Recently I made roux for gumbo using bacon fat instead of lard. The roux ended up a greyish brown and it didn’t look very appetizing, though the gumbo tasted fine. Is there anything I could’ve done differently?

Roux was traditionally made with animal fat, according to Paul Prudhomme in his book Louisiana Kitchen, and it’s now mostly made with oil. Well, I hope he left that trend back in the 1980’s when he wrote the book, because animal fat makes a tastier and more healthful roux. But whatever fat/oil you’re using, the general rules are the same.

Using a ratio of one part each of fat and flour, you begin by heating the fat. Once it’s hot, you sprinkle in the flour a little at a time, stirring or whisking continuously. I prefer a whisk; it breaks up any lumps better. From then on, it’s a matter of how long you cook the roux before adding other ingredients.

White roux cooks only enough to eliminate the taste of the raw flour, about two or three minutes. Blonde roux cooks a little longer, about five minutes, and should be a light golden color, barely darker than the color of flour. Brown roux is cooked the longest, until it becomes, well, brown. And a true Cajun roux, unlike a traditional French brown roux used for brown sauce, is an even deeper color. It’s not easy to make until you’ve practiced quite a bit, because of the tendency to cook it too quickly and burn it. Burned roux tastes nasty and will ruin any dish it’s put in. Nor will it provide any thickening power, because the longer flour cooks the more that decreases.

None of these rouxs ever takes on a greyish cast, however. They go from white to blonde to brown to a deep chocolate color. So why yours did is difficult to determine. The only thing I can think of is that if you made it in a cast iron skillet, perhaps the skillet wasn’t seasoned and some of the iron scraped off into the roux. The same could also happen if you used an aluminum pan, aluminum being a soft metal and easily scratched.

When polled, one of my chef friends wondered what kind of bacon fat was used. Perhaps if it was a flavored bacon, there may have been some kind of cure that would cause the discoloration. Sorry, but without having seen the ingredients you used and how you went about making the roux, those are the only two possibilities I can come up with. Let me know if you think either may have been the case.