Egg wash: Goal browning and shine. Sour cream: Best browning, high gloss (outshined the egg) Heavy cream: Light browning, a slight shine. Whole milk: Well-browned, slight shine ...

What is an egg wash? "It's essentially a filter for your baked goods," says food historian and baker KC Hysmith. "It's a really simple thing that most bakers should learn to enhance their baked goods.

When egg wash is used as a topping (as opposed to a binder), its primary function is to impart color, shine, and leave no trace of flavor, so that's what I was looking for.