The question—from a young cook—caught me off guard. I haven’t had a kitchen without a pastry brush (or two) in the drawer since forever. Even when I was 22, living in Paris, with a kitchen-in-the-corner-of-the-hallway, there was a pastry brush in the (only) drawer.
If you bake, you need at least one pastry brush. If it is a boar’s bristle brush, it should be dedicated to pastry and not shared with your barbecue tools or allowed to wallow in garlicky or other savory marinades.
More: Make these doughnuts! (They're Amanda Hesser's pistachio-cardamom ones.)
You need a pastry brush because nothing is better for applying a very thin-but-thorough and even coat of something wet or gooey or sticky—egg wash, cream, hot fruit glaze, melted butter, even water. A good brush can safely navigate all kinds of surfaces, be they porous, flaky, crumbly, delicate, moist, or dry. A good brush holds a lot of goop but gives you enough control to put it exactly where you want it, neatly and evenly, without unsightly drips—or pooled drips that can inhibit the rise of a biscuit or layers of puff pastry. A good brush is quick and efficient to work with, and as accurate as you want it to be.
If you are new to pastry brushes, I recommend old school boar’s bristle (but not nylon) brushes. They work perfectly and they are versatile. If you buy them online, or in a hardware or art supply store or commercial kitchen supply, they cost very little and you can justify more than one size—my go-to brushes are 1 inch and 1 1/2 inches wide. None of us like to clean boar’s bristles, but we get over it! Silicone brushes cost more but they are seductively easy to clean. The tricky thing about silicone is that there are too many different styles (not just sizes) to choose from, and many don’t work as well as boar’s bristles for pastry applications.
If you do choose a silicone brush for pastry, those with very thin, round (rather than flat) silicone "bristles" offer the most control and precision. (Silicone brushes with flat, ribbon-shaped bristles are better for sloshing a bunch of marinade on a steak rather than applying thin even coats of glaze or egg wash.) Le Creuset makes a 1-inch silicone brush with very thin "bristles" (each about 1/32 inches in diameter!) that works about as well as my 1-inch boar’s bristle brush; unfortunately the next size up (2 inches wide) has thicker silicone bristles instead of more thin ones—what were they thinking!—and it doesn’t work as well. I get grumpy about such things.
Anyway, once it or they are in your drawer, here are just a few of the things you will do quite easily in the future:
Have pastry brushes been indispensable to you? Or are you a seasoned baker sans brush? Tell us in the comments.