Frappé coffee (also Greek frappé or Café frappé) (Greek: φραπές, frapés) is a Greek foam-covered iced coffee drink made from instant coffee (generally, spray-dried). It is very popular in Greece and Cyprus, especially during the summer, but has now spread to other countries. Accidentally invented in 1957 in the city of Thessaloniki, it is now the most popular coffee among Greek youth and foreign tourists. The frappé has become a hallmark of the post-war outdoor Greek coffee culture.
The word frappé is French and comes from the verb frapper which means to 'beat'; in this context, however, in French, when describing a drink, the word frappé means chilled, as with ice cubes in a shaker. "Café Frappé" originated in France probably in the last decades of the 19th Century, and as early as 1897 the term is used for a sort of coffee granita, and another mention is from 1932, where caffè frappé is indeed an iced coffee: 
Note that the term caffè frappé, while used in Italy, is a mishmash of Italian (caffè) and French (frappé). The correct French spelling is café frappé.
Greek frappé was invented in 1957 at the International Trade Fair in Thessaloniki. The representative of the Nestlé company, Yannis Dritsas, was exhibiting a new product for children, a chocolate beverage produced instantly by mixing it with milk and shaking it in a shaker. Dritsas' employee Dimitris Vakondios was looking for a way to have his usual instant coffee during his break but he could not find any hot water, so he mixed the coffee with cold water and ice cubes in a shaker. This improvised experiment established this popular Greek beverage. Frappé has been marketed chiefly by Nestlé and is among the most popular drinks in Greece, and has been called the national coffee of Greece, and is available at virtually all Greek cafés.
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.
Frothy top 
The spray-dried instant coffee contains nearly no oil, just tiny particles (coffee solids), some molecules responsible for flavor and taste, and 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.
The absence of oil (or the significantly lower oil content compared to traditionally brewed coffee) makes the system more stable and the bubbles do not collapse with the same ease as in crema. Soon after the foam is created, a process of thickening takes place where water molecules are constantly pushed out of the frothy mixture. The water is pushed out due to drainage occurring due to pressure differentials along the foam septum. Higher viscosity will retard the phenomenon, and that is the reason that the addition of sugar will create a better foam. The phenomenon continues until bubbles come very close together and the foam almost solidifies. This process can take between 2 minutes to 10 minutes and depends strongly on the agitation process during mixing. As the bubbles come closer together they will slowly start to coalesce and create bigger bubbles. According to the Laplace equation, variation in bubble size will result in faster collapsing of the bubbles since the bigger bubbles will consume the smaller ones. Hand-mixers create smaller and more uniformly sized bubbles. The smaller bubble size reduces the bubble pressure gradient and forms a much longer lasting foam.
The presence of oil (a hydrophobic agent) can significantly accelerate the collapsing process localized reduction in the foam elasticity, resulting in the creation of a lighter foam with average bubble diameter larger than 4 mm. This is the reason it is not possible to make a good frappé in many countries, unless one can find spray-dried coffee (which is actually generally less expensive than freeze-dried instant coffee). The utilization of a hand mixer makes possible the creation of finer bubbles which increases the time that the foam can last. The best frappé coffees are often held to be those with the smallest bubbles and a thickness of about 1.5 inches to 2 inches (30 mm to 50 mm) of foam.
Greek Frappé variations 
Frappé is in Greece available in three degrees of sweetness, determined by the amount of sugar used. These are: glykós (γλυκός, pronounced [ɣliˈkos], "sweet", 2 teaspoons of coffee and 4 teaspoons of sugar); métrios (μέτριος, "medium", 2 teaspoons of coffee and 2 teaspoons of sugar); and a skétos (σκέτος, "plain", 2 teaspoons of coffee and no sugar). All varieties may be served with evaporated milk (με γάλα Greek pronunciation: [me ˈɣala]), in which case they may be called in slang φραπόγαλο (frapógalo, Greek pronunciation: [fraˈpoɣalo], "frappé-milk"), or without. Sometimes, frappé is served without any water (besides the water used in the foam) and milk is used instead. This variation is most commonly found in Cyprus.
Kahlúa, Baileys Irish Cream or other liqueurs are sometimes used for additional variation, as well as chocolate milk. Many restaurants add a ball of vanilla ice-cream into their frappe instead of milk. Though not technically "frappé" (since they are not shaken), some variations are stirred with a spoon, creating a slightly different texture and, according to some, taste.
Frappé outside Greece 
Although a Café Frappé today mostly is associated with the Greek instant coffee version, the rest of the world have during the last two decades embraced the espresso version, simply shaking a double espresso with 1/2 teaspoon white sugar (shaker 2/3 full of ice) and poured directly into a glass. Greek Frappé is also consumed in Cyprus, where the Greek Cypriots adopted the frappé into their culture, in Albania, the Republic of Macedonia, Thailand, Malaysia, Indonesia, parts of Turkey, Ukraine, Poland and Romania. In recent years foreign tourists in Greece have taken frappé to their homelands, where it has been adopted with some differences. In Bulgaria, Coca-cola is sometimes used instead of water (possibly the inspiration for Coca-Cola Blāk), in Denmark, cold milk is often used instead of tap water. In Serbia, frappé (usually called hladan nes, "cold instant coffee") is usually made with milk or ice-cream, and whipped cream is often added on top.
In the United States, a frappé is an iced coffee drink, either sold chilled or frozen. The frozen variant is similar to a smoothie while the chilled formulation is most associated with Starbucks' Frappuccino. The Starbucks in Greece offers both Frappuccino and Greek-style "Frappe" (written by Starbucks without the accent).
- Mabbett, Terry. "Greece in an Instant (Tea & Coffee Trade Journal, October 2007)". Retrieved 2009-10-24.
- :The Milwaukee Journal", July 9, 1897, full text
- "Coffee Frappe". Southeast Missourian. Retrieved 2010-09-25. Unknown parameter
- 1957 International Trade Fair in Thessaloniki)
- Mabbett - page 2