What is the Flavor Period of Coffee Beans? Can Pour-Over Single-Origin Beans Still Be Brewed After Their Flavor Period?

Understanding Coffee's Flavor Window

Because coffee's flavor compounds are mostly volatile, unlike most conventional foods, coffee has a special time frame in addition to its shelf life—the "flavor window."

Coffee within its flavor window delivers exceptional flavor performance, as flavor compounds are most abundant during this period, and carbon dioxide content is not as rich as when freshly roasted (though still substantial, its impact on extraction is less significant). This allows us to easily dissolve the flavor compounds from the coffee. However, when coffee beans are stored beyond their flavor window, the brewed coffee's performance will significantly diminish compared to before, as most flavor compounds have dissipated.

These volatile compounds are the primary source of coffee's flavor formation. Once flavor compounds have dissipated, brewing coffee can only yield minimal flavor experience and the inherent soluble taste of the beans themselves. Therefore, FrontStreet Coffee generally recommends consuming coffee beans before the flavor window ends. However, many friends may not finish their beans in time due to taste preferences or having stocked up too much, resulting in coffee beans stored beyond their flavor window.

Coffee beans beyond their flavor window don't necessarily become unpalatable—they simply exhibit less expressive characteristics. They're also more challenging to brew properly, which contributes to their inferior taste. However, by switching to more suitable brewing methods, even beans outside their flavor window can still deliver excellent performance. Before that, we need to learn how to identify whether coffee beans have exceeded their flavor window.

How Long Is Coffee's Flavor Window?

Generally, coffee beans' flavor window extends from the fourth day after roasting until the forty-fifth day. The reason it doesn't start immediately after roasting, as friends who have read FrontStreet Coffee's articles from the past two days would know, is that coffee requires a degassing period to release carbon dioxide that hinders extraction. After this degassing period, the flavor window begins. If we don't consume the coffee beans within approximately a month and a half, the flavor window will close, making the beans more challenging to brew.

One important note is that the degassing time and flavor window duration vary depending on the beans' "constitution." FrontStreet Coffee's "constitution" includes factors like roast degree, density, and storage method. Since these have been shared many times before, we won't elaborate further here.

How to Determine Coffee's Flavor Window?

Two factors can be used to determine this, but they should be used in combination. The first is the taste mentioned earlier by FrontStreet Coffee, and the second is observation—specifically, observing the coffee bed during the blooming phase of brewing. As mentioned previously, coffee beans within their flavor window contain relatively abundant gases, including carbon dioxide. During blooming, due to the presence of these carbon dioxide gases, the coffee bed exhibits two characteristics: it will expand, and it will have strong water retention capacity.

The expansion is familiar to most people, while water retention capacity refers to the coffee bed remaining thoroughly moist from the beginning to the end of blooming. This occurs because the tiny bubbles formed by carbon dioxide cannot initially escape and become trapped within the coffee bed, causing it to expand! Simultaneously, these bubbles also slow down the water's percolation rate. Therefore, when coffee beans are relatively fresh, the abundant gases not only cause the coffee bed to expand during blooming but also maintain its moist state for an extended period. When coffee beans are no longer fresh, gases like carbon dioxide have mostly dissipated. At this point, when we bloom during brewing, not only does the bed fail to expand significantly, but we can also observe the bed's moisture decreasing at a visible rate. Shortly after pouring water, the bed dries out. Therefore, this becomes an observable factor—the coffee bed during blooming. More precisely, it should be the water retention capacity of the coffee bed.

However, some coffee beans still deliver exceptional flavor even after their bed's water retention capacity has diminished, so we need to pair taste assessment to determine if the beans are still sufficiently fresh.

How to Brew Stale Coffee Beans?

When coffee beans are no longer fresh, they become less resistant to extraction. If we continue using the same brewing method, we'll easily produce over-extracted coffee. This is primarily due to excessive extraction efficiency and the lack of gas support, allowing fine particles to settle more easily at the bottom and cause blockages.

Therefore, FrontStreet Coffee recommends adjusting the coffee grind one setting coarser. For example, if you originally used setting 10 on an Ek43 grinder, you can switch to setting 10.5 when the beans have passed their flavor window. Firstly, this reduces the coffee's surface area contact with water, making it relatively more extraction-resistant. Secondly, a coarser grind appropriately reduces the amount of fine particles, making blockages less likely! FrontStreet Coffee uses 15g of coffee as an example, with a coffee-to-water ratio of 1:15, water temperature at 92°C. The specific procedure is as follows! (Suitable only for beans that have recently passed their flavor window, within two months of the roast date)

First, we use 25ml of hot water for a 20-second bloom. (The main purpose of blooming is to release gases. Since the coffee grounds at this point no longer contain abundant gases, the time and water amount can be slightly reduced—just enough to wet the coffee grounds.)

Next, for the second water addition, we pour from the center outward in circular motions with a strong flow to raise the coffee bed, with a total water volume of 125ml. (The purpose of raising the coffee bed is to allow fine particles to adhere to the filter cup walls, making them less likely to fall to the bottom and clog the filter paper. This also creates better extraction channels for subsequent water additions!)

When the water in the filter cup is about to finish percolating, we use a gentle water flow to pour the remaining 75ml of hot water in small circular motions at the center of the filter cup. (The stirring force can be slightly reduced.)

Once the water in the filter cup has finished percolating, we can remove the filter cup to complete the extraction!

While this extraction method cannot make coffee taste as good as coffee within its flavor window, it can最大限度地 avoid over-extraction, preventing the release of undesirable bitter and other defect flavors in large quantities. If you already have beans that are no longer fresh, why not try brewing them using this method~

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Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

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