While some ingredients are undoubtedly easy to classify, others can leave you questioning their category, such as eggs.
In this blog post, we’ll answer whether eggs are considered wet or dry ingredients and explain their composition and function in baking.
Eggs are typically classified as wet ingredients in baking due to their high water content and their ability to add moisture, structure, and binding properties to baked goods. 1hey are composed of roughly 75% water and 25% dry matter, making them a significant source of hydration in baking. The exception to this rule is powdered eggs, which are considered dry ingredients due to their dehydrated nature and the need to mix them with liquid in recipes.
Defining Wet and Dry Ingredients
In baking, ingredients are categorized as either wet or dry based on their moisture content and physical characteristics.
Wet ingredients contain a significant amount of moisture. Common examples include liquids like water, milk, fruit juices, and components like eggs, and yogurt, which have a high moisture content and contribute to the hydration of doughs and batters. They also play a role in creating steam during baking, which helps with leavening and texture. Fats such as oil and butter also count as wet ingredients.
Dry ingredients, as the name suggests, are those that have minimal moisture content. Common dry ingredients include flour, sugar, baking powder, baking soda, salt, and spices. These ingredients provide structure, flavor, and leavening to baked goods.
The Composition of Eggs
The eggshell is the outermost layer, made of calcium carbonate, providing protection and structural integrity.
The egg white is a clear, viscous substance that surrounds the egg yolk. It contains about 90% water, making it a significant source of moisture. The egg white also contains proteins that contribute to the structure, texture, and binding properties in doughs and batters.
The egg yolk is rich in both proteins and fats. It contains emulsifiers like lecithin, which help create stable mixtures between liquids and fats, making yolks essential in emulsified products such as custards, mayonnaise, and certain cake batters.
Eggs as Wet Ingredients
Eggs possess a notable water content, constituting approximately 75% of their overall weight. This water content within eggs serves as a valuable source of moisture in baking, actively participating in hydrating dry components like flour, sugar, and leavening agents.
Hydration of Dry Ingredients
Eggs are composed mostly of water, making them one of the most moisture-rich ingredients commonly used in baking. This water content directly contributes to the overall hydration of the dough or batter when eggs are incorporated into a recipe.
The proteins present in eggs, particularly in the egg white (albumin), have water-attracting properties. These proteins have an affinity for water molecules, which means they can bind and hold onto water. When eggs are mixed with other dry ingredients like flour and sugar, the proteins help distribute and retain moisture evenly throughout the mixture.
Providing Moisture by Generating Steam
While the pastry undergoes the baking process, the water content in eggs undergoes a transformation into steam. The generated steam helps maintain a moisture-rich environment within the pastry, thereby preventing it from drying out during baking.
This moisture effectively keeps the pastries soft and fresh, preventing them from becoming dry and crumbly, and it also prolongs their shelf life while delaying the onset of staleness.
Wet ingredients help dissolve and release flavor compounds from the baking ingredients. For instance, sugars, salts, and certain flavor compounds are soluble in water. Moisture carries these flavors into the surrounding mixture, ensuring an even distribution of flavors.
Steam Participates in Leavening
As pastries containing eggs bake, the water content within the eggs evaporates, transforming into steam. This steam contributes to the pastries’ rise and tenderness during the baking process. Choux pastry and laminated doughs, such as croissants and puff pastry, rely partly or wholly on the steam generated within them for leavening and achieving their characteristic flakiness.
If you’re interested in learning more about the role of steam in leavening, I invite you to check out my article on the raising agent in puff pastry.
Additional Functions of Eggs in Baking
Eggs contribute more than just moisture to baked goods; they serve essential roles as emulsifiers, binding agents, and enhancers of color and flavor.
Eggs as Binding and Thickening Agents
Eggs serve as binding agents in baking due to their unique ability to hold ingredients together. This binding action is primarily attributed to the proteins found in eggs, particularly the proteins in the egg whites. These proteins form a network and coagulate during baking, providing both structure and stability to baked goods.
While preparing custards, creams, and fillings, egg yolks serve as thickeners by binding with water. In cheesecakes, eggs play a critical role in achieving a creamy and dense filling.
Eggs as Emulsifiers
Lecithin is a natural emulsifier found in egg yolks. It has a unique structure with one end that is attracted to water (hydrophilic) and another end that is attracted to fats (hydrophobic). This dual nature allows lecithin to create homogeneous mixtures of liquids and fats. Mayonnaise is a classic example of a recipe where eggs act as emulsifiers.
Eggs as Natural Coloring and Flavoring Agents
The egg yolk serves as a natural coloring agent, containing pigments that lend a rich yellow hue to baked goods. When used as an egg wash, it provides a glossy, golden-brown finish to the exterior of baked items. Eggs are also responsible for the distinctive creamy, custard-like flavor found in famous desserts such as Crema Catalana and Crème brûlée.
Conclusion
Eggs, with their composition of water, proteins, and fats, bring remarkable versatility to baking. They are considered wet ingredients due to their high water content, which contributes to moisture, tenderness, and binding. Simultaneously, eggs provide structure, emulsification, and stability to baked goods.
Eggs can also be considered dry ingredients when used in powdered form, which are valued for their long shelf life and convenience in various recipes.