffee beans require about 7-10 days to reach optimal flavor.

Coffee roasting style is much like a coffee roasting competition - using the same beans, each competitor's roasted coffee will have differences, which is the roasting style. Regarding the impact on coffee resting period, some coffee roasters prefer fast-paced roasting, while others like to slow down the process. The resulting beans might have the same primary flavors, but other delicate flavors will differ, including the resting period.

Therefore, the 4-7 day resting period mentioned by FrontStreet Coffee doesn't necessarily apply to all coffee beans. FrontStreet Coffee's conclusion is based on their own roasted coffee beans and should theoretically apply only to FrontStreet Coffee's roasted beans. However, adjustments should still be made based on actual circumstances.

How Consumers Can Determine Resting Period

So as consumers, how should we determine the resting period for coffee beans? First, as consumers, you must clearly understand that each roaster has a different style, so don't forcefully apply Store A's resting recommendations to Store B's beans. Then, you must know the roasting date of the coffee bag.

If you're dealing with coffee beans from the same roaster, the roasting style will be consistent, allowing you to deduce based on patterns. First, we need to understand that the fundamental purpose of resting coffee beans is to enjoy a cup of coffee at its peak. This requires starting from reality and using your senses to explore. When encountering an unfamiliar coffee bean, you can brew a cup daily to taste its flavor and compare today's taste with yesterday's.

When you notice that the coffee flavor is improving day by day, and then suddenly one day the aroma and flavor slightly weaken, that turning point is the resting period. You can use this period as a reference for future coffee beans of the same type. You won't need to taste every bag of coffee beans every day in the future, since opening the coffee bag each time also affects the state of the coffee beans.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473