Coffee is often served in a cup with a small saucer underneath. It is not a simple support and we know what it is really used for.
France is one of the major consumers of coffee. According to a study from the Ipsos polling institute for Nescafé, which surveyed 1,000 French people in spring 2024, 86% of them consume it, including 73% on a regular basis with 53% having an average of three cups per day. The French like to have a cup of coffee at home, especially at breakfast (73%). That being said, they also enjoy going to a café from time to time to enjoy this hot drink (14%).
In these spaces, coffee is often not served alone. It can be accompanied by a glass of water. This allows you to cleanse the palate and prepare yourself to receive the aromas of coffee. Water helps to rehydrate compared to a drink with diuretic properties.
Another custom is to serve it with a small cake or sugar, placed on a saucer. The sugar comes with a spoon so you can mix. If this small plate serves, in fact, to support the cup as well as the spoon or the treats, this is in reality not its primary purpose.
Originally, the cups did not have handles. The saucers were then used to collect the small drops that could escape from this container. This quickly evolved into a second use, useful even once the cup had a handle: cooling the coffee. By placing the coffee on the saucer, the contact surface with the ambient air increases and the heat of the drink dissipates more quickly. A current of cool air circulates between the cup and the saucer and this convection lowers the temperature of the drink.
Your coffee, if it is served to you too hot, will therefore cool more quickly and you will be able to enjoy it at the right temperature without waiting too long and without burning yourself. This also protects the place where the cup is placed from the heat.
In the 18th century, it was sometimes even customary to pour hot drinks directly into the saucer to cool them more quickly. They then often had fairly high edges. Today, we would no longer see ourselves resorting to such a gesture in public.