Levure chimique vs. poudre à pâte
These two terms describe the exact same culinary ingredient used to make batters rise, but they belong to different geographical varieties of the French language. While levure chimique is the standard term used in France and most of Europe, poudre à pâte is the term used in Quebec and French-speaking Canada.
Levure chimique
B1This is the term used in France and standard European French. It literally translates to chemical yeast to distinguish it from biological baker's yeast (levure de boulanger) used for bread. It is typically sold in small pink or single-use sachets in Europe.
J'ai ajouté un sachet de levure chimique pour que le gâteau soit bien moelleux.
(I added a packet of baking powder so the cake would be very moist.)
Il faut tamiser la farine avec la levure chimique avant de mélanger.
(You must sift the flour with the baking powder before mixing.)
Si tu n'as pas de levure chimique, tes muffins ne monteront pas.
(If you do not have baking powder, your muffins will not rise.)
La recette demande 11 grammes de levure chimique.
(The recipe calls for 11 grams of baking powder.)
Ne confonds pas la levure chimique avec le bicarbonate de soude.
(Do not confuse baking powder with baking soda.)
Poudre à pâte
B2This term is used exclusively in Canadian French (Quebec). It is a direct translation (calque) of the English term baking powder. In Canada, this product is usually sold in a tub or a can rather than small sachets.
Grand-maman met toujours de la poudre à pâte Magic dans ses recettes.
(Grandma always puts Magic baking powder in her recipes.)
Est-ce qu'il reste de la poudre à pâte dans l'armoire ?
(Is there any baking powder left in the cupboard?)
Au Québec, tout le monde dit poudre à pâte au lieu de levure chimique.
(In Quebec, everyone says baking powder instead of chemical yeast.)
Mélange les ingrédients secs incluant le sel et la poudre à pâte.
(Mix the dry ingredients including salt and baking powder.)
Cette poudre à pâte est expirée, elle ne fonctionnera plus.
(This baking powder is expired, it will not work anymore.)
Summary
The chemical leavening agent is the same in both cases, but the vocabulary changes based on location. Use levure chimique when speaking to a person from France to ensure they do not confuse it with yeast for bread. Use poudre à pâte when speaking to a Canadian Francophone, as it reflects the North American terminology.