In the culinary arts, egg wash is a mixture of beaten eggs and some sort of liquid which is brushed onto food, such as pastry, before baking, to add shine and color.
If you've ever seen a pie with a golden, shiny glaze on the surface, it was probably created by brushing it with egg wash before baking.
Egg wash also helps give a golden brown sheen to soft bread like dinner rolls, danish pastry, cinnamon rolls, brioche, and challah.
Egg wash can also be used as a sort of glue to secure two edges of pastry together, as when making filled pastries, things like empanadas or other en route recipes. This works because of the protein in the egg coagulates when it's cooked, forming a stiff bond.
And if you want to sprinkle your pastry or bread with granulated sugar or whatever, brushing it with egg wash first will help the granules stick to the surface instead of spilling off.
As a matter of fact, you need to be careful with egg wash when you're working with puff pastry, because if it drips onto the edges of the pastry, it can glue the layers together, thus preventing the pastry from puffing while it bakes.
Also beware: If you don't wash your pastry brush immediately, you might find that you've glued the bristles of your pastry brush together, particularly if yours is made with natural bristles. Rinse your brush right away after using it, using cold water (because hot water will coagulate the egg), and once the egg is rinsed away, you can go ahead and wash it in warm or hot water.
By the way, I prefer to use a silicone pastry brush, because it's easier to clean, the bristles can't become glued together, and the silicone bristles don't absorb odors or fats the way natural bristles do. Nor do they shed their bristles the way natural bristle brushes do.
All right, let's get to the recipe!
Basic Egg Wash Recipe
- Crack an egg into a bowl and beat it thoroughly with a fork.
- Add 2 Tbsp of water and a pinch of salt, and stir until combined.
- Use a pastry brush to brush the egg wash onto the surface of your item.
That's it! You can use less liquid for a darker egg wash, or substitute milk or cream for the water. Alternately, some people use pure egg and don't even bother adding any liquid. This will produce a very dark shine.
Egg wash can be used on other foods besides just pastry. Duchesse potatoes are usually brushed with egg wash before baking.