How Is Instant Coffee Produced?
As a saying goes, Laziness serves as the main driver of scientific and technological progress. When it comes to diet, many people are also in the pursuit of a convenient way. Take coffee as an example, it’s too troublesome for one to have beans ground into powder and boiled every time when making coffee. So instant coffee is produced, which is considered as a gift from God to lazy people. As long as you open the bag, pour it into a cup, and add some hot water, you can enjoy a cup of delicious coffee. But how is instant coffee produced? Today, we will introduce instant coffee made with the freeze-drying method.
Coffee beans from South America will be sent to a silo outside the factory for storage. Nearly 560 tons of beans can be stored. Then the beans were sent to the oven and baked at 200 degrees. Then the beans will be constantly stirred to prevent local temperatures from being too high.
After the first step, the beans will be ground into a coarse powder. In the super large coffee machine, the flavor of the powder is squeezed out by hot steam under high pressure. 18000 liters of coffee can be squeezed out per hour. After that, the coffee will be heated and extracted until it is concentrated into essence, and then sent to the freezing bin by a conveyor belt.
The temperature inside the freezing bin should reach minus 50 ℃, and in order to retain the aroma of the coffee, the next step of extracting coffee must be carried out under the icy condition, at least minus 40 degrees. Coffee on the conveyor belt will be frozen into ice during transportation. At the end of the belt, frozen coffee will be crushed. However, this kind of coffee still contains water, which needs to be removed to make instant coffee, but if the coffee ice melts, the aroma will be lost.
How can the moisture be removed without melting the coffee ice? The solution is to put the coffee ice cubes into a tray, pile them up, and then let them stay in a low-pressure pipe for five hours. When heated to 60 ℃ in the vacuum environment of the pipeline, water will sublimate directly from solid to gas under pressure. As the coffee in the tray comes out of the pipe, it has become frozen but dry coffee powder. The aroma will be retained at room temperature, which is the core of freeze-dried coffee production.
The tray will be rotated and the coffee powder will be poured into bags for packaging. The glass container will pass through the conveyor belt and can be filled with a bottle of coffee in less than a second. After that, the lid will be tightly closed and labeled. An average factory can produce 420 tons of instant coffee each week.
However, no matter how advanced the processing process is, under the current technological level, the aroma of instant coffee will be a bit less. But coffee fans don’t have to worry. The caffeine in instant coffee won’t decrease. （Tip: You can also make instant coffee at home.）