Croissant Day

What the day is

Croissant Day is observed on January 30. The pastry is laminated dough: a yeasted dough with a block of butter folded into it repeatedly, so that baking turns the trapped water in the butter to steam and forces the layers apart.

That structure is the whole test. A good croissant shatters slightly when squeezed, shows an open honeycomb inside rather than a bready crumb, and leaves flakes on the plate.

Origin and background

The origin of the observance is not documented. The pastry's ancestry is Austrian: the kipferl, a crescent-shaped baked good, predates the croissant by a long way. A popular story ties the shape to the 1683 siege of Vienna and the Ottoman crescent, with bakers commemorating the city's survival. It is a good story and historians generally regard it as invented after the fact.

The documented route into France runs through a Viennese bakery opened in Paris in the 1830s, which introduced kipferl to Parisians. The laminated, yeast-raised version recognizable today developed later, in the early twentieth century, and it is that technique rather than the shape that makes a croissant what it is.

One French convention is worth knowing at the counter: an all-butter croissant is traditionally shaped straight, while the curved crescent indicates margarine or another fat. The distinction is not universal, but in France it is a reliable signal.

How to take part

• Buy from a bakery that makes its own. Weight is the giveaway: a proper croissant feels light for its size.
• Eat it the day it is baked, ideally within hours. Lamination goes stale fast, which is why yesterday's croissant is a different food.
• Refresh a day-old one in a hot oven for a few minutes rather than a microwave, which turns it to leather.
• Try making them once. It takes two days, mostly waiting, and it permanently changes how you judge a bakery.
• Keep butter and dough at the same cool temperature if you do. Butter too cold shatters into shards; too warm and it merges into the dough and the layers vanish.