The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Purposely Oxidized my Bread

DoubleMerlin's picture

Purposely Oxidized my Bread

Hello all,
I grind my own whole wheat, and have had problems with directly making breads with fresh-ground WW flour. That is, too slack, a poor rise, and absolutely NO oven spring. I had checked out Functional Additives in Baked Goods (Stauffer 1990) from my school's library for a little reading material and read about oxidation agents. Most flour is purposely oxidized to a certain degree to get a tighter gluten, better rise and oven spring. Big companies use bleaching agents to accomplish oxidation in less than an hour. Compare that to letting fresh flour sit for 4 to 14 days to get the same degree of oxidation, and it makes sense. Because I grind my flour about 5 lbs at a time, most of my flour is oxidized by the time I use it, although the first bread I make with the flour is often problematic.

Besides chemical bleaching agents (Chlorine dioxide, azodicarbonamide, bromate), there are alternatives. Europeans use fava bean flour at 1-2% to get the same degree of oxidation. Some folks say this is why european bread isn't good any more, but I'm young and the european breads I've had are still better than quick-oxidized breads in the US.

So, to try to ameliorate my fresh flour problems, I added 1-2% ground garbanzos. According to this, whole garbanzos do have a sizable amount of lipoxygenase activity, the enzyme that promotes oxidation.

My formula was as follows:
200 g whole wheat flour (not freshly ground, ~3 weeks old, with 5% malted wheat)
100 g water
100 g overproofed starter
400 g Starter (after 12 hrs)
170 g old whole wheat flour (with 5% malt)
330 g freshly ground whole wheat
350 g water
18 g "real salt"
8 g fresh ground garbanzos
30 g vegetable oil (soybean)

Procedure: Mixed to uniformity, not kneaded. Set at ~30-40˚F for 16 hrs. Removed from refrigeration and kneaded. Now here were the differences obvious. This same dough with naturally oxidized flour is pretty tight, but kneadable. With fresh flour it rips too easily, and takes forever to get the proper amount of development. With the garbanzos, this dough was one of the most difficult breads I've ever kneaded. I considered adding more water, but decided against it. I shaped it as best I could and left it to ferment. It was 2 hours at 65-75˚F before I went to bed, putting it again at 30-40˚F. This morning I took it out again and it has been fermenting 2 hours now, and is almost double right now. I will bake it at 450˚F in a preheated cast iron lined with grits and parchment. Pics to follow.

David Esq.'s picture
David Esq.

Are your later loaves with the older flour rising properly? Most of what I read suggested people home milling had fine results baking the same day as the grind.

The green flour phenomenon seems to be more of a problem with white flour that has had all of the nutrients removed. But you have the problem with fresh whole wheat flour and not the older stuff?

DoubleMerlin's picture

yes, my green flour, as you call it, has only resulted in real stumpy loaves. After two weeks or so it works fine. I'll post some pictures of this loaf tomorrow when I cut it.

I would think you're right that green flour would be a problem for white breads mainly. I'm not sure. Wheat flour is way more complex of a system than one would think...

dabrownman's picture

with green flour and love its taste but i don't grind  5 pounds of it at a time to see how it might change over time.  I just grind exactly what I need so it is as fresh as possible and haven't noticed anything unusual.  But, I donl't usually make a 100% whole wheat SD bread either.  We make a 3-8 multigrain grain one with green flour that I could test it on though.  It wasn't a flat loaf this past Friday for the 100% whole grain loaf  but, I didn't get the spring and bloom that I expected.   I just chalked it up to a few hours less proof in the fridge than usual and baking it cold straight out of the fridge with no warm up. 

We love experiments around here and this sounds like a good one to test out.  I see you malt your whole grains.  I only have garbanzo bean flour in the freezer  but suppose that would still work?  I had heard that if you don't use green flour right away, you have to let it age at least a month?    I always thought that is was a myth put out there by flour millers to try to stop folks from milling there own flour :-)

We will find out soon enough. 

Happy  Baking

DoubleMerlin's picture

So this one turned out as I expected. Way too tight of a crumb. The rise petered out after 4 hours, never getting much larger than 50% expansion. It tastes great, but it's dense. As BBA says, this one ought to taste better after sitting a while.


nicodvb's picture

why don't you add pure vitamin C? It works VERY well, even if overdosed, dissolved in the water.

Technicians  generally recommend to use 100mg for 1kg flour, but I verified that with weaker flour (such as wholemeal) a larger dose (300-500 mg per 1kg flour) makes miracles! Legume flours have many ingredients that influence dough rheology, not only LAX.

Vitamin C is a reducing agent, but it reacts with an enzyme present in the flour to become dehydroascorbic acid, that is an oxidizer.

Bob S.'s picture
Bob S.

I had not heard of using fava bean flour as a bleaching agent before, but it comes as no surprise. American bakers have long used enzymatically active soybean flour for bleaching and dough improvement. The enzyme of primary interest is lipoxidase, which brings about the oxidation of linoleic and certain other polyunsaturated fatty acids. Bleaching is accomplished in a coupled reaction, which renders carotene colorless.
Linoleic acid is present in many vegetable oils, including soybean oil (48% - 57% linoleic acid). By having enzymatically active fava bean flour and soybean oil in a bread formula, the uptake of oxygen is increased. Besides bleaching, the oxidation of linoleic acid reduces mixing time and increases mixing tolerance, although exact mechanism remains unknown.
Before switching from liquid oils to solid shortening for bread-making, my oil of choice was grapeseed oil. The bread that I baked with grapeseed oil exhibited better oven spring than olive oil (6-14% linoleic acid), leading me to believe (incorrectly) that the oil contained some kind of oxidizing agent. I even went so far as to add grapeseed extract to my dough, hoping to achieve dough improvement (to no avail).
As it turns out, grapeseed oil contains a large percentage of linoleic acid (60-75%). I now think that the improving action of grapeseed oil came from the oxidation of linoleic acid by lipoxidase, which is naturally present in wheat flour. I may give grapeseed oil another try, this time supplemented with raw fava bean flour.