Essuyer les plâtres

Imagine your friend invited you for dinner and wants you to try her new, experimental dish. She jokes, "You're about to essuyer les plâtres of my latest culinary creation. Bon appétit!"

Intrigued, you take a bite and suddenly realize why you are "wiping the plasters."  It turns out your friend's experiment was a bit too experimental. The flavors clash, leaving you to ponder whether the dish was designed to be eaten or used as a paint remover.  That's what the expression is about:  Essuyer les plâtres means to be the first to try something, to be the guinea pig.

The expression carries a sense of risk, as the person or group "essuyant les plâtres" may encounter difficulties or setbacks that subsequent participants can learn from and avoid. Therefore, the idiom is often used to describe individuals or groups who undergo the initial challenges, problems, or learning curves associated with a new endeavor.

Origin

The expression was born in the 18th century, in the feverish outbreak of urban construction under Louis XVI, when many French cities - and Paris in particular - doubled their surface areas. In 1783, Louis-Sébastien Mercier exposed the disadvantages of these new houses: "The plasters that are used in the construction of these houses do a lot of harm, because they dry with difficulty."

He then reveals a somewhat surprising custom which casts a strange light on these new dwellings: “We abandon these new and damp houses to the prostitutes."  The poor women were offered free lodging while the plasters were drying - a process that could take several weeks.  They were then kicked out of the house so that the owners could safely move in.

Author Théophile Gautier, later evoking these practices of the Ancien Régime, confirmed the nickname of  “plaster wipers” given to the unfortunate women who were allowed to stay in the newly built houses of the bourgeoisie until plasters were dry.

This infamous origin kept the expression away from dictionaries until 1850, and even then, it only entered dictionaries in the "very familiar" register.  Today, however, the expression can be used in any context.

Examples

Maintenant que nous avons essuyé les plâtres avec ce nouveau logiciel, nous pouvons enfin faire un lancement officiel!
Now that we've had our hands full with this new software, we can finally do an official launch!

Quand on lance un nouveau projet, il faut souvent se donner un peu de temps pour essuyer les plâtres.  C'est rare que tout marche du premier coup!
When you start a new project, you often have to give yourself a little time to get the hang of it. Things rarely work right away!