Find out about the five fresh coffee bean killers! Brand recommendation of fresh coffee beans on Taobao store

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The culprit that destroys the freshness of coffee:

● oxidation: the number one killer of fresh coffee beans

Fruit is easily oxidized after it is cut; similarly, coffee is easily oxidized after roasting. When coffee is roasted directly, it produces a large amount of carbon dioxide inside and outside the cell. this carbon dioxide is hidden inside and outside the cell, forming a protective layer, isolating oxygen and slowing down oxidation; however, with the passage of time, this carbon dioxide will gradually lose its function of protecting coffee.

At first, carbon dioxide is released very fast, and it slows down gradually after a few days; after about 10 days, it can release about 50% of carbon dioxide, and after 60 days, it will lose about 90%. The inside of the coffee bean will no longer be able to release carbon dioxide to protect itself.

Because carbon dioxide has the effect of antioxidation, we often see in some media reports that drinking coffee can prevent aging. Although this statement can not be proved, but the effect of drinking coffee can activate thinking has long been recognized by everyone.

It is also mentioned that after the coffee bean is ground, the cell wall will be completely destroyed, and the carbon dioxide will be completely lost within a few minutes, causing the coffee powder to undergo merciless oxidation. Therefore, grind coffee must be drunk as soon as possible! And this is also the reason why selected coffee stores only sell coffee beans and do not buy coffee powder, which is indeed reasonable.

● volatilization: the second killer of fresh coffee beans

After roasting, hundreds of new compounds occur inside the coffee beans to form aromas and flavors; some of these compounds are volatile and some are not. Unfortunately, the boiling point of good substances is very low, and these compounds are easily volatile.

Recently, the packaging technology of one-way breathable valve has emerged, which can make the carbon dioxide flow out of the bag without the inflow of oxygen, so it can keep the coffee fresh, which is called "fresh bag". Although its effect is good, the natural decay caused by volatilization can not be resisted.

● hydrolysis: the third killer of fresh coffee beans

Baked beans have a moisture content of less than 1%, and their pores are enlarged, making them easy to absorb moisture. Some people even put unused coffee beans in the refrigerator as a deodorant. After absorbing moisture, the interior of the coffee bean will be hydrolyzed.

The hydrolysis of organic compounds is very small, usually by acid or alkali to increase the rate of chemical change, but coffee beans contain a lot of acidic and alkaline substances (caffeine is a kind of alkaloid), therefore, hydrolysis is bound to occur.

The average relative humidity in South China is between 76 and 84, and the humidity in mountainous areas is higher, and the moisture content of coffee will rise to more than 12% in a short time, which has a significant negative impact.

● light damage: the fourth killer of fresh coffee beans

[light] is the catalytic role of catalysis, which can increase the rate of coffee oxidation and accelerate the deterioration of coffee. In some advanced countries, it can be found that their coffee bags are opaque, although they are quite aware of the destructiveness of light. However, in China, there are shops packing coffee in transparent plastic bags, and even in some high-end cafes, it is common to hold coffee beans in transparent sealed cans, but they do not realize that light will damage the quality of coffee beans.

● Oil: the fifth killer of fresh coffee beans

After baking at a high temperature, the oil inside the coffee beans will flow to the outlet of the cell pores, leaving a thin layer of oil on the surface. Lipids are the source of mellow flavor and should be cherished. However, after coffee beans have been stored for too long, the oil is easy to come into contact with water molecules, which can accelerate oxidation and cause corruption.

Oil is a sticky substance, out of oil for too long it is easy to condense coffee powder into blocks, in brewing, will hinder the infiltration of hot water, resulting in incomplete brewing phenomenon, and reduce the coffee should have powder flavor. Especially in brewing espresso, caking has a greater negative impact, which makes high-pressure hot water can not pass through the coffee powder, but only through the side slits, resulting in uneven brewing.

After understanding the internal changes of coffee beans, it is not difficult to find the following appropriate preservation methods:

● makes good use of the proportion of carbon dioxide

As far as gas is concerned, the specific gravity of carbon dioxide is higher than that of air. Therefore, in the same confined space, carbon dioxide will precipitate at the bottom, while air will float at the top. After understanding this truth, when you choose a container or bag, you can judge its applicability.

● uses vertical sealed cans

According to this reasoning, the carbon dioxide released by fresh coffee beans will be twisted at the bottom of the container to form an antioxidant layer to protect the coffee beans; and the container is best placed upright to prevent the loss of carbon dioxide in the jar or bag. Thus it can be seen that upright, tall and open containers are more suitable to protect coffee beans.

● uses long spoons to fish for coffee beans

The proportion of carbon dioxide is higher than that of air, so it will be deposited at the bottom of the container. When you take away coffee beans, remember to pour them out, otherwise the carbon dioxide in the container will be poured out and regeneration will become more and more difficult. It is suggested that the right thing to do is to use a long spoon and reach out to the bottom of the container to get the beans, so as to avoid the rapid loss of carbon dioxide.

● uses opaque jars

Light is the crude medium of oxidation, and opaque jars can slow down the rate of oxidation.

● uses vacuum cans

There are more and more vacuum cans on the market, and the price is also quite cheap. This kind of jar will be equipped with a mechanism, that is, by pulling or pressing, the air in the jar can be pumped out to form a vacuum. A vacuum indicates that there is no oxygen or moisture, which is a good place to store coffee beans.

Keep ● in a cool, dry place.

High temperature is easy to volatilize the aroma of coffee and the excellent substances inside coffee beans, so coffee cans should be avoided in high temperature environment, preferably in a cool and dry place.

● fresh coffee bean brand recommendation

Qianjie coffee freshly roasted single product-Italian fresh coffee beans: Yega Sheffield Coffee, Brazilian Coffee, Manning Coffee and so on are fully guaranteed in brand and quality, suitable for brewing with all kinds of utensils. And more importantly, the performance-to-price ratio is extremely high, a pack of half a pound 227 grams, the price is only 80-90 yuan. According to the calculation of 15 grams of powder per cup of hand-brewed coffee, 15 cups of coffee can be made in a bag, and each cup of coffee costs only about 6 yuan, which is very cost-effective for the normal price of 30 or 40 yuan a cup in a cafe.

Qianjie coffee: Guangzhou bakery, the store is small but a variety of beans, you can find a variety of unknown beans, but also provide online store services. Https://shop104210103.taobao.com