Should you find yourself in Greece on a hot summer’s day, a stop at an outdoor café makes a welcome break from sightseeing. While scoping out the premises, you’re apt to notice customers lingering over a frothy beverage that’s obviously some take on good old coffee. Should the concoction that’s caught your eye be foamy, light brown in color and served in a tall glass with a straw, the chances are good that the drink in question is a frappé.

The frappé is Greece’s cool-me-down beverage of choice, at once cooling and caffeinated. Its uniqueness lies not in its ingredients, which are absolutely commonplace, but in its method of preparation.

Just how the frappé became the country’s unofficial national drink is a fable from recent Greek history. At a trade fair held in Thessaloniki in 1957, a sales representative for Nestlé products by the name of Dimitrios Vakondios found himself without access to the hot water needed to have a cup of traditional coffee. So instead, he reached for a shaker meant for the Nesquick cocoa drink, filled it with coffee and cold water, and shook his beverage (along with himself), straight into the history books.

Most cafés in Greece these days have a special machine in the kitchen that makes the preparation of this drink a snap. But even without that whizzy appliance whose name no one seems to know for sure, your at-home version of the frappé will come together in minutes.

The list of ingredients needed to whip up a frappé is short and cheap: instant coffee, sugar, milk and ice. Here’s how it’s done:

Into a small glass jar with a screw-top lid, add 1 ½ to 2 teaspoons of instant coffee, along with a similar quantity of plain sugar, adjusting the proportions to your own preference. Nescafé is a commonly used brand, but far from your only option—any instant coffee will do just fine. Now add to the jar just a couple of ounces of chilled still water, tighten the lid, and give the mix a good shake. Continue to shake vigorously until you’ve created a jar full of luscious froth.

Next, pour the mixture into a tall glass. Add about three ice cubes. No doubt, there is still plenty of froth stuck to the sides of the jar, so continue to add small quantities of water and shake to remove as best you can. Keep adding the liquid to the glass until it reaches the brim.

Dairy lovers can at this point add milk of their chosen fat content; vegans can add almond milk or whatever non-dairy substitute they prefer. Those who don’t like any add-ins will enjoy the drink as is.

A frappé is typically served with a straw and a glass of water. When the drink is nearly finished, it’s common practice to pour a bit of water into one’s glass and stir, thereby loosening whatever foam has clung to the sides.

The frappé is so simple to whip up, it could easily be made at one’s place of work, assuming there’s access to ice cubes. And here’s a thought. Instead of heading off to your favorite on or off-base coffee establishment for a cooling coffee drink every hot summer afternoon, shake up this tasty homemade variation of the theme for pennies on the dollar at your desk or workspace. Slip three or so dollars into an envelope for every self-made beverage concocted and the expenses spared on an expensive, artificial ingredient-ridden, fancy shop-bought drink. By the end of the summer, count up the savings. With a bit of luck, there might be just enough in your envelope to purchase a flight to Greece on a budget airline. Plan your getaway for mid to late October, a time when northern Europe has already become unpleasantly cool, yet the southern reaches of the continent remain agreeably warm. Sit yourself down at the café or tavern of your choice and enjoy the frappé on its native soil. You’ll be glad you did.