What happens when wheat flour is sieved before making dough?

1. Aerates the flour: This removes air pockets and clumps, resulting in a lighter and fluffier dough. This is especially important for recipes like cakes and pastries where a delicate texture is desired.

2. Removes lumps and impurities: Sieving helps eliminate any lumps or foreign particles like small stones or bits of bran that might have gotten mixed in during the milling process.

3. Distributes leavening agents evenly: When baking with baking powder or yeast, sieving ensures their uniform distribution throughout the flour. This leads to more consistent rising and a better-textured final product.

4. Makes the flour finer: Sieving can break down larger flour particles, resulting in a smoother and more uniform texture in the final dough.

5. Incorporates dry ingredients more easily: When making dough, sieving helps combine flour with other dry ingredients like sugar and salt more effectively.

However, sieving is not always necessary. For example, in bread-making, where a strong gluten structure is desired, sieving can actually be detrimental.

Here's a quick summary:

* Sieve when: You're making cakes, pastries, cookies, or other delicate baked goods.

* Don't sieve when: You're making bread or other doughs where a strong gluten structure is crucial.

Ultimately, the decision to sieve or not comes down to the specific recipe and desired texture.