How long can coffee beans last after being ground into powder? How to store coffee beans after being ground?

The flavor of coffee mainly comes from the aroma substances produced by roasting raw beans, and most of the aromas are volatile. So if we want to feel the fragrance from the coffee, then it is best to choose freshly roasted freshly ground coffee, which is often mentioned in front of the street. Because the structure of coffee beans is very complete before grinding, the aroma can only slowly flow out from the surface of coffee beans, once the coffee beans are ground into powder, then the increase of nearly a thousand times the surface area will greatly accelerate the loss of flavor of coffee beans. Even when properly stored, the taste period of coffee powder is less than half that of coffee beans.

A month ago, the street shared such an article about how long the coffee beans will be tasted when they are properly stored after they are ground. Then a friend left a message in the comment area, wanting to know how the aroma of coffee powder would change in a short period of time without a seal. So today in front of the street to experiment, different periods of time grinding coffee powder made of coffee will have what kind of difference! In other words, how long can the coffee beans be kept unsealed after being ground?

Coffee experiment in order to ensure the rigor of the experiment, but also to reduce human interference, the front street of this experiment will first make and evaluate coffee in the form of cup test. The coffee beans used this time are still the rosy summer of Poquet in Panama, and the traditional washing treatment will have a cleaner performance and better show the difference that time brings to coffee. Qianjie grinded 12g coffee powder 2 hours ago, 1 hour ago, 30 minutes ago, 10 minutes ago, and now put it into a cup test bowl. Then we first smell the incense and feel the difference in the aroma of five pieces of coffee powder ground at different times.

There is not much difference in aroma between the coffee powder now ground and the coffee powder ground 10 minutes ago. You can smell rich aromas of flowers, citrus and berries. Although the coffee powder ground in front can smell the same aroma performance, but relatively speaking, their aroma is not so strong, the more the faint. In particular, the coffee powder ground 2 hours ago has aroma, but it smells more of the coffee itself. After the smell is over, we can start making coffee. According to the process, we fill the cup with hot water of 200ml94 °C according to the ratio of powder to water of 1 16.66, then press the timing button synchronously and wait for 4 minutes.

4 minutes later, take out a spoon to break the dregs, pick up the dregs, remove the dregs that hinder the mouth, and then you can start tasting the coffee.

The result is not unexpected, which is consistent with the experience we feel when we smell incense. The coffee ground now has the same performance as the coffee ground 10 minutes ago, and the flavor is outstanding and clear, while the earlier the coffee is ground, the weaker the flavor. In particular, the coffee ground two hours ago, not only does not have a prominent aroma, but also feels a little empty (very insipid). We can basically see the difference from here, but it is not enough. Qianjie specially reserved a portion of coffee powder ground two hours ago to make a pot of hand-brewed coffee with the currently ground coffee powder, and then compare it again. Because hand-brewed coffee allows us to more intuitively see and drink the gap between the two. The extraction parameters are as follows: the amount of powder is 15g, the ratio of powder to water is 1:15, the water temperature is 92 °C, the grinding scale is 10 °Ek43, the cooking method is three-stage cooking, and the filter cup is V60.

In terms of steaming, we can see that although the parameters are the same, the coffee powder ground 2 hours ago not only failed to bulge a large "powder bag", but even sunken down (the one on the right). At the same time, the "water locking effect" of the powder bag is not as good as the freshly ground coffee. This is the effect of carbon dioxide loss caused by pre-grinding. In addition to the different degrees of drum bags, in the brewing process, coffee ground 2 hours ago will be faster to enter the water, so its extraction time is relatively short, 1 minute 50 seconds, while the current ground coffee powder is 2 minutes 01 seconds.

The difference in taste is more direct. The flavor of the pot of Rosa boiled now has the aroma of white flowers, citrus, berries and honey, with rich layers and outstanding flavor. In contrast, the coffee ground two hours ago, its flavor performance is only a little sour berries, a hint of flowers, the rest can only feel the sense of tea, as measured by the cup, very monotonous. To sum up, we can know that if the coffee beans are not sealed or boiled immediately after grinding, the aroma will almost escape as long as they are exposed to the air for about two hours. Therefore, if we can not use the coffee beans quickly after grinding them into powder, it is best to use the lid to seal the mouth of the powder bowl so as to reduce the air contact with the coffee powder and reduce the loss of aroma.

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