Indirect Fired Air Heater Utilized in Instant Coffee Manufacturing


In the 1700s, the British invented instant coffee; the Japanese developed the first manufacturing technique over 150 years later. The creation of instant coffee allowed for easier storage and transportation due to a reduction in the product volume, as well as an increased shelf-life. As the demand for instant coffee increased, coffee manufactures began to devise their own manufacturing methods. Today there are two main manufacturing techniques: freeze-drying and spray-drying.

The taste of freeze dried instant coffee is more like that of a freshly brewed cup of coffee than spray dried coffee. However, because spray drying is quicker and a lot more cost efficient than freeze drying, the majority of store-bought instant coffee have been produced via spray dryer.

Below are the stages of instant coffee production using a spray dryer:

  1. The coffee beans are ground-up.
  2. Softened hot water passes over the ground coffee beans, in order to eradicated unwanted gases.
  3. Cold water is then sent over the beans, in order to improve flavor.
  4. The solution is sent to filtration in order to increase the coffee concentration.
  5. The gases present in the mixture are altered yet again, in order to enhance the aroma and flavor.
  6. The solution put through a spray dryer.

An indirect fired air heater is used as the spray dryer’s source of hot air in order to preserve the coffee’s flavor; indirect heating does not subject the mixture to the by-products of combustion, like a direct fired air heater.

After the dry particles are filtered by the cyclone, the instant coffee is packaged in a low-oxygen, low-humidity canister to optimize product flavor and consistency.