Tips: How is instant coffee made?

Coffee is a popular drink all over the world, and nearly 300 million cups are consumed every day! The history of human coffee drinking can be traced back hundreds of years! But it is still very short compared to instant coffee! Instant coffee was not invented until the early 20th century, by a Japanese-American chemist. Therefore, the development process of instant coffee makes full use of chemical knowledge: the soluble substances in coffee beans are normally 40%, while commercial instant coffee can use some chemical methods to reach 60%!

Instant, convenient

How is instant coffee produced?

The traditional manufacturing method is to use spray drying (Spray Dryer SD): let the coffee liquid enter the drying chamber in a spraying manner, so that the water evaporates quickly to form a dry powder. However, since the drying effect is achieved by high-temperature heating during the processing, the aromatic substances of the coffee have already volatilized to a certain extent during the production process , so the instant coffee produced by this method is not strong enough. At the same time, the coffee powder produced by spray drying is too fine, and when the particle density is high, it is not easy to dissolve, which will cause certain troubles to consumers;

Another drying process can better preserve the original aroma and taste of coffee, giving consumers a better experience. That is freeze drying (Freeze Dryer FD): Instant coffee using freeze drying requires the ground coffee powder to be extracted and concentrated to retain the original flavor and aroma of the coffee as much as possible.

Freeze Dryer FD

The first step is, of course, the selection of raw beans. Generally, the Robusta variety is selected, which is not particularly flavorful and more affordable! The production method is the same as the common method, which is to select the raw beans first, remove impurities, and then roast, mix, extract, freeze-dry, grind into powder, etc. But the post-processing will be very different!

First, the raw beans are roasted. Of course, it is not the roasting machine in the coffee shop, but a purely industrial large machine! Although there are computers to control the temperature and even manual supervision, they are all standardized operations and basically will not be fine-tuned according to specific circumstances!

Large machine baking

The grinder grinds the coffee beans into a coarse powder

In the super-large coffee machine, the flavor of the coffee powder is squeezed out by hot steam under high pressure. Every hour, 18,000 liters of coffee can be squeezed out. The extracted coffee substance will be continuously heated, and the process is a bit like making syrup, and it looks a bit like chocolate sauce.

Espresso Liquid

Then comes the next step: freezing! To ensure the taste of the coffee, it must be cooled quickly, at a temperature of minus 40 to 50 degrees Celsius. When it is cooled, it will be crushed into very small particles using a crushing device. The temperature in the freezer reaches minus 50 degrees Celsius, and workers must wear thermal clothing to enter. The espresso on the conveyor belt will be frozen into ice cubes during transportation.

Rapid freezing process

At the end of the conveyor belt, the frozen coffee will be crushed. But the coffee frozen into ice cubes still contains water. To make instant coffee, you need to remove this water, but if you let the coffee ice melt, the aroma will be lost. How can you remove the water without letting the coffee ice melt? The solution is to put the coffee ice cubes into trays, pile them up, and then stay in a low-pressure pipe for 5 hours. Heated to 60 degrees in the vacuum environment of the pipe, the water will sublime directly from solid to gas under pressure.

When the coffee in the tray comes out of the pipe, it has become frozen but dry coffee powder. The aroma will be locked and will not be lost at room temperature. This is the core of freeze-dried coffee production. However, due to the high cost of low-temperature freezing and vacuum heating equipment, some low-quality instant coffee will use spray drying and flavoring methods. Then the tray will be rotated and the coffee powder will be poured into bags for packaging.

The glass container passes through a conveyor belt and a bottle of coffee is filled in less than a second.

The lid is then tightened and the product is labeled on its way to the factory exit.

This is the instant coffee we usually drink, but it is the pure instant coffee without the addition of coffee companion. However, no matter how advanced the processing procedures are, under the current technical level, the aroma of instant coffee will still be lost. But those who are heavily dependent on caffeine don't have to worry, the caffeine in instant coffee will not be reduced.