The Science of Flour

the science of flourWhen growing up in Iceland bread was normally a big part of breakfast, lunch and an after school snack. It was our go-to food to fill you up. As an adult today I still love bread and it is a big part of my family’s diet. So when I started on the path to remove processed food out of our pantry, white bread and bleached flour became the first things to be removed.  Here is why.


Bleached Flour

Bleached flour today does not contain bleach despite its title but has other types of chemicals that are not very desirable for our bodies. To understand white flour better let’s look at the process of making it. White flour isn’t really white, after it has been milled it is yellow, the depth of the color depends on how much germ and bran is left in the flour after the milling and sifting. Us humans are very visual when it comes to our food and yellow flour was not desirable 100 years ago, and still isn’t today. The bleaching process allowed the miller to use cheaper and less quality grade of wheat and sell it to the buyer as nice white bleached flour which was much more appealing to the consumer then yellow.

Aging Process

All flour has to age for a certain amount of time and the longer the better. If not allowed to age properly your bread will crumble and fall apart. Gluten is what gives the bread elasticity and structure and the more the better (for those who don’t have gluten allergy). When the flour is allowed to sit in the open for certain amount of time the flour will oxidize, the glutenin will become gluten and a quality baking flour is created. Typical timeframe is 10 days, but many bakers prefer it to sit for 4-5 months. Unfortunately most bakers and millers don’t have the storage space to let the flour sit that long nor is it profitable for them. So in order to keep up with supply and demand, chemicals are used to speed up the aging process which in return creates more profit.

The Chemicals

I never thought to read the ingredient list on a pack of flour before I started researching why white bleached flour is bad for you. I have listed the most common chemicals you might see on the label for bleached flour.

Potassium Bromate (E924) strengthens the gluten development and the aging process. This is a very powerful oxidizing agent, if too much is added or if the bread is not baked at a high enough temperature then a residual amount remains which is harmful if consumed. Bromate is a category 2B or a possible carcinogenic to humans, it has been banned in EU, Canada, Nigeria, Brazil, China and some other countries.

Benzoyl Peroxide is a bleaching agent for the flour. It is also used as an acne treatment, bleaching hair and teeth and can be found in some of the products in your cleaning cabinet. Studies have highlighted Benzoyl Peroxide as a possible carcinogenic agent.

Azodicorbonamid (E927) is an aging and bleaching agent in flour it is also commonly used in plastics and synthetic leather. It is banned in Europe and Australia as an additive in food.

Chlorine Gas is both a bleaching and a maturing agent but it weakens the gluten development. It is mainly used in cake flour as it oxidizes the starches in the flour making it swell more when in contact with water. This is bad for bread making which is heavily dependent on gluten. Chlorine gas is also banned in EU countries.

Nitrogen Dioxide was one of the first agents used to bleach flour, but also acts as an aging agent. It has also been used as a rocket fuel and strengthening agent in paper alongside being used to bleach flour.

Ascorbic Acid (E300) is primarily used as an aging component but can also be used as a dough enhancer. This is an unnecessary additive as it can weaken the gluten in longer-fermented dough.  Ascorbic Acid is also known as vitamin C but consuming ascorbic acid that is used in baking does not have the same benefit as vitamin C you get from fruits it is largely degraded and its residues no longer have the of the beneficial properties of vitamin C.

A scary list, if you weren’t before convinced to read the label on your flour, hopefully now you are.  You don’t have to have a chemical degree to realize this just can’t be good for you. My suggestion is to substitute bleached flour with unbleached and for you pastry makers King Arthur brand is the only one I know off that offers unbleached flour suitable for cake making.


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