With Roux My Heart is Laden

When I was 12 my mother let me help her make the gravy for frikedeller¹. After pouring off most of the grease from the Teflon lined avocado green electric skillet that she had fried the meatballs in she added some butter and let it sizzle until the foam subsided. She then sprinkled on some flour and let me stir the mixture with a flat whisk until the flour had absorbed all of the fat and just began to turn brown. When she poured in some water that had been flavored with a bullion cube I watched in amazement as the butter soaked flour violently expanded like whipped cream from a gas dispenser. Once the first bit of moisture hit it, the hot fat and flour seemed to angrily search out more, absorbing every bit of liquid it could find, calming only when enough liquid had been added to form a smooth viscous liquid. I know we ended up with gravy. What I didn't know at the time is that we began with a roux.

Roux, simply defined as wheat flour cooked in some fat, has been used to thicken liquid for gravies and sauces for over 500 years². In classical French cuisine roux is broken down into three basic styles: white, blonde and brown. The difference among the rouxs is simply a matter of cooking time, with the roux getting darker the longer it cooks before liquid is added. Each of these styles of roux serve as the primary thickening agent for three of the five mother sauces³: white roux for béchamel or white sauce, blonde roux for velouté or yellow sauce, and brown roux for espagnole, or brown sauce.

Until the 1980s, the culinary intelligentsia of the United States only considered roux within the context of thickening sauces. Indeed, in his seminal work American Cookery, James Beard only considered brown roux in terms of Brown Sauce. And even there he instructs the reader to brown the flour in an oven before adding it to the oil. In reality, the roux dial was turned up to 11 in the 18th century by the Acadian exiles in Louisiana who transformed roux from a thickening agent into a source of incomparable complex flavor. The Cajuns discovered that cooking roux past brown, almost to a dark chocolate color, added rich nutty, almost smokey essences to a dish. The darker the roux, the more flavor it brings to the party. Unfortunately, the darker the roux, the less it's ability to thickening anything. But darn it, it's easy enough to add a little blonde roux to thicken things up at the end, now, isn't it?

Roux works as an efficient thickening agent by allowing for the uniform dispersal of the flour's starch granules throughout a liquid before the liquid, heat and starch can get together and do their thing. The fat is important because it helps keep the starch granules separate (if you dump flour or starch into a hot liquid, you'll only end up with gelatinized lumps floating in liquid—a good thing for dumplings, but not for gravy). Thickening happens as heat melts away the protective fat coating, the starch granules absorb water, swelling, with some of them eventually bursting, releasing amylose molecules that bond with the water and form a wonderful web that restrict the free movement of the remaining gelatinized starch granules⁴. Swollen starch granules that can't move mean thick gravy. Now, the more you heat the sauce or gravy, the more starch granules will burst, and eventually the liquid will thin out. Dark roux has limited thickening power for similar reasons. The heat of the oil breaks up the starch granules before they ever have a chance to swell by coming into contact with liquid⁵.

The temperature of both the roux and liquid are important considerations when transforming thickening rouxs into gravy or sauce. It's a lot easier to spread all the little fat coated starchy flour granules throughout the liquid before the thickening action really kicks in if the fat is relatively solid (but not rock hard straight from the refrigerator solid) as you start to whisk the roux and liquid together. If both the roux and liquid are hot, chances are the fat will melt from the starch granules before you've distributed them evenly, resulting in clumps of flour and pools of fat⁶. If both the roux and liquid are cool, well, you're just jousting with windmills as the roux will never disperse evenly without the aid of an immersion blender or a Merc 225. You'll find the greatest success when whisking the cool ingredient (again, that's room temperature cool, not refrigerator cool) into the hot ingredient.

For the most part, light rouxs call for either butter or some of whatever fat has rendered from whatever you are cooking. Fat selection is much more important in dark rouxs though. This is partly due to the cooking time and temperature required to make a dark roux⁷, but mostly it's due to flavor. Duck fat, bacon fat, peanut oil, canola oil, lard—they all bring different flavors to the roux and the finished dish.

The ideal proportions for a roux, whether for thickening or flavoring, are roughly equal volumes of flour to fat. In most cases you want about 15% to 25% more flour than fat to improve the thickening power of the roux. To make a pan gravy or a white sauce for four people, adding two cups of broth or milk to two heaping tablespoons (scoop with a tablespoon measure and dump it in without leveling) of flour cooked in two tablespoons of fat will do you just fine. If you're making a cup of roux for a gallon of gumbo, however, you'll want a 1–1/4 cups of flour to a cup of oil.

The biggest challenge people have with a roux is keeping it from burning, while still cooking it enough to get rid of the cereal flavor of raw flour. If you let flour and fat sit in a hot pan for even a minute, there's a good chance the flour will begin to burn. And, just one spec of burnt flour will ruin whatever you plan to make with it. The obvious solution, is to pay close attention to the roux, stir it constantly so that no single flour granule spends enough time on the hot pan bottom to burn, and cook the roux over a burner at it's lowest setting, allowing you to easily stop the cooking process before things go too far. For a white or blonde roux, this means ten to twenty minutes of constant stirring and close attention—not that big a deal. But for brown rouxs, and especially dark Cajun rouxs, you could be talking about over an hour of standing at a stove stirring and stirring and stirring.

To make a dark Cajun roux, Paul Prudhomme recommends adding the flour to oil heated to it's smoking point over a burner set as high as it can go and whisking like mad when you add the flour. This method will indeed brown the flour very quickly and you can end up with a wonderful dark roux in a matter of minutes. Of course, Paul Prudhomme has fair amount of experience making roux. He can whisk faster than most of us can ever hope to and he knows almost intuitively when good roux goes bad. My one and only attempt at this method, however, resulted in a neighbor calling the fire department. In my experience, you only improve your margin of error by lowering the heat, and simply taking more time to stir and cook the roux. My first successes with darker rouxs began by cooking them over a burner set between low and medium–low. Yep, it did take as much as an hour to get the roux to just a dark peanut butter color. But, I had complete control over the cooking at all time. Though now I confidently set the burner to medium–high heat and need only thirty minutes to get to a nice dark milk chocolate color roux, the experience of watching the flour and fat cook over low heat and watching how the roux changed was invaluable.

Before you begin to add the rest of your ingredients your piping hot roux, keep in mind, that roux can be a force for bad as well as good. In Paul Prudhomme's Louisiana Kitchen, Chef Prudhomme calls dark roux Cajun Napalm, a wonderful nomme de guerre, recognizing that flour is perhaps the ideal vehicle for delivering hot oil to warm flesh and getting it to stay there. Common sense tells us to add stock or vegetables to the bubbling goo a little bit at a time and from as great a distance as possible to avoid getting hit. Common sense, however is wrong. If you think about it, by increasing the number of times you add something to the pan you're not reducing the risk of splatter as much as increasing the opportunity to be splattered. And increasing the distance from which you add the ingredients only increases the size of the splash made when they hit the pan (think pools, 12 year old boys and “the cannon ball”). A better way⁸ to avoid being splattered with the domestic equivalent of hot lava is to add all of your ingredients to the roux at once and add them as close down to the pan as possible. Adding the ingredients all at once both reduces the statistical chance that you'll have to take a hit for your guests and rapidly reduces the temperature of both the pan and the roux if you do.

1. Frikadeller are traditional Danish meatballs made of equal parts ground veal and pork mixed together with chopped onion, breadcrumbs and egg.
2. Most sources date the use of roux to the early to mid 17th century based it's appearance in a 1652 cookbook “Le Cuisinier Francios Francois” by Pierre de La Varenne, a court chef during the reign of King Louis XIV. Of course, most culinary historians don't appear to believe that a cooking technique has been invented until it's invented in France. Meanwhile, a century before in Germany, Sabina Welserin provides the following direction for making yellow sauce for game or birds: “First put fat in a pan and fry some flour in it, then take some wine and three times as much of broth and put it into the pan and add to it ginger and pepper and color it yellow, then it is ready.” In On Food and Cooking Harold McGee points to evidence of an even earlier origin documented by Italian chef Giuliano Bugialli in one of his cookbooks with a reproduction of a 15th century Italian manuscript describing flour browned in fat. Before roux, adding bread or breadcrumbs was the primary method to thicken soups and sauces.
3. There are four mother sauces defined by Careme: Béchamel, Velouté, Espagnole and Hollandaise. Escoffier adds a fifth: Tomato.
4. Harold McGee, On Food and Cooking, pp 334–339
5. Shirley Corriher, CookWise: The Hows and Whys of Successful Cooking, p277
6. Having the roux and liquid at different temperatures isn't critical, but is does make things easier, if just a little more time consuming. When cool liquid hits a hot roux the fat congeals, preventing too much liquid from reaching the starch granules before you get a chance to disperse them. If you're good at whisking fast, though, you should have no problem successfully combining warm liquid and roux and cutting down on your cooking time.
7. If you're using butter for a dark roux you'll want to clarify it. The solids in non-clarified butter will burn before the flour colors, ruining the roux.
8. As recommended by Shirley Corriher in CookWise