One of the things I love about cooking is the mystery, how a handful of unrelated ingredients merge and create a new, wonderful thing. Oil + Vinegar = Vinaigrette. Cream + Melted Chocolate = Ganache. Flour + fat = roux.
A roux is a thickener, equal amounts (give or take) of fat and flour whisked and cooked together to produce a powerful paste full of starch that will give your sauces, soups, stews and gravies just the right consistency. If you’ve ever made a bechamel sauce, gravy or gumbo, you’ve likely made a roux.
How to Make a Roux
Most roux are made by whisking flour into melted butter over low heat, but you can also use the fat rendered by frying bacon (remove the bacon from the pan before adding the flour) or oil in place of the butter. Once the flour’s added it’s time for some serious whisking to make sure the fat and flour combine well, but also to keep the roux moving in the pan. Both flour and butter burn quickly and easily and a vigorous whisking allows them to cook gradually without burning (burnt flour taste = yuck). It’s important to let your roux cook for at least a minute or so to cook the flour so your dish won’t taste like, well, uncooked flour.
There are three distinct stages or types of roux. White roux is what you should have after whisking the flour and butter together for about a minute. It should be thick, white in color and should be pretty tasteless in your finished dish. Cook it a little longer — keep whisking — and you’ll have a blond roux, a slightly thinner mixture with a slight yellow tinge. A few minutes more and you’ll have a brown roux, a thin, brown mix that will give foods a nutty flavor.
What’s the difference, besides the color, consistency and taste? Well, the longer you cook a roux, the less thickening power it’s going to have. White roux are usually added to sauces and such that you want to be extra thick or creamy while brown roux are most often used to stews or gumbos.
Did someone mention gumbo? Because I have a terrific recipe for Shrimp & Andouille Sausage Gumbo, that’s made with — you guessed it — a roux. Get this on your Mardi Gras table immediately!
Whisk CONSTANTLY once you add the flour. You have to keep it moving to prevent it from burning.
If you burn your roux (it happens, don’t sweat it), start over. If you power thru your gumbo will taste only of burnt flour.