PARIS — It’s hard to imagine a country where butter is taken more seriously than it is in France.

It’s a staple of sauces and baking, alike. Without it, the croissant would be a leaden mass of flour, and the jambon-beurre sandwich missing a certain something. The Rouen Cathedral is said to have been built in part on the back of butter fees, and even today, in the western region of Brittany, salted butter is something of a religion.

So an empty butter shelf in France is like a dry baguette: deeply disconcerting.

But with a slump in European dairy production and a surge in world demand, that is exactly what some French are encountering in their stores.

Alarmed by news reports about the shortage, Laurence Meyre, a 53-year-old professor shopping in a supermarket in southern Paris one recent morning, said she had made sure to stock up. “I thought to myself: Not having butter in France, that’s appalling,” she said.

In truth, the shortages, though noticeable nationwide, have been sporadic, and France gives no appearance of grinding to a halt. But in a country that by some measures consumes more butter per head than anyplace else, that is a fine point.