Since the simplest things can often cause great confusion it seems well worth doing a proper tutorial on the subject of egg wash. I should say straight out that while I am aware of all the possible additions to an egg wash, I’m not a big believer in the benefits of that alchemy. Unless you’re very much into the minute details of presentation — and I’m clearly not — a simple wash made of well-beaten whole egg plus a dash of salt will do you for most any job. Multi-ingredient washes made from egg, cream, water with a dash of sugar…homey don’t play dat. Here’s what I do: crack an egg.
Give it a swizzle.
Mix in a couple sprinklings of salt.
What will this do aside from seasoning it? Good question. It will cause the mixture of liquid yolk and semi-gelatinous white to relax into an even, water-like solution. How? Well you’ll recall what I’ve written before about egg white proteins. In their natural state they occur in little bunches scattered throughout the white. Well I suppose I shouldn’t say “scattered” exactly, since the fresher the egg white is the more those little bunches are attracted to each other. They end up clustered together and it’s this clustering that makes a very fresh egg white thick and even a little milky in color as all those clustered protein bunches bounce light rays back to our eyes.
Add salt and that situation changes. The protein bunches aren’t nearly so attracted and in fact start to repel each other a little. Something like this happens as an egg gets older and the pH of the white naturally starts to rise. The little protein bunches spread out, making the white both thinner and clearer. But I digress. After about ten minutes I return to my egg wash which has thinned considerably as the protein bunches pushed away from each other. It has also darkened considerably. Don’t ask me why, I don’t know. What am I, some sort of encyclopedia or something?
Perfecto. Smooth and even, ready for painting on without glops.
I should add that you don’t want to fall into the trap of thinking that if a little bit of salt in the wash is good, a lot must be even better. Don’t go adding half a teaspoon or something crazy like that since too much salinity has the reverse effect on the proteins, causing them coagulate. You don’t want that since it means curds and blobs of egg all over your buns. Or Danishes…whatever you happen to be doing. All clear?