What's the Purpose of Sifting Flour and Other Dry Ingredients When Baking?

When a recipe calls for sifting flour, confectioners' sugar, or cocoa powder, it may seem like an extraneous step, but it is actually the key to super light and fluffy baked goods. Whether you use a traditional flour sifter with a hand crank or a fine-mesh sieve, this baking technique serves a dual purpose. "One, you get a lot of air in the flour, so you get a light crumb," says Odette Williams, baker and author of Simple Cake: All You Need to Keep Your Friends and Family in Cake ($13.99, amazon.com). But it also helps to distribute dry goods such as flour, cocoa powder, baking powder, and salt more evenly, Williams adds. "By doing this simple step, you'll get a sublime cake, rather than 'it'll do' cake." Ahead, we're explaining when to sift flour and are sharing two of our favorite products to help you get the job done.

Related: Why Every Baking Enthusiast Needs a Kitchen Scale

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When to Sift Flour

Even if a recipe doesn't state that sifting dry goods is needed, Williams says she always does it. "I don't think it hurts—it lightens the load," she says, meaning that the result will be a more cloud-like and moist product, rather than something super dense. Certain types of flour, such as pastry or cake flour, are naturally lighter because they have a lower protein count than all-purpose flour. However, she still says sifting them is fair game.

It's important to read your recipe carefully before sifting anything, though. Some recipes will measure ingredients by weight, rather than by volume, and sifted flour will clock in at a different weight than un-sifted flour. "Some cookbooks will say what the weight is before or after it's been sifted. If it doesn't state the weight, then you should assume that is for un-sifted flour," says Williams.

When Not to Sift Flour

Williams says there are very few times when it wouldn't be beneficial to sift dry goods. However, there is one recipe where you can skip this step. "You will never see sifting flour for tempura batter in a recipe," she says. Tempura batter is a light and airy batter made with just flour and seltzer water. It is used for coating meat, seafood, and vegetables for deep-frying; the result is a super, light, super crispy coating. In this case, Williams says you actually want a few lumps in the batter, which will help give it airiness.

Another instance when it may not be necessary to sift flour is if you're mixing buttercream in a stand mixer. Sifting confectioners' sugar doesn't make a difference in the final result of the frosting—it's just about getting out any lumps. "If you're going to make frosting in an electric stand mixer, then sifting isn't all that important because the beater will break up the lumps," says Williams.

Types of Flour Sifters

The two most common products for getting the lumps out of dry ingredients are a flour sifter or a fine-mesh sieve. Williams says you can always use a large whisk if you don't have a flour sifter or sieve because it will still work hard to break up any lumps in the batter.

Courtesy of Macy's

Martha Stewart Collection Three-Piece Sieve Set

Our founder's set includes three different sizes—use the smallest for dusting confectioners' sugar over cake or cookies and use the medium and large sizes for sifting dry ingredients into a mixing bowl. Williams prefers using a sieve because it can take more volume than a flour sifter.

Shop Now: Martha Stewart Collection Three-Piece Sieve Set, $32.99, macys.com.

Courtesy of Macy's

Martha Stewart Collection Deluxe Flour Sifter

This handheld flour sifter uses a hand clamp to move dry goods through the thin, fine mesh, allowing you to create a light, lump-free batter or frosting. It has a capacity of just two-and-a-half cups, so it's best for smaller batches of ingredients.

Shop Now: Martha Stewart Collection Deluxe Flour Sifter, $20.99, macys.com.