An egg wash is usually a mix of beaten egg, egg and milk or egg and water brushed onto baked goods such as pies, Calzones, sausage rolls, and tarts such as Linzertorte to give a golden-brown finish when cooked. Egg wash can also be used to stick foodstuffs such as nuts and seeds to bread and pastries and to seal pastry edges when making items like pasties.
For medium-sized egg use three to four tablespoons of liquid. If you use more egg the finished bake will be darker. Vegans can use vegetable oil or a mix of corn syrup and water to achieve similar results.