Coffee beans are so slender: does it taste better when frozen, or does it change when frozen?

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From time to time, people will ask: can coffee beans be kept in the refrigerator? In general, the answer we get is "it is not recommended to save in this way". However, this does not mean that no one is studying how to freeze coffee beans.

Is it really not recommended to keep coffee beans in the refrigerator?

Coffee beans are a very delicate thing, and sunlight, air and moisture are all enemies that affect its preservation. After roasting, the freshness of coffee beans will be greatly reduced and begin to deteriorate. Especially after grinding, the aroma begins to weaken and the taste will go away. The storage environment of coffee beans directly affects its ripening time, the ripening time is fast when the environmental temperature is high, the ripening time is short, the ripening time is slow when the environmental temperature is low, and the longer the ripening time is.

Isn't the refrigerator with low temperature and low humidity suitable for preserving coffee beans?

In fact, the coffee bean itself is easy to absorb external taste and water vapor, so if you do not use a sealed container that can block the external air, the coffee bean will have a bad smell. This is the principle that some common sense of life recommend using expired coffee beans to help the refrigerator absorb flavor.

And when the coffee beans are taken out of the refrigerator, the surface of the temperature difference between the coffee beans and the surrounding environment will begin to condense water vapor. When the coffee beans absorb the water vapor, they will become soft and stale.

Therefore, for the preservation of coffee beans, it is more recommended to put them in a sealed container at room temperature, as long as you avoid direct sunlight.

Then why is there the practice of freezing coffee beans?

The reason why so many coffee beans can't be stored in the refrigerator is mentioned above, but in reality, the practice of freezing coffee beans still exists.

In the top coffee competition in Australia, some contestants use dry ice to grind and brew the coffee beans. This practice takes advantage of the phenomenon of "glass transition". Simply put, frozen coffee beans become more crisp and easier to grind. At this time, the size of the ground coffee powder is more uniform, which is more helpful for the follow-up coffee extraction.

Since there is such an advantage, it is better to put the coffee beans into the bean grinder after falling to a few degrees. According to scientific research, the colder the better. Coffee beans are ground and boiled in three different ways: frozen (- 19 degrees Celsius), dry ice (- 79 degrees Celsius) and liquid nitrogen (- 196 degrees Celsius). The flavor of coffee beans is better than that of room temperature coffee beans.

In the final analysis, this is all an exploration of the flavor of coffee.

At present, there are few studies on coffee cryopreservation. Expensive freezing costs and harsh conditions make this way of pursuing a better flavor of coffee lack the practical significance of popularity.

But scientists and some coffee lovers are still working on it, hoping to keep some expensive coffee beans longer and store them in freezers in vacuum packaging.

Would it be cool if you were in a coffee shop one day and saw the barista take a cup of vacuum-packed coffee beans out of the freezer?