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:
- The coffee beans are ground-up.
- Softened hot water passes over the ground coffee beans, in order to eradicated unwanted gases.
- Cold water is then sent over the beans, in order to improve flavor.
- The solution is sent to filtration in order to increase the coffee concentration.
- The gases present in the mixture are altered yet again, in order to enhance the aroma and flavor.
- 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.