If you look at nearly any baking recipe, you will see something like “sift together the dry ingredients,” usually flour, baking powder and maybe sure and salt. Why do they do that? Well, because someone clear back to Fanny Merritt Farmer, in her Boston Cooking School Cookbook (you can read a digital copy here) said to. Flour in 1896 was probably much lumpier than today, and she said to sift all ingredients before measuring them.

Nowadays, flour isn’t usually very lumpy and we usually use it right out of the bag.

But we thought we’d try sifting some paprika into flour to see how well it mixes. This is about 1.5 Tb of paprika in 2 cups of flour.

 

As can see, it doesn’t really mix all that well. In fact, you could do better just using a wire whisk. But, if you are making a batter for baking, the mixing of the dry ingredients with the liquid will distribute them just as well.

Now about that cup

A measuring cup measures 8 fluid ounces: it is really for measuring liquids like milk or water. Flour, not being a liquid can be a little variable about how much fits in a cup. Fanny Farmer said you should scoop out the flour and level off the cup with a knife, and that works for 1 cup of flour. But for 2 ½ cups of flour, it gets messier and it soon becomes easier to weigh out the flour. We have an inexpensive kitchen scale, Ozeri kitchen scale (it cost $15.95), we keep right with our bowls and dishes, and can easily weigh anything we want.  If you don’t have one, ask someone to give it to you for Christmas.

So how do you weigh out flour? We found that 1 cup of King Arthur All Purpose Flour weighs 142 g (see above). We use grams because then there aren’t any pesky decimal pl aces to confuse you.

---

---

But what about sifted flour? The only thing sifting commercial flours does is to aerate them a bit so a cup of sifted flour weighs less. Sifted King Arthur flour weighs 126 grams, or about 8% less.

Cake Flour

Cake flour is made from a mixture of lower protein wheats that will give a light and tender crumb in cakes. According to Harold McGee in On Food and Cooking, all purpose flour has about 11-12% protein (mostly gluten) and cake flour about 7-8% protein. And U.S. cake flour is bleached as well, which causes “the starch granules to absorb water and swell more readily in high sugar batters.” Need less to say, cake flours weigh less per cup:

	All purpose	Cake flour
Scooped	142 g	120 g
Sifted	126 g	112 g

These weights are useful when you need some off amount of flour. For example, my waffle recipe requires 2 ¼ cups of sifted cake flour. It’s easiest to just quickly weigh about (2.25 x 112g) or 252g in a dish and mix it into the waffle batter. I keep this table posted inside my cupboard door, and write the weights into any recipes I use frequently.

So, get your scale out and you can do your baking quickly without getting a lot of measuring cups dirty. Happy holiday baking!

• Chemistry
• Food science
• Science