Preparation
The coffee can be made either with a cocktail shaker or an appropriate mixer (e.g. a hand mixer). One or two teaspoons of coffee, sugar (to taste) and a little water are blended to form a foam, which is poured into a tall glass. To this is added cold water and ice cubes, and, optionally, milk - typically evaporated milk. The glass is served with a drinking straw.
Icecubes
An essential part of Frappé are the icecubes. Apart from keeping the coffee cold for more time, they are part of the culture of Frappé. While there are icecubes in the coffee, one rotates the drinking straw, mixing cold water near the icecubes with less cold water at the bottom and further mixing the foam (that contains coffee) with the water. While the drinking straw is rotated along a circle near the border of the glass, the icecubes hit with each other and with the glass, producing a sound characteristic of the Frappé. Mixing the coffee and listening to the sound most of the time has a pleasing effect and is the most common reaction among people drinking Frappé.
Frothy top
The spray-dried instant coffee contains nearly no oil, just tiny particles (coffee solids), some molecules responsible for flavor and taste, and of course caffeine. When dissolved, spray-dried coffee forms a simpler and more stable colloid relative to traditionally brewed coffee. This enables creation of the characteristic thick frothy layer at the top of the coffee. This layer appears similar to crema, the foam found in espresso, but is much thicker and the composition is different. It can be characterized mainly as a three phase colloid where tiny bubbles are held together by the coffee solids.
