A roux, by any means?

A techniques question for the cooks.

I have made roux.

I have also followed recipes that say to sprinkle flour on the food cooking in the pan, stir and cook for a bit, then slowly add broth or milk. Similar effect... a thickened, opaque sauce happens.

Recently, I made a pot pie recipe that bade me add the flour to the milk/cream in a measuring cup and let them sit a while. Sludge ensues, which you add to the food cooking in the pan. Similar effect... sauce.

So, now the question: Why all the different techniques? Is there more to it than just being pragmatic (e.g., the sauce can't always come first)? I suppose a roux can get browner than the others, and that third one is very little cooked, but I'm still wondering.

[Robin Garr]

They're all legitimate ways to use flour as a thickener, Jeff. If you're talking Cajun-Creole, though (cue recent Paul Prudhomme thread), then the element of browning (red, brown, black) that occurs during the first stage becomes a key flavor contributor. You don't get that with a flour-liquid slurry or sprinkling the flour directly onto the cooking food.

For thickening with flavor in mind it's hard to beat a roux. But for the usual slurry, I just made a stew that called for a simple technique that never occurred to me. Pour your water into a sealable container, add the flour and shake like hell. Then pour into your dish and carry on.

As Robin said, dark roux is a key flavoring element in some Cajun and Creole dishes. That aside, the different thickening-with-starch techniques have different characteristics, particularly regarding how well they hold up if the food has to sit around vs. being consumed immediately. Julia Child has a good discussion of this in her book The Way To Cook.

-Paul W.

You will also notice that there is a difference in thickening quality depending on the handling of the flour. Flour and liquid made into a slurry and added to your recipe will have greater thickening ability quicker than a roux that has been cooked fo a while before adding. And, as everyone else has said, there is a distinct flavor difference. I believe all flour needs to be "tamed" with a little precooking in order to loose that pasty taste unless it's included in a long, slow cook recipe.

[Jenise]

Jo Ann covered essentially the answers I would give. You start with a roux when you have to bring in fat to get started--like butter or oil. If you're making a béchamel, you have an empty pan. But if you've fried pork chops, say, and you want to make a gravy? The fat and browned bits (known as the fond) are in the pan, and adding the flour and liquid together (best way what Fred said, forget about that little cup--you'll get lumps unless you have a tiny whisk), because the initial liquid-that-has-not-yet-thickened, as it comes to a boil, helps release the brown bits that are going to seriously flavor your gravy. You also get a sauce that tastes good right away, though further simmering improves it.

Thanks for the good discussion, everyone.

If I am cooking the roux a bit, I am fine with that route, but if I just want to thicken and have a nice clear sauce, nothing beats arrowroot - no need to make a roux, just add it from a sifter (less chance of lumps than doing that with regular flour). Better than cornstarch whether made into a roux or just added.

Anyone else use it much?