Instant coffee has been used for decades due to the fact that it’s convenient. In fact, these days, over 15% of the total coffee consumed in the US is prepared by mixing instant coffee granules with hot water in offices, at home and even in vending machines.
Manufacturing instant coffee starts with brewing coffee in efficient extraction. Then softened water will pass through five to eight columns of ground coffee beans. Once filtering is done, the brewed coffee will now be treated in one of the many ways in order for its concentration to increase. The goal here is to create 40% solid extract. In other cases, the liquid will be processed in a centrifuge in order for the lighter water to be separated from the heavier coffee extract. Another technique is to get rid of water through evaporation before the brewed extract cools. Other alternatives like cooling the extract to freeze water, separating the ice crystals from the concentrate.
In the several steps of the process of manufacturing coffee, the aromatic elements disappear. But they should be returned in the later step to create an attractive instant coffee. The aroma can be recovered in the several stages of the process. To preserve the aroma and flavor, oxygen must be removed first from the coffee extract. This is done by foaming other gases like nitrogen and carbon dioxide through the liquid before it gets into the dehydration phase of the entire process.
There are two basic methods used in converting the liquid coffee extract into its dry form. Spray drying is one of these and it can be done at higher temperature but this could affect the final product. However, it is cost efficient compared to freeze drying which is the second method of converting it into its dry form.
The aromatics that were recovered from the previous steps in the manufacturing process are sprayed into the dry particles of coffee. This can be accomplished in the packaging operation. Since instant coffee particles absorb moisture from the air, they must be packed under low humidity conditions in moisture proof container so that the product is kept dry until it is purchased and opened by people buying the product.