Unbleached Flour vs Bleached Flour – What’s the Difference?

This week’s question comes to me from Catherine who writes:

“This is a question for Christine @ The Foodie File. I am not sure if you have covered this topic before but I was wondering what would be the difference in using unbleached flour as opposed to the usual all-purpose flour? Does it make a difference in the appearance of the baked goods? Thank you for your help. I really enjoy the blogs, very informative.”

This is a bit of a tricky question because, technically all flour that is used for baking is bleached. Milling a wheat kernel results in a pale yellowish-coloured flour that is left to age for a period of time. Aging the flour makes it better for baking because over time the proteins develop, which strengthen the gluten properties of the wheat. The added effect of this aging process is that the flour oxides and turns whiter or bleaches.

Chemical Bleaching
At one point all flour was treated this way. Then, somewhere around the 1800s, scientist came up with another method to age and bleach flour by adding chemicals to the milled flour. The result was a much reduced aging period, 48 hours as opposed to 12 weeks, and a much whiter end product. This process meant less time in a storage unit and therefore better profits and lower prices for flour. Consumers began to associate this ultra-white flour with better quality and soon the majority of flour produced was chemically bleached. The bleached flour that is chemically produced has a lower protein content then aged flour, therefore unbleached flour was still used in a lot of commercial baking, but even this has changed as consumers demanded whiter and whiter products.

Unbleached Flour
If the product is not labeled either way it has been chemically bleached. If you read the package you will find a bleaching compound present, either benzoyl peroxide or some type of chlorine. If a product is labeled unbleached, it has not been chemically bleached. Recently there has been a consumer demand for less processed food and therefore unbleached flour is making a comeback.

Does it Matter?
As to how each works is a matter of opinion. I took a quick survey in the Test Kitchen and the general consensus is that unbleached or bleached all-purpose flour act equally in a recipe. I have had the experience of having to adjust a pastry recipe when it had been developed with beached flour and I used unbleached instead – but it was a large scale recipe so possibly in smaller amounts it doesn’t make a difference. I do think that because of the stronger gluten properties, unbleached flour is better for making breads and yeast raised products than bleached flour. I also find that the texture is a bit different, unbleached flour tends to be a bit clumpier and so I sift if I’m making a cake or batter.

Is it Really Whiter?
If I’m making something that requires a fine texture I use pasty flour that for the most part is bleached – I have seen unbleached pastry flour but it’s not as available as bleached. As far as appearance goes, you may notice a slightly off white colour to a loaf of bread or cake baked with unbleached flour but it is pretty minimal.

More Flour Info:
Flour Facts
Gluten In Flour, Everything You Need to Know
What’s the difference Between Potato and Tapioca Starch or Flour?

Go Ahead and Stump Me!

Feel free to ask me any of your food-related questions, just leave a comment on any post in the Foodie-file. You will find a lot more answers to cooking questions under the Foodies Ask category of the Foodie-file.


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Posted in Foodie's Ask, The Foodie-file, Tue, 12/05/09

3 Responses

  • Valerie says:

    Some recipies call for cool whip…. I perfer to use real cream… my question is .. can you subsitute real whipping cream instead of cool whip.. usually used with Jello and cake recipies… and how long prior to eating can you make up these recipies… and once made how long (days) are they good for to eat

  • christine picheca says:


    I don’t see hwy you couldn’t use one for the other. I would experiment with using whipped cream instead a commercial topping (you would have to sweeten it though because whipped topping is already sweetened).

    I would imagine the shelf life would be about the same – whipped cream will last without spoiling for a few days but it will deflate in a short amount of time without any stabilizers, so really a day ahead is the most I would make a whipped cream dessert and a couple of days after to eat. If you are just using whipped cream straight up as a topping – whip it fresh because it will deflate.

  • Angela says:

    Hi Christine,

    When I got my bread maker years ago, I also remember reading about adjusting recipes from the U.S. when using Canadian flour. Of course, I can’t remember what the adjustments were that I was to make to recipes. Do you know? Also, when I lived in England, I was always playing around with recipes that included flour in order to get the texture correct. Do I have to make adjustments if I am using a British recipe?