How long can coffee beans be left after they are ground into powder? Why is it best not to pre-grind coffee beans? What's the difference between it and fresh coffee?

For many friends who make coffee at home, the bean grinder is not a must, so they often choose the grinding service of the merchant. After the coffee beans are ground into powder, the loss of flavor substances is greatly accelerated, which makes their taste period reduced to a certain extent. So the question is: how long will it take for coffee beans to taste after they are ground into powder?

In fact, at the beginning of last year, Qianjie did a special experiment to solve this problem. The general content of the experiment is: grind and seal a coffee powder at different time points, and then place it for a period of time to see how their flavor performance will change!

The results showed that the coffee powder stored in the sealed state at room temperature had a good flavor after 14 days and 21 days, but only the coffee powder stored for 30 days lost its flavor characteristics. Therefore, it can be concluded that after the coffee beans are ground into powder, the taste period is less than a month. You know, unground coffee beans can have the best taste period of up to two months, so why is the taste period cut by more than half after grinding?

Why is the rate of loss accelerated? Quite simply, the reason is that we often talk about a compound: "carbon dioxide". Coffee beans contain a lot of carbon dioxide after roasting! The existence of carbon dioxide can not only hinder the extraction of flavor substances by hot water, but also slow down the loss of flavor substances. When the coffee bean is a complete individual, because of its airtight structure, carbon dioxide can only be slowly lost. When we grind the coffee beans into powder, the bean table that could have "imprisoned" carbon dioxide is broken, and because of the substantial increase in the surface area of contact with the air, the loss rate of carbon dioxide has changed from slow to "surging".

When the carbon dioxide that hinders the loss of flavor substances is reduced, the loss of flavor substances will also be accelerated. Therefore, after the coffee beans are ground into powder, the taste period will be greatly shortened. But what needs to know is that what is lost is only the flavor substance of coffee, that is, the aroma, not its sweet, sour and bitter taste. Qianjie quoted a warm-hearted friend as saying: "Coffee still smells the same, but it's not as good as it used to be!" This is why Qianjie often advises friends to buy a small number of times, because only in this way can they drink a steady stream of fragrant coffee! Of course, even if the amount is small, the flavor loss of coffee powder will be accelerated due to the influence of some details when using it. So when we get the coffee powder from Daimo, we'd better pay attention to the following points!

First, the tightness of the packaging generally speaking, Qianjie will put a seal on the ground coffee bean bag (exhaust valve) to reduce the infiltration of oxygen and prolong the taste period. When we unseal the coffee powder, the sealing effect is weakened and air can pour into the beanbag in other ways. Therefore, Qianjie recommends that you can buy some vacuum sealed cans to reduce the loss of flavor substances by pumping air.

Second, the number of times and duration of opening the container every time we want to make coffee, we need to open the bean bag and take out the right amount of coffee powder! This operation will expose other coffee powder in the bag to a large amount of fresh oxygen, which will take away some of the flavor substances. The more times it is opened and the longer it lasts, the more flavor substances will be taken away.

Therefore, we'd better reduce the number of times and duration of opening! Immediately after weighing the coffee powder, seal the bag to reduce the time the coffee powder is exposed to the air, so that the flavor substances can be retained for a long time. Or you can divide the coffee powder into several containers, drink one serving at a time, and then open the next one. In this way, you don't have to worry that the coffee powder that has not been used will be affected because of the frequent opening times.

Third, whether the storage environment is coffee beans or coffee powder, it is best to store them in a cool and dry place. Because what they fear most is the hot and humid environment! High temperature will accelerate the volatilization of coffee aroma, moisture will make coffee powder easily damp and produce peculiar smell. Therefore, it is most suitable for the aroma retention of coffee powder to store coffee beans / powder in a cool and dry room temperature.

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