If you've ever looked at a coffee bag, you'll notice a button-like object on the back, which may have a few small holes in it, called an 'air valve'.
The purpose of this device is to allow carbon dioxide to escape from the bag, as freshly roasted coffee beans have to ventilate or, more appropriately, feel like they are breathing.
The valve is designed to help the beans expel the carbon dioxide, so in the case of coffee beans, it is a device that allows only air to flow out and not in, effectively slowing down the rate of aging of the beans.
Fresh coffee beans release carbon dioxide
During the roasting process, some of the carbon dioxides are released from the beans, but most of the carbon dioxide remains in the beans, so the beans will slowly release the gas inside for about two weeks after roasting.
If the bag containing the coffee beans does not have an air valve to assist with the venting process, the beans will continue to vent, and the bag will then become overstuffed. If the storage environment is cramped, the bag may burst, thus destroying the preservation of the coffee beans. (The bursting may take half a day or several days to be noticed, by which time the beans have deteriorated due to exposure to the air).
Air damage to coffee quality
As mentioned at the beginning, the air valve in the coffee bag is a one-way valve. The function of the valve is not only to remove gas from the coffee beans but also to prevent outside air from penetrating the bag and affecting the quality of the coffee beans.
To avoid damaging your health by over-consuming caffeine, please use a quick and free caffeine calculator to calculate your daily caffeine intake.
In another article, we mentioned the three main variables that affect the quality of coffee beans: oxygen, humidity, and temperature, which can shorten the optimum flavoring period of the beans and destroy their quality. This is why it is so important to get rid of internal gases without letting air in.
Squeezing a coffee bag to smell the aroma?
It is important to note that when the carbon dioxide is released, it also releases a lot of aromas from the beans, which is why we can smell a great aroma from the valve when we squeeze the bag. The air pressure inside the bag also helps to nourish the beans, and the squeezing action can also cause a loss of aroma and affect the quality of the coffee beans.
There are also different types of valves, so check with the shop for the type of valve used to maintain the freshness of your coffee. (Makoto uses the highest quality valves made in Italy to protect the quality of the coffee beans!)
To summarise the functions of the valves
1. Moisture-proof: it effectively keeps the coffee beans dry and full of flavour so that no moisture from the air can get into the bag.
2. Cushioning: When the coffee bag is transported and hit or dropped from a height, the air inside the bag can be discharged through the one-way exhaust valve, reducing the impact caused by the residual gas inside the bag and avoiding the bursting of the packaging.
3. Venting: After the coffee has been roasted, the carbon dioxide inside the bag can be effectively vented to avoid the bursting of the packaging.
Some of you may have experienced flying with coffee beans, and you may find that the bag is already dry when you get off the plane, like a vacuum rice pack. This can also affect the flavour and preservation of fresh coffee, as the cabin pressure squeezes the air out of the bag. Simply tape the air valve and place it in the zipped bag to give the beans an extra layer of protection.
Reactie plaatsen
Reacties