An unfamiliar ingredient to most home bakers, lecithin is widely used in commercial baking. It's an emulsifier, an ingredient that helps other ingredients to mix more easily and remain mixed. Bakeries add lecithin to bread and other baked goods to improve doughs and batters, or to keep them from staling. It's also used in eggless baking, where it can replace the naturally occurring lecithin in egg yolks.
As a Dough Conditioner
Measure 1/2 to 1 teaspoon of lecithin granules for every cup of flour in a recipe.
Dissolve the lecithin in the liquid ingredients.
Prepare the baked goods as you normally would and bake them until done.
Taste and evaluate the finished goods. If their texture is not yet as improved as you'd like or if they still stale more quickly than you'd like, add more lecithin in the next batch. If the lecithin leaves a detectable flavor in the finished goods, reduce the quantity in your next batch.
In Eggless Baking
Dissolve 1 1/2 tablespoons of lecithin granules in 2 teaspoons of water for each egg yolk called for in a recipe.
Increase the water to 1 1/2 tablespoons if you're replacing a whole egg, rather than a yolk.
Add fat, flavorings, binding ingredients or leaveners as necessary to complement the lecithin and account for the eggs' other roles in your recipe (see Tips).