How Long is the Resting Period for Single-Origin Coffee Beans? How to Brew Pour-Over Coffee That's Too Fresh?

The Freshness of Coffee Beans

For roasted coffee beans, what FrontStreet Coffee refers to as freshness is the time elapsed after roasting. That is, freshly roasted coffee beans are at their freshest, and as time goes by, the freshness of coffee beans gradually decreases. After 2 months, the flavor of most coffee beans almost completely disappears, becoming stale.

In our daily understanding, stale coffee beans are certainly not good, but overly fresh coffee beans are not necessarily a good thing either.

The Freshness of Coffee Beans

FrontStreet Coffee believes that the so-called freshness of coffee beans actually depends on the amount of carbon dioxide within them. After roasting, coffee beans contain approximately 2% of their weight in carbon dioxide. This carbon dioxide slowly escapes from the beans over time. When carbon dioxide remains inside the beans, it inhibits the release of flavor compounds, helping to preserve the coffee's flavor.

When carbon dioxide begins to slowly release, it's essentially opening a gateway for flavor compounds. Some volatile aromatic substances escape along with the carbon dioxide, which is why when we see coffee bags puffed up, opening them reveals a very rich coffee aroma.

When almost all the carbon dioxide inside the coffee beans has been released, it means that some volatile flavor compounds in the coffee have also disappeared. Such coffee tastes less flavorful when brewed and might even develop off-flavors, indicating that the coffee's flavor period has ended.

Carbon Dioxide: A Double-Edged Sword

On one hand, carbon dioxide inside the beans can lock aromatic flavor compounds within them, preventing flavor loss. But on the other hand, carbon dioxide also hinders the release of coffee flavor compounds when brewing. Therefore, during coffee brewing, there's a blooming stage where a small amount of hot water is poured to release the gases from the coffee grounds. As the coffee grounds release gas, they expand and form a dome.

However, if the coffee beans are too fresh with abundant gas, during brewing, the blooming stage becomes overly active with carbon dioxide eagerly escaping, creating one or two large bubbles.

Furthermore, it's very likely that the blooming stage doesn't completely release all gases, and large bubbles continue to appear during subsequent water pouring, affecting extraction. Therefore, overly fresh coffee beans taste weak and lack fullness when brewed.

Dryness and Astringency

Freshly roasted coffee beans are very prone to dryness and astringency. Dryness refers to the uncomfortable, dry, and scratchy feeling in the throat after drinking coffee. This is because coffee beans have just been roasted, and the roasting aroma hasn't dissipated yet. This dryness in coffee beans only disappears after letting them rest for a few days, allowing the roasting aroma to dissipate naturally.

Sometimes, you can taste grassy and unripe fruit astringency in fresh coffee beans. This is not a roasting issue but rather because the gases inside the coffee beans are too vigorous. During blooming, the gases weren't completely released in time, affecting subsequent water extraction and causing under-extraction, which results in astringency.

How to Handle Freshly Roasted Coffee Beans

So how should freshly roasted coffee beans be handled? If you have coffee beans that are close to the roasting date, there's only one thing you need to do: resist the temptation and let the coffee beans rest undisturbed for several days. FrontStreet Coffee calls this process "bean aging" or "resting."

Freshly roasted coffee beans release about 60-70% of their gases after about 4-7 days. After that, gas emission becomes less urgent and occurs slowly in small amounts. After coffee beans rapidly release large amounts of gas within a week, they stabilize. This is when coffee flavor is at its best because volatile flavor compounds slowly dissipate after gas release, and when large amounts of carbon dioxide are released, the flavor compounds inside the beans are still abundant.

We can use the blooming process to release the remaining carbon dioxide, which will extract the flavor compounds from the coffee beans into the coffee.

How Long Should Coffee Beans Rest?

Taking FrontStreet Coffee's roasted beans as an example, light to medium roast coffee beans need about 4-7 days of resting. This means starting from the roasting date, waiting 4-7 days before tasting will yield better flavors. Medium to dark roast coffee beans require about 7-10 days to reach optimal flavor.

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473