Instant coffee bears little resemblance in taste to freshly brewed coffee. It is commonly made with inferior ‘robusta’ beans. It is the product of a complex scientific process, yet we British love it.
It may be convenient, but do we actually know what we are drinking? Have you ever wondered how they make coffee soluble? After all, coffee is made using tough coffee beans that surely cannot be made to just dissolve in water.
The truth is that instant coffee does not contain any actual coffee beans; it is simply a dried coffee flavoured solution that is the product of a complex brewing process. This is how instant coffee is made, ready for the supermarket shelves.
The process starts by passing water through a series of cylinders full of ground coffee beans. Each of these cylinders is heated to a different temperature, and in at least one of the cylinders, pressure is applied to achieve a fuller extraction. One of the reasons why instant coffee is bitter is because, during this extraction process, the coffee grounds become burnt as they are exposed to temperatures of up to 180°C (the widely agreed optimum temperature, among coffee enthusiasts, to brew coffee at is between 90-95°C).
Filtration & Concentration:
This coffee solution is then filtered to remove any unwanted particles before the concentration stage. Here water is removed from the coffee solution to increase the flavour. There are several different techniques to do this, one of which involves heating the solution further to evaporate the water.
In this stage, the coffee solution is converted to a dry form. There are two commonly used methods; Spray drying and Freeze drying. The spray drying method is quite complex. However, the basic principle is to spray hot air through the coffee solution to evaporate the remaining water. Freeze drying involves quickly freezing the coffee solution into solid blocks, which are then broken up into small particles. These particles are then heated in a vacuum where the ice is vaporised and removed.
All these different stages and the high temperatures used in them, destroy most of the natural flavours that occur in coffee. The dry form of the coffee solution is, therefore, both stewed and bitter. So to help improve the taste, aromas produced during the various stages of this process are captured and then sprayed onto the dry coffee particles.