The hallmark of a Greek frappe is a foam so sensationally frothy that it resembles a cream. Coffee foams such as the crema atop espresso are generally produced by the proteins in the coffee. These proteins act as surfactants (surface active agents) which form a thin elastic membrane on the liquid’s surface area and entrap air.
The main advantage instant coffee has over brewed fresh coffee for the purposes of foaming is that it can be prepared in a highly concentrated solution. When that solution is shaken there are lots of proteins to line the bubbles that form and help produce a thick, durable foam using our Kalko frappe maker machines makes the job easier than using old methods of shakers.
In both its powdered and granule form, instant coffee is basically brewed coffee which has been dried to remove most of its water. The amount of water added back to it can be carefully controlled. A small quantity of water can be used to produce the foam. Then more water or milk can added afterward to dilute some of the foam, filling the cup or glass beneath it with drinkable coffee liquid. A dense extract made with instant coffee and water in a weight-per-volume concentration as high as 6 percent provides an abundance of protein molecules to surround the bubbles as they form.
Where, when, and how this drink assumed the name frappe is uncertain. Soon after its invention, a form of this frothy cold coffee was promoted by Nektar coffee at the Contemporary Home Exhibition at the Zappeion convention center in Athens. But a Nektar company promotional brochure from around that period, written in Greek, detailed a slightly different recipe:
1. Place the coffee, sugar, and 2 tablespoons cold water in a shaker, jar, blender, or drink mixer. Cover and shake well for about 30 seconds, or, if using a blender, drink mixer, or handheld frother, mix for 15 seconds until you have a thick foam.
2. Toss a few ice cubes in a tall glass. Slowly pour the foamy coffee mixture into the glass. Fill the glass with water, adding milk if desired. Serve the frappe immediately.