To change the character of your bread, you can add other ingredients to the recipe's dough; one type is integrated into the structure and the other, after the dough structure has been formed. As a general rule, the less enrichments a dough has, such as added sugar, dairy and fat, typically, the longer the fermentation necessary because most of the flavor comes from the flour starches, which need time to release their natural sugars. Where enrichments are present, the flavor is derived from the enrichments rather than the flour, so a shorter fermentation time is preferable.
Some enrichments are "strengtheners or weakeners" or those that strengthen structure of the bread, such as whole eggs, milk and water or weaken or tenderize the dough, such as sugar, fat, egg yolks or acids (lemon juice). The other kind of enrichments, non-wheat flour and grains, and are added for interest and health to the recipe.
Fats and Oils Ingredients such as butter, margarine, shortening, nut, olive and vegetable oils are used to effect the level of moisture, the texture of the bread, to improve flavor and make bread tender. Fats and oils slow moisture loss, helping bread stay fresh longer and also help dough rise and increase volume. Adding fats and oils to dough makes the crumb more tender and the crust softer. Fat and oil are interchangeable; both produce the same effect on the crumb of the dough though the flavors vary greatly. Fat slows fermentation. Oily dough is heavier, which limits the stretch of the gluten and prevents large pockets of carbon dioxide from forming during fermentation. This is still relevant for gluten free bread, the binder (psyllium) is affected in the same way as gluten. The absence of large bubbles of gas results in the absence of large holes in the finished bread crumb. Bread with a tight crumb is preferred for recipes such as sandwiches.
Eggs help make the crust tender and add richness and protein. They provide color and flavor to breads. Some bread recipes call for them to be used as a wash for added color. Eggs added to dough help with rising because eggs are a leavening agent. As well, the fats from the yolk help to tenderize the crumb and lighten the texture. Eggs also contain the emulsifier lecithin which can add to the overall consistency of the loaf. Eggs, whole and yolks are added to the structure of the dough in the bread recipe and make it richer and add color. Egg whites however make a drier dough. Eggs are considered liquid ingredients so treat them as part of the liquid content and adjust the recipe accordingly.
Milk Replacing all or part of the water with milk will lend itself to a more tender, sweeter product. The sugar in milk, lactose, is not eaten by the yeast, so it is left to add a subtle sweetness to the finished bread. Milk also increases the nutritional value of the bread by adding additional proteins. A dough made with milk will brown more readily than one made with water. Milk helps to enrich the dough and the flavor of the bread. It produces a loaf with a creamy-colored, tender crumb and a golden crust.