The Science Behind How to Make Whole Wheat Bread
Just Why Does Your Homemade Bread Recipe Rise and Bake?
Home cooks learning how to make whole wheat bread often ask, “Why didn’t my bread rise? What went wrong?” It could be the temperature, the leavening, gluten content, or humidity. Understanding the science of why bread rises helps eliminate problems.
Bread: A Broad Definition
An ancient food, bread is essentially a mixture of milled grains and water. It could be crafted out of rice, wheat, corn, amaranth…the possibilities are broad. And each grain adds a different quality to the finished product.
An important food item since the dawn of agriculture, recipes aligned with the areas in which they developed. Yeast lives naturally on the surface of cereal grains, so any ground flour, mixed with water and left in a warm enough environment, will ferment and rise to give the bread a lighter texture. Unleavened matzoh symbolizes a Biblical time when the children of Israel fled and didn’t have time for bread to rise. Gauls and Iberians, during the era of Pliny the Elder, skimmed foam from beer to add even more yeast, producing a lighter bread than was available in surrounding civilizations. And in Ethiopia, a unique gluten-free grain called teff is ground down and allowed to ferment for several days before it’s cooked into a flat, spongy product called injera.
A basic bread recipe involves ground flour moistened with water. Adding sugar, leavening, fats, and salt controls the rising process, influences texture and flavor, and affects storage life.
The most common grains used for bread are wheat species and rye. When learning how to make whole wheat bread, bakers can simply grind wheat berries into a fine powder. This method creates an extremely nutritious product since the wheat’s hull and germ also go into the flour. But bread made with 100% wholegrain wheat flour can be heavy. This used to be a baker’s objective; they could be fined for selling a “light loaf.” But among the wealthier, for whom maximum nutrition for each penny spent wasn’t so critical, fluffier loaves gained popularity. When grinding rollers were invented around 1870, it was possible to separate the hull and germ to produce fluffy, white flour. White bread was suddenly in vogue. It rose quicker, was softer and had a lighter flavor. But the new technology removed the most nutritious part of the grain, resulting in widespread nutritional deficiency diseases. Now flours are “enriched,” refortified with vitamins so we can enjoy fluffy baked items and retain more nutrition.
Mixing whole grains with white flour also combines both qualities: nutritious, fiber-rich bread that still rises soft and fluffy. Many recipes for how to make whole wheat bread only use wholegrain flour for half of the content. The other half is all-purpose or higher-protein bread flour. For the best whole grain bread recipe, search for one which utilizes several different flours.
In parts of the world where wheat isn’t as widespread, or where people cannot consume gluten, other grains are mixed for the best texture. Rice flour is inexpensive but can be heavy and grainy. Tapioca starch adds fluffiness but little flavor. Though it’s not a grain, almond meal increases protein. Highly nutritious amaranth is also highly expensive and best used for a small percentage of the mixture. Because these grains do not contain gluten, the protein responsible for traditional bread’s springy texture, gluten-free breads are often dense unless an aggressive combination of yeast and emulsifiers is added.
To rise into something other than a hard wafer, bread needs leavening. This creates carbon dioxide, which pushes through the product to make air pockets.
Batter breads use chemical leavening such as baking powder or self-rising flour, which foam up when they meet water. Others involve alkaline baking soda to combine with acids such as oils, pureed fruit, buttermilk, or beer. Chemical reactions make air bubbles throughout the loaf. This method is used for banana bread, muffins and cakes, soda bread, buttermilk biscuits, and non-sourdough pancakes.
Sourdough starters contain the microbes yeast and lactobacilli. The sour flavor comes from the lactobacilli, which is kept alive by “feeding” the culture within the starter. This is the original yeast-leavening method since the actual microbes weren’t discovered and isolated until the 19th century. Household members baked on a fixed schedule to ensure the culture stayed healthy. Bakers saved liquid starter from the previous batch, leaving it to grow for a few days, then scooped out a little to save for next week. The baker then added more ingredients and crafted the bulk of the starter into loaves, marked each loaf with a sign according to family or customer, and sent them to a communal oven. Starters traveled overseas, across prairies in covered wagons, and were given as gifts to new brides. When baker’s yeast become available, sourdough lost popularity until a recent revival in artisan techniques.
When yeast was discovered, strains of Saccaromyces cerevisiae, the same species used to brew beer, were bred and distributed. This allowed loaves to rise and bake within a few hours instead of a few days. Dry packages purchased in stores are baker’s yeast. When this microscopic fungus awakens with warm water, it consumes carbohydrates within the recipe to create carbon dioxide. Some bakers pre-ferment yeast, flour, and water a day ahead of time while others make a “straight dough,” combining all ingredients then mixing it and leaving it to rise. Additives such as salt, sugar, eggs, and oil slow down yeast growth. A well-balanced recipe combines these ingredients to produce a perfectly risen loaf if instructions are followed correctly. While a potato bread recipe might use honey and potato starch, a popular no-knead artisan bread recipe relies on the carbohydrates within the wheat flour.
The Role of Gluten
People new to gluten-free diets are often disappointed that they can’t find soft, fluffy breads. They flock to forums or to cashiers at health food stores, demanding to know where they can find products just like gluten-filled versions. The heartbreaking truth: they won’t find them. Gluten is the primary reason for traditional bread’s flavor and texture.
Found in products made wheat, rye, and barley, and in sub-species of wheat such as kamut, spelt, and triticale, gluten is the combination of the two proteins glutenin and gliadin. Water and mixing/kneading bind the proteins and work them into a visco-elastic substance which holds dough together. Gluten is so nutritious it is often extracted from the starch and used as a vegan protein or an additive in other low-protein foods. As a major component of these grains, it cannot be completely removed from bread flour. Vital wheat gluten is often recommended to people learning how to make whole wheat bread because it adds elasticity to an otherwise heavy product.
Mixing is crucial for gluten development. Recipes may require kneading for ten minutes to turn rough dough into a smooth substance that stretches into thin sheets. But too much mixing creates a tough product. Chewy breads such as baguettes require more kneading while soft sandwich breads involve less. Other factors controlling how gluten develops is types of flour used, the addition of other ingredients, how long it’s mixed and the method used, how much water, and what kind of leavening.
When gluten isn’t an option, breads rely on “gluten-replacers” to make products which don’t resemble hockey pucks. Xanthan gum, created from the fermentation of Xanthomonas campestris bacteria and sugar, binds flour together. Dough created with xanthan gum often creates a batter that must be poured into pans to give it shape. Psyllium, chia, and flax seeds also act as binders, producing dough that can be kneaded and shaped, but these products also contribute additional flavors and textures to the bread. Commercial gluten replacers may combine different flours, cellulose, gums, and emulsifiers.
Time and Temperature
Nothing delicious happens immediately. Time is critical for proper gluten formation as well as adequate leavening. Chemically leavened breads, such as biscuits and banana loaves, start rising immediately after ingredients are mixed. They can be poured into pans and slid into a hot oven to expand and bake. Though rapid rise yeasts are available, they don’t produce bread within minutes. Most recipes instruct a minimum of one hour rising time, then compression of the dough before it’s shaped into pans and risen again. This includes pizza crusts, dinner rolls, and some artisan loaves. Inadequate rising results in tough and chewy bread while allowing yeast to grow too long can cause the dough to overflow. Yeast doesn’t stop growing under the right conditions, so over-risen bread contains a strong and off-putting yeasty flavor and can upset sensitive stomachs.
A factor often overlooked by cooks learning how to make whole wheat bread is temperature. Yeast grows best in warm environments such as a hot and humid summer’s day. Beginning breadmakers may err by using water that is too cold or by letting the dough sit in a chilly room. Water and ambient temperatures should range between 85 and 110 degrees.
Heat kills yeast, which is necessary during the final baking stage. If extremely hot water is used, the yeast will immediately die. After properly made dough is set in the oven to bake, it will continue to rise for a few minutes until the product reaches a temperature high enough to kill the yeast and brown the crust.
Cooks learning how to make whole wheat bread should search for a highly rated recipe created by someone with an understanding of the science behind why it all works. After crafting several loaves and becoming familiar with the proper temperatures and textures, experienced bread makers may try interchanging flours, leavening, or flavorings to create new recipes. The best homemade bread recipes are recorded and passed down from kitchen to kitchen.
What’s your favorite bread recipe?
Originally published in 2016 and regularly vetted for accuracy.