Now add enough cold water to just cover the coffee and sugar.
Place the lids (tightly!) on the jars and shake vigorously for around 30 seconds. You will be able to feel the solution change in texture.
When you have a creamy, frothy consistency, remove the lids.
Add lots of ice cubes (we add one full tray - 18 cubes - between two frappés).
Now add water and milk (if using) to taste.
Notes
As with all of our recipes, the calorie content in our Greek frappé recipe is approximate. It depends on how you prefer to drink your frappé.
Instant coffee is used over filter because this helps to create the froth.
The sugar and the coffee together create the creamy froth so if you have a sugar-free frappé, you won't get a thick, creamy froth.
For reference, the jars we use for our frappé are 450 millilitres. We fill them around half way with milk and water and let the froth reach the top of the jar.