The Secret of Coffee Bean Raising Period - Why do you need to raise coffee beans? How do you raise them? How long do you need to raise them?

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Can I drink the coffee beans right after they are roasted? Or how do I grow the coffee beans? How long does it take to grow them?

With the promotion of the specialty coffee market, many coffee lovers, including novices, have learned that coffee beans need to be nurtured before they taste good. But why do we need to nurture them? How do we nurture them? How long do we need to nurture them?

Before answering the above questions, let’s first talk about some knowledge about coffee roasting.

In fact, the scientific community has never stopped discussing the chemical substances in raw and roasted coffee beans. Even after investing so much time and money in research, the scientific community still has many questions about many details. According to current estimates, we can find at least a thousand different aromas in roasted coffee beans. Unfortunately, we still don’t know the exact number, and we don’t even know what the composition substances are. There are currently more than 200 unknown substances.

Each coffee bean contains about 200,000 independent cells, each of which is like a tiny pressure vessel, operating like a small reaction device. In the early stage of roasting, the moisture of the raw beans quickly dissipates, and the active water in the coffee begins to evaporate. As the temperature of the coffee beans increases, the evaporation of water will cause pressure on the cell walls. In this process, the element of water is the protagonist, and it undergoes a series of very interesting physical and chemical reactions with the oils in the coffee (so complicated that even science students want to bang their heads against the wall). As the pressure increases, the cell walls begin to swell, and the evaporation of water makes the cell walls slowly harden. As the roasting process continues, the internal pressure of the beans increases, and the coffee oils are brought into the tiny pores in the cell walls, creating a sealing effect that allows the cell walls to retain carbon dioxide, other aromatic substances and coffee aroma.

What is bean curd raising (awakening and maturation)?

Coffee beans are like living things. When people inhale oxygen, their cells oxidize, which is also a process of aging. Freshly roasted coffee is too immature and has not yet reached the most mature stage. Just like people, you will become more mature after years of growth. What you need is to give the coffee beans some time. To put it bluntly, bean cultivation is the process of "gas release", which is also commonly known as waking up the beans, raising the beans or maturing them.

Coffee beans that have just been roasted over a fierce fire contain about 2% carbon dioxide by weight, and this large amount of carbon dioxide is emitted along with the storage environment, equipment or method, making the pressure in the package higher than one atmosphere. The pressure helps the fusion of aromatic substances and oils, allowing all the aromatic substances inside the coffee beans to reach a state that is easy to be extracted.

The one-way exhaust valve commonly found in coffee bean bags on the market is used to discharge excess carbon dioxide to prevent the bean bag from being burst by carbon dioxide.

What does this have to do with packaging? This important question requires a peek into the mysteries of the cell wall structure in coffee beans. The cell walls in coffee beans are only about 5 microns thick, but they can withstand 140 psi (pounds per square inch) of pressure, and the main source of pressure comes from the carbon dioxide produced in the second half of the roasting process. Finally, a few days into the roasting cycle, the so-called outgassing process begins, and the carbon dioxide begins to escape from the coffee beans.

The exhaust process of the complete coffee beans is definitely much longer than the exhaust process of the ground coffee powder. The exhaust of the coffee beans will also shorten the life of the coffee beans. In the early exhaust process, air will replace the escaped carbon dioxide at a ratio of about 1:1. The air contains about 21% oxygen, so the absorption of air will quickly oxidize the coffee. The coffee continues to exhaust, the internal pressure of the coffee beans decreases, and the exhaust rate will begin to decrease. Over time, a 12-ounce bag of roasted beans can release more than half a cubic foot of carbon dioxide.

Why do we need to cultivate coffee beans? What effect does cultivating coffee beans have on their taste?

The flavor composition of roasted coffee beans is roughly determined. Many people attribute the change in flavor of coffee beans to the fact that the beans change every day. But as mentioned before, everything will deteriorate slightly after oxidation, affecting the taste. You may not have such a delicate taste sensation on apples, but you can clearly feel the change in taste of coffee.

Experiments have confirmed that the taste of coffee beans changes more in the first five days than in the next five days. This is mainly because the exhaust is most active in the first five days after roasting. Freshly roasted coffee beans release a large amount of aroma factors and carbon dioxide through the small holes on the beans that have been roasted. When they are ground, all the carbon dioxide escapes. During the brewing process, the powder is isolated from the contact with water, resulting in insufficient extraction (especially obvious in Espresso's high-pressure rapid extraction). As time goes by, the carbon dioxide gas layer becomes thinner and the contact area increases, and the coffee becomes more and more flavorful. Therefore, the coffee bean-raising period is not really "raising" the coffee beans, but a process of degassing and exhausting.

So, how to grow beans?

How to grow beans: Keep unopened coffee beans in a cool, dry, dark, and odor-free environment. After the bean growing period, cover the one-way exhaust valve (use transparent tape).

According to most experts, it is best to wait more than 6 hours for coffee extracted without a pressure device (such as hand-brewed coffee) (cupping requires 8-12 hours), and Espresso coffee requires more than 5 days.

The degassing of coffee beans only starts three hours after roasting. Coffee beans that do not release any carbon dioxide will have a very unstable taste after brewing. If you have ever poured hot water into freshly roasted and ground coffee powder, or used it to make a cup of espresso, you will find that the taste is very sharp and irritating, with over-extracted bitterness and obvious acidity. It will be difficult for you to associate it with the smooth and sweet taste.

So remember, in any case, time is absolutely necessary to allow the coffee to release carbon dioxide and stabilize the flavor.

If we let it sit until all the carbon dioxide disappears, wouldn't it smell really good?

Don't forget that aromatic factors are constantly lost over time. By that time, the coffee you brew may only have bitterness left, and the sourness and sweetness that should have been there have been lost. It is a better choice to grow the beans according to the degree of roasting or the roaster's advice. It is also recommended that the coffee beans at the bottom be shaken during the growing process to allow them to breathe upwards.

During the peak flavor period, the coffee beans may produce oil. This is actually normal, but it is also a small warning sign that the flavor of the coffee beans is about to decline rapidly, reminding you that you need to finish brewing quickly to avoid wasting the delicious coffee beans!

How long should it be kept? How to distinguish according to the degree of roasting?

There is no specific timetable for coffee bean cultivation. You can only follow experience or the advice of the roaster. Generally speaking, the deeper the roasting, the stronger the exhaust effect, the looser the coffee beans, and the faster the carbon dioxide is released.

Coffee beans extracted under normal pressure: The recommended curing time for very light roasted beans is 14 days; for light roasted beans, 10 days; for medium roasted beans, 7 days; and for medium-dark roasted beans, 4 to 5 days.

Italian coffee beans: Italian coffee beans are usually roasted to medium-dark roast or above, so they need to be aged for at least 5 days. About 10-15 days after roasting, the aromatic substances in the oil will become more stable, and the aroma and body of the brewed coffee will increase, and the stability will also be higher. However, commercial coffee beans usually do not have so much time to be aged, so they will be accelerated to wake up when exposed to air so that the coffee beans can reach the smooth stage as soon as possible.

The darker the roast, the more obvious the degassing effect (faster), and the faster the degassing is completed and the mature period is reached. The lighter the roast, the less obvious the degassing effect (slower), and the longer the mature period is.

The roasting method, technique or roasting degree of each bean is slightly different (for example, beans from a hot air roaster usually reach their best flavor period earlier), so there is no standard time for raising beans. It all depends on the user's understanding of the beans!

What is the best way to brew coffee at different growing stages?

To bring out the best flavor of coffee beans, you must calibrate and confirm the coffee grind size and adjust the amount of powder used. The longer the beans are stored, the more holes they will have. When you grind these coffee beans, they will be easier to break. At the same time, the exhaust reaction is weakened, making it easier for water to contact the coffee powder for extraction, and hot water can dissolve substances more easily.

Therefore, generally speaking, the longer the beans have been stored, the more careful you should be about over-extraction - you can try lowering the water temperature/coarsening the grind/reducing the extraction time/reducing stirring to achieve balanced extraction.