Instant coffee was invented in the 1700s but mass production methods were not developed until over 150 years later. There are two main production methods today - freeze drying and spray drying. Spray drying is more cost effective and quicker, though freeze drying yields a taste more similar to freshly brewed coffee. The spray drying process involves grinding coffee beans, passing hot water through to extract flavor, cooling, filtering, altering gases to enhance aroma and flavor, then spraying the solution into a dryer using indirectly heated air to evaporate water while preserving flavor.

1. Instant Coffee Manufacturing
Instant coffee was invented in the seventeen hundreds by the British. However, the first manufacturing
technique was developed over 150 years later by the Japanese. The primary reasons developing instant
coffee were: a reduction in the product volume would allow for easier storage and transportation,
increased shelf-life and preservation of excess coffee. As the demand for instant coffee increased, coffee
manufactures devised their own methods of instant coffee production. Today, there are two main
methods available: freeze-drying and spray-drying techniques.
Instant coffee made from freeze drying is a very intense process and requires more time and also capital
investment. However, the taste of freeze dried coffee is more like that of a freshly brewed cup of coffee
than spray dried coffee. However, spray drying is a lot more cost effective and quicker.
Production of instant coffee using spray drying begins with grinding the coffee beans and then passing
softened water through various hot columns of the ground beans. The mixing between this hot water
and ground coffee beans eradicates
unwanted gases and improves the flavor.
Next, the solution is cooled and then sent
to filtration to increase concentration.
Before going into the dehydration phase,
the gases present in the coffee mixture are
altered yet again, in order to enhance the
aroma and flavor.
Finally, the coffee solution is converted to
powder form by putting the product
through a spray dryer. From the image, you
can see that the coffee extract is subject to
air heated by an indirect gas fired air
heater, in order to evaporate the water. An
indirect air heater is used in order to
preserve the flavor of the solution, as
indirect heating does not subject the coffee
mixture to the products of combustion, like
a direct fired air heater. The dry coffee
particulates then collect at the bottom of
the chamber and are ready to be sprayed
even more with aromas and then sent to
packaging.

2. For more information on indirect heating of products, please visit Stelter & Brinck at
http://www.stelterbrinck.com/indirect-fired-air-heaters.htm or call 513-367-9300.
Keywords: indirect air heaters, coffee production, spray dryer, coffee flavoring, instant coffee
manufacturing, coffee beans