Instant coffee

Instant coffee, instant coffee or instant coffee ( instant coffee from English ) is dried coffee extract. Created by pouring this powder with water immediately ( instantaneously ) a coffee drink.

History

Was invented instant coffee in 1901 by the Japanese scientists Satori Kato in Chicago. The foundation stone for the industrial production laid in 1938, the Swiss company Nestlé. Probably during the development the longer shelf life of the product over the conventional coffee in the foreground, because you wanted to counter a loss of value in rich harvest years. In addition, we found the preparation easier than regular coffee.

Production

First, the coffee beans are cleaned, free of debris, weighed and stored in silos, followed by roasting and grinding. Depending on the desired taste and aroma of a coffee blend coffees of different varieties ( Arabica or Robusta ) and the origin and quality are matched. Depending on the recipe, can this mixture be made either before roasting or she is given after each variety or provenance has been roasted for themselves. From the ground coffee, the freeness (approx. 2 mm ) is not comparable to that which is used in commercial coffee machines, the soluble components of the coffee are extracted in an extraction plant. Such extraction system uses water temperatures up to 200 ° C, for which a pressure up to 20 bar is necessary so that the water does not evaporate. The ground coffee is in so-called percolators, through which the hot water flows, thereby dissolving out the soluble components of the coffee. The coffee extract obtained is concentrated in an evaporation plant and dried. The coverage of such extraction plant is about ten times that of a standard household coffee maker.

The after extraction remaining coffee ground is generally burned for energy recovery for the extraction process in a steam boiler system.

Spray drying

In the spray drying of the coffee extract is pumped at high pressure into the upper part of a so-called atomizing spray tower. From flowing down a hot, dry air. The water of the extract is evaporated as it falls through the spray dryer, and in the lower part of the spray, the spray-dried instant goods collected. In spray -drying, a fine powder, soluble coffee is obtained. This takes place above all in soluble cappuccino use.

By agglomeration can it also generate larger metastable balls (diameter of several millimeters ) soluble coffee.

Freeze-drying

During freeze -drying of the coffee extract is first pressurized with air or CO2 ( foamed ), and cooled to about -5 ° C. This is comparable with soft ice cream product is then frozen in a freezer tape to about -50 ° C, then ground and sieved in a cold room. In a vacuum dryer, the water turned to ice is sublimated. The remaining solid component is the instant coffee.

Comparison between spray drying and freeze-drying

Starting from the same roast / roasted coffee extract obtained by the technically much more sophisticated freeze-drying a higher quality and flavorful their instant coffee than by spray drying, because of the freeze-drying, the thermal load of the extract is significantly lower than in the spray -drying.