How should coffee beans be preserved and stored in a coffee shop?

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Storing coffee in vacuum-sealed packaging and in the refrigerator is generally considered safe-but not ideal. However, coffee stored in vacuum sealed packaging is allowed to age before packaging, so it is not at its peak freshness before it is frozen and must be as good as freshly roasted coffee after freezing.

It is not usually recommended that you keep open coffee bags in the refrigerator.

Instead, buy coffee when you need it, or store it in a dark room away from light, heat, moisture and odor.

However, there is some controversy about the argument that coffee should not be stored in the freezer, as described in the following more in-depth (reprinted) reader's question:

Problem: many coffee websites say I don't agree with several common propositions to store coffee in the freezer:

"the freezer is a damp place." The air in the freezer is dry. At-20 ℃, the vapor pressure of water or ice is much lower than at all warm temperatures. Allowing cold coffee to open in the kitchen may cause some condensation, but it may be stopped.

There is a smell in the freezer. Because of the low temperature, the steam pressure of the odor substance is low, so the freezer generally does not produce many odors (unlike refrigerators). However, the freezer is a closed space and coffee should be stored in a sealed container.

"freezing and thawing can damage the volatile oil necessary for the flavor of coffee." When stored at-20 degrees Celsius, essential volatile oils in coffee should be retained rather than evaporated, while low temperatures should inhibit the rate of oxidation that destroys molecules that are critical to aroma.

Can you provide additional information about these claims?

Answer: you have put forward some good points! This is why many coffee websites store coffee in the freezer:

Freezers are not always wet, but they get wet.

Although independent freezers cannot keep moisture, most refrigerator freezers have air transfer between the refrigerator and the refrigerator. Although the air is usually at the right temperature to prevent vapor from forming, opening and closing the freezer door (especially for longer when you arrive at the bag of summer berries at the very, very back) to introduce steam and change the temperature, the same is true of air transfer (albeit to a lesser extent) between the refrigerator and the freezer.

When the freezer gets wet and the coffee is not sealed, beans absorb water easily because they are hydrophilic (water-loving). When they do so, they can also suck the smell because...

The freezer smells.

The unique smell of "frozen burns" is a major example of refrigerators adding odors to frozen foods. As the Whirlpool website points out, "foods in refrigerators and freezers may lose their taste and even absorb the taste of other foods, such as fish and onions."

You may have to thoroughly clean the two food compartments to eliminate unnecessary odors. Be sure to wrap or store odorous food in airtight containers to control recurrent odors. "

Freezing and thawing coffee may damage essential oils.

Freezing and thawing food many times is hardly a good idea because it can affect flavor and aroma.

In addition, heating and cooling food repeatedly tends to introduce water into the food and then condense or evaporate according to the temperature. In Pu'er tea, the transition between hot and cold is desirable because it causes deep natural fermentation of the taste of the tea. This is different because the temperature range usually does not include freezing, but it is an example of how changing temperature can change the flavor and aroma of food or drink.

Freezing and thawing coffee may cause significant changes in the placement of oil and water in coffee and may cause the oil to move to the surface of beans during freezing and then dissipate when coffee is thawed.

However, the main problem with the freezing and thawing of coffee beans is that coffee beans are highly porous, and changes in temperature may redistribute water from the inside of the bag into the beans, adding unnecessary odors.