How Different Flours Affect Your Cake

For the baker, there is a wide variety of flours to choose from when making a cake. Some of the options include: bleached cake flour, unbleached cake flour, pastry flour, self-rising flour, unbleached all-purpose flour and bleached all-purpose flour, not to mention starch substitutes and hybrid variations of some of those above. It can be a bit confusing which is the best flour for cake baking.  Here I hope to demystify some of the what’s and why’s of cake worthy flours.A-floursall-web

To illustrate the affects of varying flours, I baked six cakes each with a different flour type or combination. These included: unbleached all-purpose flour (UB) , bleached all-purpose flour (Bl.), bleached cake flour, potato starch plus unbleached all-purpose flour (a common cake flour substitute), half cake flour/half unbleached all-purpose flour and half cake flour/half bleached all-purpose flour.

Before we get onto the results of the baking, let’s talk about the differences in the flours.starch-and-protein-graphic2For this, I created a really awful graphic, but I thought a goofy little figure might help those of us that are über visual. This is an illustration of a baked cake using either cake flour or all-purpose flour.

There are two major differences between flours.

  1. Protein content: Cake flour is a low protein flour which means it contains more starch and less protein ounce for ounce than an all-purpose (plain) flour or a bread flour.  In the figure above you can see how this comes into play in a cake. The structure of the cake made with cake flour is mediated primarily by swollen starch granules with some structural help from egg proteins and the minimal protein found in cake flour.  All-purpose flour contains more protein and less starch by weight than cake flour and therefore the resulting cake structure is held together with more of a flour protein network.
  2. Chlorination:  Bleached flours have been treated with either chlorine dioxide or chlorine gas. This process not only lightens their color but also causes their starch granules to swell more easily and disperse fat more readily. Chlorination or bleaching also produces a distinct flavor that some people care for while others do not. The fact that chlorination leads to the accumulation of specific molecules in the body has caused it to be outlawed in the European Union and United Kingdom.  Cake flour is usually bleached but King Arthur offers an unbleached variation.


In actual cake, these are how the differences translate:

  • Unbleached all-purpose flour and bleached all-purpose flour appeared similar in color with a moist but slightly coarse crumb.
  • The bleached all-purpose flour rose just slightly higher than the unbleached.
  • Both the bleached and unbleached all-purpose flour cakes held together well.
  • The cake made with cake flour was taller and lighter in color than the all-purpose flours but was also drier and more crumbly/sandy .
  • The cake made with cake flour was more compact and less spongy seeming than the all-purpose flour cakes.
  • The cake flour cake had a slightly finer crumb than the all-purpose flours.
  • The cake made with cake flour tasted somewhat of chlorination.


  • The unbleached all-purpose flour with potato starch was the shortest and darkest of the cakes but it had a moist, tender crumb.
  • The half cake flour/half all-purpose flour combinations were almost identical to one another, but the bleached flour/cake flour combination rose slightly higher than the unbleached flour combination.
  • Both of the half cake flour combinations held together well and had a moist, tender, fine crumb.A-potato-color-web

So what is the best flour to use for your cake? That depends a lot on what you are looking for and what flour types are available to you. I prefer a combination of cake flour and unbleached all-purpose flour. I don’t care for the taste of cake flour so I try to limit the volume that I include. I also like the moisture and structure that all-purpose flour provides. This combination is essentially like pastry flour. If you have access to pastry flour I think it is a great option for cake.

On the other hand there are times when someone may want the whitest, tallest cake possible and therefore cake flour may be the best option.

The flour choice is really up to you and your preferences. I hope this information will help you to make an informed decision!

Happy baking!





41 thoughts on “How Different Flours Affect Your Cake”

  1. Hi Summer, thanks for those great insights. Having no access to cake or bleached flour, I usually combine UB with cornstarch. How similar is it to potato starch? Wpuld you recommend one over the other? Also we have wheat starch available here (though only in small packets). Would that be even better? Thanks for your reply! Love, Minh

    1. Cornstarch gives a similar result to potato starch. I think potato starch is slightly smoother and holds moisture a little better than cornstarch because it gels at a lower temperature and the starch granules retain more water. The differences are minimal though and I frequently use cornstarch in my cakes and cupcakes. Wheat starch might give you the most accurate substitute for cake flour, but if it is expensive and you can only access small amounts I wouldn’t bother with it. 🙂

  2. Once again you have posted an amazingly helpful, insightful, and well researched/documented post that I will refer to again and again. Thank you!!

  3. This was an awesome post, as always! But it has me thinking about the “Great Flour Debate” in the home cooked pizza realm… I think we’ll need to talk offline, since this site is all about cake!

    Thanks again!

  4. Hi, Summer. Thank you so much for sharing your knowledge with us all. You rock! I have a question about a recipe I am currently using that is giving me a bit of trouble due to being too moist and crumbling when cut. I use self-rising flour and a bit of corn starch (1 tbsp starch for every 1 cup of flour). The recipe also includes butter, oil, sour cream and buttermilk; VERY heavy on fats, i know, but it tastes amazing. It literally tastes like “more”, lol. I want to know if maybe using half AP flour or even adding a bit of AP or just more flour in general would help to stabilize the crumb for proper cutting. I usually add 1/4 tsp of baking soda, fyi. Here’s the recipe, in case anyone else may be interested. I got it from Couture Cakes by Rose on FB and tweaked it a bit.
    3C Self Rise flour, 2C sugar, 2sticks butter, 1C buttermilk, 2tsp vanilla, 4 eggs, 1/3c veg. oil, 1/4c sour cream, 3tbsp corn starch, 1 tsp baking powder, 1/4tsp baking soda

    Thanks again for all your helpful info 🙂

    1. Hi, Yes, I think that using half all-purpose flour would do a lot to improve the hold-togetherness of the crumb. I would also skip the cornstarch and just convert it into 1/4 cup all-purpose flour as well. Since you are using self-rising flour I don’t think the cornstarch is necessary. You might consider adding another egg too. That will add protein to help the cake texture without the drying effects of adding more flour. Be sure to compensate on leavening and salt if you cut half of the self-rising flour. Best of luck and let me know how it goes! 🙂

  5. Hi, I’ve just bought the KA unbleached flour blend for the first time. Do you have any experience using that, or tips on using in recipes asking for cake flour?

    1. Hi Samina, Did you get the unbleached cake flour or all-purpose flour? I have not tried their unbleached cake flour since no stores around here carry it and I have not ordered any yet. But I know others have had great success with it. I have used their other flours and they always produce nice products. It is difficult to say anything specific about cake flour containing recipes because it will depend on how the recipe is formulated, but if you are going from a recipe with cake flour to one with all-purpose you can usually sub ounce for ounce. If you are going the other way you may need to add a touch more liquid, but like I said it would have to be determined on a cake to cake basis. Sorry I can’t be more definitive. Recipes can vary so much! Best of luck. Let me know if you like the KA flour. 🙂

  6. If I had a recipe that calls for 2 cups of cake flour but want to substitute some of it with all purpose what ratios would I use? I don’t like the taste of cake flour used by itself.

    1. Hi Genia, I like a 2/3 all-purpose to 1/3 cake flour for most cakes, but you can do half and half also. Cakes with more cake flour get stale and crumble more quickly so I try to keep it on the lower end. If a cake is a bit coarse with 2/3 all-purpose sometimes I will shift toward more cake flour. I hope that helps!

  7. Thank you Summer for this great article. I always wanted to know more about the different flour types you have in America. In Europe there are way less types of flour available, at least for the average consumer.
    I think I read somewhere that you can substitude American cake flour with a mixture of all-purpose flour and starch. Do you know a ratio for that – I think its like one cup of flour – 1 tbls + 1 tbls of starch?
    Also, is your UB+Potato Starch mix a half and half ratio? I think I over read that.

    Thank you so much for sharing your incredible wisdom 🙂 – I really love your blog!


    1. I use 7/8 cup all-purpose flour to 1/8 cup starch. I actually think that the all-purpose flour alone was an overall better cake though. Good luck and thank you!

  8. Hi Summer, As always you ROCK!!! I’m wondering who gets all your left overs (volunteering), because it seems you would have a lot. I use your vanilla cupcake recipe for all my vanilla/almond cakes and everyone loves the texture and flavor. I did change it a bit by adding 1 cup AP flour and the rest as cake flour. Now I’m wondering, based on your other comments, if I should use 1 cup cake flour and the rest as AP flour. Sorry I don’t have the recipe with me right now but I believe the total flour amount it 2 3/4 cup. I feel the cake is better when the flours are mixed and it would appear your experiment confirms that. I also find it a struggle not to over mix this recipe but I think I have it down to a science now and the outcome is beautiful. Someone indicated tunnels are a sign of over mixing and I was seeing them initially but after cutting back on the mixing I see fewer. Perhaps you have another thought on why I was getting tunneling. Thanks again, Joyce

  9. Hi Summer. I came over to your blog after reading your SMBC method on pinterest. I am going to have to try that. Would you be willing to provide the recipe for the cake in this blog? would love to do my own experiment and don’t have a good white cake recipe. Thanks!

    1. Here is the recipe for the vanilla flavored cake in the Flour Variation post. For the instructions follow the link to the Vanilla Cake as they are the same. The flour used in this recipe is half cake and half all-purpose but you can try whatever proportion you like. You may also like the White Cake. Let me know if you have any more questions! 🙂
      Vanilla Flour Variation Cake
      • 16 tablespoons (8 ounces, or 227 grams) unsalted butter softened
      • 11 ounces (315 grams) granulated sugar
      • 4 large eggs
      • 1 tablespoon (15 milliliters) vanilla extract
      • 6 ounces (170 grams) all-purpose flour- 1 ¼ cups
      • 6 ounces (170 grams) cake flour*- 1 ½ cups
      • 1 ½ teaspoons baking powder
      • ½ teaspoon baking soda
      • ¾ teaspoon salt
      • 1 ¼ cups (300 milliliters) buttermilk

  10. I noticed in your Italian cream cake you said you don’t like to use shortening but what if I want a true white cake, and I use srf (self rising flour) could I use that in your cake recipes. I have looked through and your white cake looks more moist and fluffy than the vanilla cake could that be from, the milk. In your recipes could I use srf with cake flour, and in the white cake and velvet white could I use, srf with cake flour and shortening. I have been looking to use sour cream and buttermilk in my cakes together but was not quite sure, here is my recipes here, and I use (2cups srf )omitting the baking soda n salt.
    1 1⁄4 cups sugar
    1⁄2 cup Crisco shortening (white only)
    2 large eggs (or extra large) or (3 whites)
    2 cups all-purpose flour
    1 teaspoon baking soda
    1⁄4 teaspoon salt
    1 cup buttermilk
    2 teaspoons vanilla
    Thanks for your help.

    1. You could use shortening but it does not give the best cake results (see Fat Post). If I wanted a true white I would use butter and add white food coloring to compensate. Yes, you can use srf! Just be sure to compensate and remove a proportional amount of leavening. There are a lot of factors that go into texture in a cake, so it is not easy to say why the vanilla cake is different than the white cake. Just overall formulation. I hope that helps! 🙂

      1. ahh yes I hav seen your fat post, didn’t kno that was you, that was when I first came across you and didn’t know it

  11. ahh yes I hav seen your fat post, didn’t kno that was you, 🙂 that was when I first came across you and didn’t know it, I hav tried the white good coloring didn’t quite work, used a whole little tube, unless I used the wrong kind, is there one you perfer? I will go back to butter with my cakes, I will try to perfect the white cake cake with shortening just like a pure white cake and for my cocount cakes, just perference, I will definitely get some cake flour and mix that with my srf and see how that does, hopefully, fluffy moist cakes. Thanks for alol your help greatly appreciate it.

  12. Great article! Thanks for testing all of the variations!

    I don’t understand one part of your summary. You say:
    “The cake made with cake flour was taller and lighter in color than the all-purpose flours ….
    The cake made with cake flour was more compact and less spongy seeming than the all-purpose flour cakes.”

    How can the same cake be taller, but also more compact than another variety? To me, compact means shorter. By ‘compact’, do you mean that the crumb is tighter? (less open?)

    We usually measure cakes in terms of tenderness. Was the cake made with cake flour more tender than that made with all-purpose? I assume that “spongy” means tough?

    Thank you!

  13. Hi there
    My daughter has some very strict dietary restrictions and I would love to be able to make a cake for her that tastes and holds well. She is on a strict low protein diet which means for making a cake she cannot use normal flour or eggs. We can use most starches and egg replacer but it’s always crumbly or gummy. I have no idea if it’s possible to make something using a mixture of starches but would love some advice.
    Thank you in advance 🙂

    1. Hi Sasha, Baking with dietary restrictions can be very tricky. Often cakes made with starches rely on alternate protein sources to hold things together so I can understand how it would be difficult to meet all of your requirements. You need the right combination of starch and binder. For a binder you will likely need to use a gum or combination of gums (xanthan, guar, etc.). Since you won’t have protein for structural support it is probably best to keep your layers very short and bake more layers. The key to finding a recipe that works will be ingredient balance and unfortunately that takes experimentation. If I have a chance to play recipes I will let you know. Everyone should be able to enjoy yummy cake!

  14. Hi Summer: Thanks so much for this side-by-side comparison of cake flours. I was debating going unbleached cake flour for recipes calling for cake flour, but I like your idea of using a mix of AP & cake flour.

    And thank you for confirming that using cake flour by itself tends to lead to a drier cake. I thought all the cakes in Rose Beranbaum’s “Heavenly Cakes” were just awful despite all the pretty photos. Now I know it’s the flour, I’m going to go back and try some recipes with a mix of AP and cake flour.

    1. Here is a comparison with even more flours if you are interested:
      Which Flour is Best?
      I have become a big fan of Bob’s Red Mill unbleached cake flour if you can access it. If not, the half cake half all-purpose flour is a great option!

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