As promised, today we are going to talk about Vital Wheat Gluten, one of the more unusual ingredients in my Whole Wheat Banana Bread.
Remember the diagram from yesterday labeling the bran layers, germ and endosperm of the wheat berry? Well, Vital Wheat Gluten is made from the protein in the wheat berry’s endosperm. After the bran and germ have been removed from the wheat berry, the endosperm is then washed to separate the protein from the starch. This protein is then dried, ground into powder and sold as Vital Wheat Gluten Flour.
You might think that since we’re making healthy bread (and I know healthy is a relative term!), the purpose of adding Vital Wheat Gluten to bread dough is to boost the protein content. With Vital Wheat Gluten’s 75%-80% protein content, this is a good guess. Protein does a lot more, though, than simply providing us a daily quota of a particular macronutrient; it is pivotal in helping bread to rise.
If you were to hop on the Magic School Bus and take a trip inside bread dough as it is rising, this is what you would see: when the water and proteins (in form of flour and Vital Wheat Gluten) are mixed, you would see elastic sheets of gluten beginning to form. Then, these gluten sheets would begin to trap air bubbles. Meanwhile, the yeast would be feeding on the sugars in the dough and then release alcohol and carbon dioxide. When the alcohol and carbon dioxide collide with the trapped air bubbles, they would cause the air bubbles in the gluten sheets to enlarge and voila—the bread dough would rise. I think the chemistry of rising bread dough is a recipe for adventure for Miss Frizzle and her class.
Many of the flours used in the Healthy Bread in Five Minutes a Day are whole grain flours. Remember how whole grain flour contains the bran and germ in addition to the endosperm? In her science-laced cookbook Cookwise, Shirley O. Corriher explains, “Cup for cup, whole wheat [flour] will have less of the gluten-forming proteins than plain flour from the same wheat just because it contains these other parts of the kernel.”1 Less protein means less gluten, which means fewer opportunities for the formation of air bubbles necessary for the dough to rise. Yikes! We certainly want to make sure we have enough protein in our bread.
In order to capture the benefits of whole grain flour (fiber, vitamins, minerals and anti-oxidants) and still have a nicely risen loaf that is usually characteristic of a white flour loaf, we add more protein in the form of Vital Wheat Gluten. More protein = more gluten = a happier yeast bread.
In the end, it’s a win-win: by adding Vital Wheat Gluten to our whole grain bread, we get the nutritional benefits of whole grains and a finished loaf that has risen nicely.
**The 22 oz. Bob’s Red Mill Vital Wheat Gluten flour package from Whole Foods set me back $5.99. This may seem steep for 5 cups of what is essentially flour, but you’ll only use one tablespoon of Vital Wheat Gluten for each cup of flour in your bread, making it last through about 80 cups of flour.