One of the best ways of preserving the taste of coffee is the Freeze-Dried Coffee method. More of the volatile oils remain in the product giving it that “real” cup of brewed coffee flavor.
Invented in 1901 by a Japanese scientist by the name of Satori Kato it was later marketed around 1920 by George C.L. Washington. Nescafe was developed 18 years later in 1938, the first name brand on the market.
Post WWII America saw the advent of instant coffee and since then freeze-drying has grown in popularity as it is a higher-quality product and more expensive.
The method of making freeze-dried coffee involves brewing large vats of coffee and placing them through evaporators making highly concentrated liquid.
To preserve the aroma and flavor “foaming” gases are infused through the coffee removing oxygen. The wet coffee granules are then rapidly frozen and placed in a drying chamber on metal trays.
The frozen coffee is ground into particles and the ice crystals are then removed by sublimation meaning transference from a solid state to a gaseous state without the liquification phase. A vacuum is created in the chamber is warmed, usually by radiation.
The frozen water in the coffee granules expands to ten times its size and is removed as vapor from the chamber. Volatile aromas are sprayed on the coffee granules.
The product is then packaged in a low-humidity, low-oxygen environment to maintain its integrity. The process is environmentally friendly.
The advantage of freeze-dried coffee is that it is portable and can be taken anywhere and mixed with hot water gives you a nice fresh tasting cup of coffee.