sift
Also known as: sifted, sifting
Passing dry ingredients -- most often flour, alone or already combined with baking soda, baking powder, cocoa powder, or salt -- through a fine-mesh sieve or sifter to break up clumps and spread anything mixed in evenly throughout before it goes into a batter or dough.
How to do it
Set a fine-mesh sieve or sifter over a mixing bowl, add the dry ingredients, and either tap the side of the sieve or work the sifter's handle or trigger until everything has passed through. Done correctly, what lands in the bowl looks light, loose, and even -- no visible lumps, and no denser pile where a clump of flour or a pocket of baking soda sat. If more than one dry ingredient is being sifted together (flour with a leavener and salt, for instance), one pass mixes them at the same time it aerates them, so there's no need to also stir them separately afterward.
Common pitfalls
- Measuring flour by volume without matching what a recipe's instructions assumed -- sifted-then-measured flour packs noticeably looser than scooped-then-leveled flour, so treating the two interchangeably can throw off a cup measurement by several tablespoons' worth of flour.
- Skipping a sift when a recipe calls for it and a leavener is involved -- an unbroken clump of baking soda or baking powder that never fully disperses into the batter can leave a small bitter or metallic-tasting spot, or an uneven rise, right where it landed.
- Sifting well ahead of time and letting the bowl sit uncovered -- flour reabsorbs humidity from the air fairly quickly, which settles it back down and undoes much of the aeration sifting just added.
Why it works
Flour settles and compacts in its bag or container over time, and fine powders like baking soda, baking powder, and cocoa can clump wherever they've picked up a little moisture. Sifting breaks up both kinds of clump and, in doing so, works air into the pile -- which is also why sifted flour takes up noticeably more volume than the same weight of flour scooped straight from the bag: a cup measured after sifting holds less flour by weight than a cup measured before it. A recipe that specifies sifted flour is relying on that lighter, more consistent volume, not just a smoother-looking pile.
Equipment
A fine-mesh sieve held over a bowl and tapped or stirred with a spoon works for almost any job; a dedicated sifter (a canister with a hand-cranked or trigger-driven mesh) is faster for a large quantity of a single dry ingredient but less versatile, since a sieve also strains liquids and purees where a sifter can't.