Sift

To sift is to pass flour, cocoa or sugar through a fine sieve to break up lumps and add air. Here is when sifting matters and when you can skip it.

Also called Sifting, Sifted.

To sift means to shake dry ingredients through a fine mesh to remove lumps and loosen them. You sift flour, cocoa powder, powdered sugar (icing sugar in the UK), baking powder and spices. Sifting also mixes dry ingredients evenly. Use a sifter with a crank, or simply a fine-mesh sieve tapped with your hand.

How to do it

Hold the sieve over a bowl or a sheet of parchment paper.
Spoon in the dry ingredients.
Tap the side of the sieve with your palm, or stir the contents gently with a spoon, so the powder falls through.
Press any small lumps that are left through with the back of a spoon.
Throw away anything hard that will not pass through, such as bran or bits of paper.

Why it works

Flour and cocoa pack down and form clumps in the bag. Cocoa and powdered sugar also clump with moisture. Small clumps do not break up in a thick batter and leave dry pockets. Sifting also spreads leavening like baking powder and baking soda evenly through the flour, which stops bitter spots and holes in cakes.

Common mistakes

Measuring after sifting when the recipe means before, or the other way round. Sifted flour takes up more room, so a cup of sifted flour weighs less. A kitchen scale avoids the problem.
Skipping the sift for cocoa and powdered sugar. These lump the most and the lumps show in glazes and frostings.
Sifting whole wheat flour and throwing away the bran left in the sieve. Tip it back into the bowl.

In recipes

"1 cup flour, sifted" means measure the flour, then sift it. "1 cup sifted flour" means sift first, then measure. Modern all-purpose flour is fairly fine, so many recipes skip sifting and ask you to whisk the dry ingredients together instead. It still matters for light sponges, macarons and anything dusted on top. "Sift over" means dust a thin layer on top through a sieve, often as a finish.