Three major hazards of improper storage of coffee beans. How to judge the freshness of coffee powder?

Freshness is the key to delicious coffee, so more and more people are getting used to buying freshly roasted coffee beans directly from roasteries. There are also many tips on how to identify fresh coffee beans. Today I will share with you the dangers of improper storage of coffee beans.

Effects of Improper Storage

In hot and humid climates, coffee is prone to mold growth due to improper temperature and humidity. Therefore, when storing coffee, the editor will explain to you the hazards of coffee beans after they are exposed to moisture.

Harm of coffee beans getting damp:

1. When exposed to moisture, the viscosity of coffee powder increases, which will clog the grinder of the coffee machine and have an adverse effect on the machine.

2. Once coffee beans are exposed to moisture, they will easily deteriorate and mold, which will greatly shorten their shelf life and is harmful to your health.

3. It will affect the taste of coffee drinks.

Therefore, the four most important factors in preserving coffee beans are "sunlight, oxygen, temperature, and humidity". The best storage method is to prevent coffee beans from coming into contact with these four factors.

How to judge the freshness of coffee beans? There are three steps: smell, look and peel.

Smell: Bring the coffee beans close to your nose and take a deep sniff to see if you can clearly smell the aroma of the coffee beans. If so, it means the coffee beans are fresh enough. On the contrary, if the aroma is weak or a greasy smell has begun to appear, it means that the coffee beans are no longer fresh.

Look: Pour the coffee beans into your hand and spread them out to determine the origin and variety of the coffee beans, and also to determine whether the coffee beans are roasted evenly.

Peeling: Take a coffee bean and try to peel it with your hands. If the coffee bean is fresh, it should be easy to peel it with a crisp sound and feeling. If the coffee bean is not fresh, you will find that it seems to take a lot of effort to peel a bean.

In addition, the most common one is: Are there enough bubbles when brewing?

The abundance of bubbles indicates freshness

Freshly roasted coffee beans contain a lot of gas and have vigorous respiration. When they are extracted, the gas in the beans is released, and what we see are beautiful and plump bubbles. There is a very vivid adjective to describe it, "blooming". Yes, when fresh coffee beans are extracted, clusters of rich bubbles are like flowers in this season, blooming.

Accompanying it is the rich aroma of fresh coffee beans.

A deeper look into whether bubbles are abundant or not

During extraction, the richness of bubbles is positively correlated with freshness. The fresher, the more bubbles. However, there is a premise here, that is, for the same coffee bean. To be precise, it is the same raw bean, the same roasting, and the same operation.

The richness of bubbles will vary between different coffee beans, or between different roasting degrees of the same coffee bean, or between different operating coefficients of the same coffee bean.

To summarize simply: for the same coffee bean, the fresher it is, the richer the bubbles; for the same coffee bean, dark roasted ones will produce richer bubbles than light roasted ones .

Different coffee beans, apart from differences in roasting degree and other factors, will also show differences in hydrophilicity from the perspective of their own structure, which is most intuitively reflected in the speed of water absorption and the degree of foaming.

Tips for Adjusting Extraction

For the same coffee bean, if the existing extraction method is not ideal, you can consider: increasing the amount of coffee powder, increasing the thickness of the powder layer, and increasing the time the coffee powder combines with water; increasing the extraction water temperature to further stimulate the activity of the coffee beans; reducing the degree of grinding, grinding the powder finer, and increasing the contact area between the coffee powder and water molecules.

Of course, the above suggestions are for fresh coffee beans.

Adjusting each extraction factor will have a certain impact on the final coffee taste. The final taste of the cup still depends on the maker's control.

Also, when we judge the freshness of coffee beans, we also need to consider whether the raw beans are fresh?

60% of a good cup of coffee depends on the quality of raw beans. As a coffee practitioner, you should open up your mind and learn as much as possible about the entire process from coffee seeds to cups, and build a coffee knowledge system. This will help you in the process you are engaged in. After all, roasters roast according to the properties of beans, while baristas brew according to the properties of beans and roasting concepts.

Different degrees of freshness of green beans

With the same bean variety, farm, altitude, and planting method, the dry and wet aromas of new green beans and old beans are very different. Because coffee is also a crop, freshness is very important for coffee.

Generally speaking, fresh coffee beans harvested in the current year are called "New Corp", those harvested the year before are called "Old Corp", and those stored for more than a year are called "Old Corp". This distinction is mainly due to the moisture content of the raw beans, because new beans have a high moisture content (usually between 11% and 13%) and are mostly dark green in appearance, while old beans (moisture content 10% to 11%) and old beans (moisture content 9% to 10%) are lighter in appearance green, lighter in weight and texture, and not as shiny and tactile as the surface of new beans. Of course, different processing and refining methods, origins, and varieties of raw beans will be different.

New beans: shiny and tactile like the surface

Changes in the freshness of green beans:

New season beans > out-of-season beans > old beans > aged beans

New season beans: green beans harvested within one year

Overdue beans: more than one year old. . . .

Old Bean: More than two years

Aged beans: mature green beans.

For example, after one year at room temperature, the moisture content of raw beans will drop below 10%. The color of freshly processed raw beans is blue-green/green, but as time goes by, the color of the raw beans will gradually turn into light green, white or yellow. And as the cooking time increases, the aroma of the raw beans will change from grassy and spicy to hay or rice. If it takes longer, it will have no taste at all.

The ripe "coffee cherry" is refined and processed into green beans through washing or drying. The moisture content is usually between 9% and 13%. It is not easy to roast if the moisture content is too high or too low.

Generally, the moisture content of newly harvested washed green beans is around 11.5% to 12.5%. Semi-washed Mandheling may reach 13%, semi-washed Brazil 11% to 12%, and sun-dried Mocha has a wider range of about 9% to 12%.

Coffee can be drunk all year round, but high-quality coffee also has seasonal issues. In fact, coffee is the same as fruit, with its own seasonal production period, and there are seasonal and out-of-season coffee.

However, there are at least 60 countries in the world's three continents that produce coffee, and the production seasons in the northern and southern hemispheres are different, which increases the complexity of this issue. Coffee lovers can learn about the seasons of each producing area and buy fresh beans more easily if they pay more attention to coffee.

When the rainy season in the coffee producing area begins is related to the harvest time. The rainy season prompts the coffee trees to bloom and bear fruit, which takes about 6-9 months. When the coffee berries are ripe and turn red, they can be picked and peeled, washed and fermented, semi-washed or sun-dried (the moisture content of shelled beans reaches 12%), and then put into warehouses for ripening for 1-3 months. Finally, the seed shells are ground off and they can be exported.

In other words, after the coffee beans are harvested, it takes at least another 2-3 months to complete the tedious post-processing before they can be exported.

Generally speaking,

• In the northern hemisphere, the Central American production area or Aceh in Indonesia is the busiest harvest and post-processing period from February to March each year, so the beans of the season can be shipped to consumer countries around May to October.

• Brazil in the southern hemisphere is the busiest harvesting and post-processing period from May to July each year, and seasonal beans can be shipped from September to April of the following year.

• The harvest season of fresh beans in Africa is from May to October, so the beans of the season can be shipped to consumer countries from January to March of the following year;

• Colombia has fresh coffee berries harvested all year round

• In addition, if the producing country crosses the equator, the production area is distributed in the northern and southern hemispheres. For example, Kenya has two harvest seasons, that is, fresh beans are exported in all seasons. Kona in Hawaii is from August to January of the following year.

• Vietnam, Thailand, and Yunnan generally harvest fresh fruit from November to January of the following year.

• Papua Guinea: April to September every year

• The harvest period of Jamaican Blue Mountain coffee is from June to November each year.

The flavor and aroma will last for different periods of time depending on the storage method.

No matter how good the quality of green beans is, they will be different due to different storage methods and storage facilities. The ideal is to maintain an indoor temperature of 15-18 degrees Celsius and an indoor humidity of 50%-60%. Wrong storage methods will affect the flavor and aroma of the beans, and even cause them to deteriorate. Often, the green beans will fade, turn white, and become soggy and soft.

White or yellow green beans: This is because the temperature in the storage place is too high or too dry, causing the moisture of the green beans to be absorbed by the air.

Green beans with wet surface: The humidity in the storage place is too high, and it is the rainy season. In serious cases, mold will appear on the surface of the beans.

5 tips for storing coffee

1. Refrigerate

Can coffee beans be put in the refrigerator? Yes. However, if you drink coffee beans frequently, you don’t need to put them in the refrigerator. Also, there are a lot of foods in the refrigerator, which can easily cause the flavor to taint.

Generally speaking, the best tasting period of coffee beans is two weeks, and they can be placed in a cool place indoors. If the coffee beans are in large packages, they can be divided into vacuum packaging bags when they are sure that there is no moisture in the coffee beans. This method can prevent the coffee beans from being affected by moisture when they are taken out for multiple uses, causing the coffee beans to deteriorate. Even if storing at low temperatures can extend the shelf life, it is still recommended to drink it as soon as possible to enjoy the delicious taste of the coffee itself.

If you open the frozen coffee beans right after taking them out, the temperature difference will cause moisture to condense on the surface, greatly damaging the quality! Therefore, do not open the packaged coffee beans after taking them out. Be sure to let them stand at room temperature for 1 to 2 hours to thaw, and then use them after they have cooled to room temperature.

Tips: A cool place refers to indoors. Coffee beans do not need to be refrigerated like fresh fruits and vegetables. Once taken out of the refrigerator, moisture will be generated. Do not put them in the refrigerator.

A little way to store coffee beans/powder is to divide them into portions and seal them in the refrigerator. If you put them in large bags and put them in the refrigerator, the temperature difference will form water droplets every time you take them out, which will have a great impact on the quality of the coffee. If you put them in small bags, just take out the amount you need to use each time.

2. Place in a dry environment

If the weather is hot and humid, the moisture-rich air will penetrate into the coffee beans, washing away the aromatic oils on the surface of the coffee and even producing a bad odor. Therefore, the coffee beans must be stored in a dry, cool place to prevent the beans from absorbing too much moisture or deteriorating due to high temperatures.

Coffee beans are afraid of heat (sunlight, heat source) and moisture. In fact, as long as you grasp the key points, the life of coffee beans will not say goodbye to you in advance: → Store in a "cool" and "dry" place (away from the sun. If you need to put it in a sealed can, choose an opaque material. Do not remove the original packaging of the coffee, but put the whole bag into the sealed can)

3. Exposure to large amounts of oxygen

Roasted coffee beans have less moisture content, so they are not easy to spoil. On the other hand, because coffee is a seed crop, it contains a relatively high content of fat. If it comes into contact with oxygen, it will start to sour and rot. Therefore, it is better to use a sealed container that can isolate oxygen. When storing coffee, the most important thing is to isolate it from light and external air. For this reason, most of the bags for coffee are coated with aluminum so that the bags can block air and prevent light from penetrating.

The best way to store coffee is to use tin cans. But if you go to most coffee shops, you will find that many stores use transparent sealed bottles to store coffee. This is based on display considerations, because the store must display the coffee to sell it. The coffee in this type of coffee shop is usually sold out quickly, so the possibility of producing bad taste due to improper storage can be said to be very small.

4. Grind into powder and store

It is not recommended to store coffee beans in the form of coffee powder. Even if the coffee beans are freshly roasted, once they are ground into powder, their contact surface with the air increases greatly, and they oxidize very quickly, and the freshness of the coffee will be lost immediately. Also, because the moisture content of coffee beans is low, they easily absorb moisture from the air, which leads to easy oxidation and corruption.

Therefore, the editor still recommends that you buy coffee beans on a regular basis. If the coffee beans have been ground into powder, drink them as soon as possible within the shelf life of two weeks.

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