Gluten, starch, yeast

Gluten is a naturally occurring network, or 'mesh,' structure of proteins found in various grains. It can be described as a springy, stretchy net that provides flour-based foods with their unique characteristics, such as the chewy, airy texture of pizza crusts, the tender yet firm al dente bite of pasta, and even the soft, crumbly quality of freshly baked cookies.

In simple terms, gluten forms when the flour of certain grains comes into contact with water. More specifically, rye, barley, wheat, and wheat derivatives contain a pair of proteins called glutenin and gliadin. When these proteins are exposed to water, or a liquid containing water, a chemical reaction occurs, leading to the development of gluten.

gluten potential & development.

The gluten potential of a flour is determined by the type of flour used. Flour with higher protein content will have greater gluten development and create a stronger dough. For breads and baked goods that require a chewier texture and greater gluten development, higher-protein bread flour is used. For lighter pastries and cakes, cake flour is used, which tends to have lower levels of protein.

Gluten development occurs when flour is mixed with water and the proteins, glutenin and gliadin, become hydrated. These proteins are responsible for giving dough its elastic and extensible properties. When the dough is mixed or kneaded, the proteins in the flour form long chains that begin to align and cross-link with each other, creating a strong, elastic structure. This is also called a gluten "network" or a "matrix." The amount of gluten development depends on several factors, including the type of flour used, the amount of water added, and the length of time the dough is mixed or kneaded. The addition of salt will also strengthen gluten, while adding fats will cause gluten to weaken or "shorten."

glutenin.

gliadin.

Starch is a complex carbohydrate that consists of chains of monosaccharides (glucose) that are linked together through chemical bonds. In the bread baking process, the flour we use plays a crucial role, as it is mainly starch; contributing to texture, flavor and even shelf life.

When flour mixes with water, a process known as gelatinization begins. In this process, starch granules in the flour start swelling as they absorb water. Importantly, it aids in gluten development by behaving as support beams for gluten networks to be held and prevents over-development of gluten.

During baking; the starch in the dough continues to absorb water and swell. This is crucial in giving baked goods their structure. During this phase, the gluten networks break down and release water, which is then absorbed by the starch. The starch eventually bursts due to the heat, forming a gel-like structure that retains water. This unique structure contributes to keeping the baked goods moist even after the baking process is complete.

Starch also provides food for the yeast. As the dough ferments, enzymes break down starches into simple sugars which provide food for yeast and contributes to the development of flavor of the bread.

the Maillard reaction.

The Maillard reaction is a complex chemical process that occurs when amino acids and carbohydrates, such as reducing sugars like glucose, are heated to a temperature of around 280°F (138°C), alongside a multitude of other chemical reactions. This is the reason why foods become brown in color when heated and what provides foods with many of the unique flavors and aromas we experience. It is important to note that this is not to be confused with caramelization, which occurs when only sugar is found in food.

The Maillard reaction is responsible for countless numbers of flavors, textures, aromas, and colors in the foods we eat. For example, think about the nutty, rich aroma of brown butter, the caramelized, crispy crust of a freshly baked bien cuit sourdough loaf, and even the roasted flavors on the crust of a perfectly-seared steak.

As humans, the Maillard reaction attracts us at an evolutionary level. Essentially, the aroma or even the idea of a browned, crispy, seared piece of meat signals to our brains that what we are about to consume contains easily digestable nutrients and is most likely safe to eat as the food is cooked. This is similar to when our mouths begin to salivate at the thought or sight of food when we are hungry.

what is starch?

20-billion yeast cells weigh in to roughly one gram.

what is yeast?

Yeast is a single-cell organism that belongs to the fungi kingdom. It exists all around us, on our bodies, in the air, and even on the surface you may be reading this on. The yeast that we use most often today is known as Saccharomyces Cerevisiae, also known as brewer’s yeast. Yeast serves its purpose as a leavening agent. By consuming and breaking down the large starch molecules found in flour into simple sugars, the yeast creates carbon dioxide gas and ethyl alcohol as by-products. With no place to go in the dough, the gas rises, which in turn aerates the dough and provides lift, creating something like a balloon. The gas created by the yeast creates thousands of CO2 bubbles in the dough, which turn into air pockets in the bread when baked, providing a desirable airy and light texture.

Besides contributing to the rise of bread, yeast also plays a crucial role in developing flavor. During the fermentation process, various chemical reactions occur, resulting in the production of compounds that affect the sensory qualities of bread, such as appearance, aroma, flavor, and texture. One key compound produced during fermentation is alcohol. Yeast creates ethanol, which adds to the flavor and aroma of bread. Generally, longer fermentation processes lead to more complex flavors, as the yeast produces additional aromatic compounds like esters and aldehydes, which contribute to the sweet, fruity, and buttery notes found in various types of bread, especially sourdough or naturally leavened breads.