What is Coffee Bean Resting and How to Rest Coffee Beans: Beginner's Guide

Many customers who purchase coffee beans from FrontStreet Coffee's stores will ask about the specific roasting date after selecting their beans, showing that everyone has certain requirements for coffee freshness. However, FrontStreet Coffee wants to remind everyone that coffee beans are not necessarily better the fresher they are. In this article, FrontStreet Coffee will share some knowledge about coffee bean resting.

What does "resting beans" mean?

The packaged whole coffee beans we usually purchase are roasted beans that have undergone high-temperature roasting from green beans. Roasting causes coffee beans to expand and generates large amounts of carbon dioxide gas trapped inside the beans. Freshly roasted beans carry a roasting aroma with very active internal gases. If brewed at this time, when hot water is poured into the coffee grounds, the coffee won't have released enough gas during the blooming phase, affecting the extraction of flavor compounds in subsequent stages. In the later extraction stages, if the coffee bed is still bubbling and releasing gas, it will likely create turbulence, causing uneven extraction and ultimately affecting the coffee's flavor performance.

Therefore, roasted coffee beans need to rest for a period to allow most of the gas to be released gradually. As 60-70% of the gas is released, the coffee's flavor will gradually approach its peak, which is what we commonly call the "optimal tasting period." After this, the flavor will also gradually decrease as the gas slowly releases.

How long does resting usually take?

Degassing is a continuous process. If coffee beans completely release all their internal gas, it means they are no longer fresh, and naturally, there's almost no aroma left. So how do we determine the optimal resting period?

It's important to know that the darker the roast, the longer the heating time, and the more carbon dioxide contained in the coffee beans, thus requiring more time for degassing. This is especially true for dark roasted coffee beans that have undergone second crack, which have the maximum expansion and have accumulated large amounts of carbon dioxide gas. Therefore, when we store dark roasted coffee beans, as the resting time increases, the gas will cause the outer packaging to swell, indicating that the coffee beans are continuously releasing gas.

Taking the coffee beans sold by FrontStreet Coffee as an example, for medium-light roasted coffee beans, FrontStreet Coffee recommends resting for 4-7 days, while medium-dark roasted coffee beans require about 7-10 days to reach the flavor stability stage.

Can you brew coffee beans that haven't been properly rested?

After undergoing high-temperature roasting, coffee beans still retain some smoky flavors inside. Brewing coffee beans that haven't been properly rested will result in significant degassing during the extraction phase. The coffee is likely to have green, harsh flavors with unclear characteristics and a hazy, unclear texture. Therefore, FrontStreet Coffee believes that resting beans is very necessary. But what if you can't resist the urge to taste the coffee early?

FrontStreet Coffee has two small tricks for this situation. During the brewing process, blooming is the most important degassing phase. We can extend the blooming process to allow the coffee to release more carbon dioxide. For example, if our typical pouring process includes a 30-second bloom, we can extend it by 10 seconds, starting the second pour after 40 seconds instead. Another method is to grind the coffee and let it sit in the air for 1-2 minutes before brewing. Grinding increases the contact area between coffee and air, allowing more thorough gas release. It's worth noting that not only carbon dioxide is volatilized, but also small molecular gases that affect coffee flavor, which is why coffee needs to be brewed and consumed as soon as possible after grinding.

How should you rest beans?

After all this explanation from FrontStreet Coffee, actually, the coffee beans you receive don't require much operation. There's no need to open the bag and transfer to a sealed container, nor do they need refrigeration. Simply leave them in their original packaging in a cool, dry place. Coffee bags are equipped with one-way degassing valves. When coffee beans release gas, the packaging bag will swell. The function of the degassing valve is to prevent the coffee bag from bursting while maintaining pressure balance between the inside and outside. Then, after the recommended resting period, you can open the package and taste it. To ensure coffee freshness, FrontStreet Coffee ships coffee beans roasted within 5 days, typically arriving in 1-3 days. This way, the coffee beans everyone receives are close to their optimal tasting period, allowing you to start researching extraction methods.

Additionally, FrontStreet Coffee doesn't recommend squeezing coffee bags before opening them. Because when the gas inside the coffee bag is saturated, it will inhibit the rate at which coffee beans release gas, making the entire degassing process slower and thus helping to extend the tasting period. However, after manually squeezing out the gas inside, due to the pressure difference between inside and outside the bag, coffee beans will accelerate gas release to fill the space. The coffee aroma we smell when squeezing coffee bags is actually the loss of flavor compounds from the coffee beans.

For professional coffee knowledge exchange and more coffee bean information, please follow Coffee Workshop (WeChat public account: cafe_style).

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Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473