There are lots of recipes out there that call for sifted flour – particularly cake flour – and even more that ask you to sift together dry ingredients before incorporating them into the batter of whatever it is you’re making. Do you need to have a flour sifter to ensure that the recipes work properly? And for that matter, does flour really need to be sifted?
To start with the second question, the answer is that flour and other dry ingredients, including cocoa powder and confectioners’ sugar, sometimes do need to be sifted. The finer your ingredient is, the more likely it is to clump up in its storage container. If you live somewhere very humid and don’t use airtight containers for flour,etc., clumping may also be more likely. Sifting can break up clumps of flour/sugar/cocoa that might not otherwise break down with simple stirring and prevents these clumps from holding their shape in your finished product. When it comes to sifting multiple ingredients together, sifting can help give you a more even distribution in the mixture. This just speeds up the work that otherwise needs to be done during mixing to ensure that your salt or leavening is well-incorporated into your batter.
But flour doesn’t always need to be “sifted” with a flour sifter. You can certainly use one if you like the look or feel. I personally find flour sifters to be a bit of a pain, especially since I like to sift cocoa and other ingredients and they can be annoying to clean. I tend to use a large sieve for sifting fine ingredients, particularly cake flour and cocoa powder. It works incredibly fast, is easy to clean and can also be used in other kitchen applications. If I just want to evenly distribute flour, leavening and salt (say, in a batch of cookie dough), I’ll skip the sifting and just use a whisk to fluff the mixture up. I tend to call for this when I write recipes, only specifying that an ingredient needs sifting when it is required.
So, have a large sieve or two around to help out in the kitchen, along with a whisk. For the vast majority of home baking, they’re all you’re ever going to need as far as flour sifting goes.