I love gumbo, and make it about once or twice a month. However, I've noticed that my roux will occasionally separate from my stew and float up to the surface. I've sampled it, just to see if it had absorbed some of the flavors, but all I got was a floury taste.

I've had gumbo enough times to know that this shouldn't be happening - the roux should be enriching the flavor of the stew and mixing in, but it isn't.

A rough outline of what I do:

  1. Make roux with vegetable oil and flour in a 1:1 ratio.

  2. Mix in bell pepper, celery, and onions (aka "trinity"); stir frequently for 10-20 minutes.

  3. Mix in garlic, cayenne pepper; stir for two minutes.

  4. Mix in thyme, bay leaves, white wine; bring to boil.

  5. Add chicken, andouille, shrimp, tomatoes, clam juice, chicken broth; bring to boil and simmer for 30 minutes.

  6. Add okra; simmer for 10 minutes or until ready to serve.

Here's some thoughts on possible problems:

  1. I usually cook it in a slow cooker once I have all the ingredients simmering. I've only cooked it the conventional way (read: in a pot) once, and it didn't separate. (When I cooked it in the pot, some of the roux was in the stew that boiled off the top of the lid; a tasting revealed that it was more flavorful than the stew).

2. I've sometimes gotten lazy or been in a rush, so I only cook the trinity for 10 minutes instead of the full 20. (I've also noticed that the trinity gets uncomfortably slimy-looking after the 10 minutes, which has prompted me to prematurely move to the next step on a few occasions.)

And finally, an error I am not making: I am not burning the roux. It may smell smoky, but it is not burned.

Given this, what could be the cause?

EDIT: I've just made it again, and it's definitely not because I'm undercooking the trinity. Based on the evidence, I'm going to go with Sobachatina's answer, until I can try it again.

SOLUTION: Forgot to update this until I got pinged about a change on this question. The slow cooker made the roux separate from the gumbo; it has never separated from the stew when cooked in a pot, likely because the starch doesn't fully gelatinize when in the slow cooker. If anyone wants to look further and try to figure out when the starch is sufficiently gelatinized, drop a comment below with your result and I'll update this solution.

8 Answers 8


Making a roux has two purposes:

  1. Coat the flour granules with fat so they are able to dissolve into the cooking liquid without binding up.
  2. Cook the flour to remove the raw cereal flavor.

When the cooked, fat-covered, flour is introduced to boiling liquid the starch granules swell and explode tangling up the cooking liquid. The cooking liquid is thus thickened and delicious.

If your roux is separating then the starch has not gelatinized. Because you saw this problem in the slow cooker and not in a pot I suspect that you are simply not bringing your liquid to a full enough boil to gelatinize your starch.

I have never seen a roux separate out. The roux should dissolve into the cooking liquid. You might check your ratio and make sure that you don't have too much oil in your roux. Variability in measuring your flour might account for why you see this intermittently.

  • Interesting; I had no idea the roux gelatinizes until I read the Wikipedia entry on starch gelatinization. While a possibility, I don't think that this is the case, since I simmer my soup for 5 minutes before placing it in the slow cooker. I'd need to cook it again before making this conclusion, so it might take me a while to get back to this.
    – Edwin
    Commented May 26, 2012 at 17:50
  • 1
    I'm interested in hearing how it turns out for you. BTW, simmering is generally considered just below boiling or about 200F. Wheat starch gelatinizes at 212F. It is possible to simmer it all day and not have it thicken. Commented May 26, 2012 at 22:00
  • Really? I always bring it to boil, then just low enough to continue boiling. I hope that doesn't mean I've been cooking wrong all this time.
    – Edwin
    Commented May 26, 2012 at 22:11
  • No- that sounds correct. I just wanted to make sure that it actually came to a boil. Commented May 27, 2012 at 2:38
  • If it's a very low boil, then it's really only boiling at the bottom. The rest of the pot might be enough cooler that it doesn't work.
    – Cascabel
    Commented Jun 29, 2012 at 15:52

I cook gumbo all the time. I usually cook large gumbo for parties.. 30 quarts or greater at a time. I can tell you from experience exactly what is happening... And one of the answers above is right on. Your roux is not mixing due to a temperature issue.

I ALWAYS use 2 pots when making a gumbo... No matter what kind of gumbo it is. I use a cast iron skillet for the roux and a 30qt stock pot or bigger for the actual gumbo.

When I make the roux, I get the fat/flour mix to a chocolate color before cooling it with the trinity. Once I put the trinity in the roux, i stir and sit the roux for 5 - 10 minutes. It cools.

When I transfer to my stock, the stock has to be very hot... A rapid (roaring) boil. If not, the roux will never mix. The stock has to be hot enough for the flour to mix. The oil opened the flour using heat. If the stock isn't hot enough, the heated, open flour will cool and close on impact with the stock causing it to "separate". Once this happens, the roux is toast. Start spooning!

Make sure the temperature of the stock is very hot. Just because you see a boil doesn't mean anything. You need to stir the stock to make sure the boil isn't just from the bottom center of the pot (where the source of the heat is). Though you may see a boil in the middle, if is most likely from the bottom center and rising to the top (heat rises) leaving the sourounding stock below boiling. STIR. STIR. STIR the stock and make sure you have a RAPID boil around the stock and not just the middle. Once you add the roux, continue to stir making sure you don't let the cooler roux affect areas of the stock. Stirring constantly for 5 minutes of so will make sure you blend the roux with the entire stock as well.

I have also had this happen when using a stove or cookware that I was not familiar with. If you end up with a separated roux, spoon out what you can... Make a new roux and add this new roux back in. If the original roux was a dark roux, if will separate as a sheet and not break into granules that sink or are too small to fish out with a spoon. It will not hurt the gumbo. You basically are left with a stock or soup. Get the old roux out.... Boil that stock high... Add a new roux and go to town with the gumbo, chances are some of the original roux did mix well. Cleaning out what didn't mix and adding a new roux will surprise you how thick and flavorful the gumbo can be.

On a side note, the lighter the roux, the greater the roux will act as a thickening agent. The darker the roux, the less it thickens BUT the more it FLAVORS! I have actually intentionally made two rouxs for the same gumbo.... One for thickness and one for flavor. It's easy to screw up by having too much roux... But once you get used to doing it and learning where the right mix is, it can make for an amazing gumbo.


You might try doing the roux and chicken stock in a separate pan. Make the roux, and when it starts to turn golden (or dark brown - your choice), pour in a cup of stock and whisk continuously while adding. This will make a gravy like substance, to which you can add the rest of the stock to thin out to the correct consistency. There's really no reason to coat the vegetables in roux and the only reason the traditional recipe does so is so that you can get away with one pan.

  • I assumed that coating the vegetables in the roux was supposed to be a substitute for stir-frying or cooking the vegetables in oil, as well as help the vegetables soften up for the stew. I'd try your suggestion, but unfortunately I only have two pots which I could do this in, which I am using for the stew and rice, respectively.
    – Edwin
    Commented May 26, 2012 at 17:42

I usually have this same problem when I make a really big batch of gumbo. I've tried all of the usual stuff: adding cold stock to hot roux, hot stock to cold roux, doing an extra vigorous boil. None of it worked. I've come to believe the adding cold to hot trick is old kitchen lore that has no scientific foundation.

To settle this, I read some academic papers on the subject. My summary is below, but I highly suggest you read this article if you're interested in the subject.

To start, there are three ways to get oil and water to mix together.

  1. Vigorous mixing breaks up oil and water into tiny droplets that disperse through each other. Eventually, the droplets will eventually recombine with their like droplets until there's once again oil floating on top of water.
  2. Emulsifiers include ingredients like egg yolks and mustard. Emulsifiers are molecules that have one end that is attracted to oil and another end that is attracted to water. When oil and water are mixed together in the presence of an emulsifier, the tiny droplets are held together by the emulsifier. This prevents the droplets from recombining as quickly as in #1. One example of an emulsion is mayonnaise which is oil and vinegar emulsified with an egg yolk.
  3. Starches act as a thickening agent and thus get in the way of oil droplets trying to recombine.

Here's what you should do
If your oil is separating out then your roux didn't have enough thickening power. The flour loses its thickening power the longer you cook the roux. To make up for this loss you can add some additional raw flour after your roux has achieved a deep copper brown. This extra flour at the end will retain its thickening power, which will give you some additional insurance in preventing your roux from breaking.

For full disclosure I haven't tried this yet. I'm making gumbo later this week, so I'll try to report back. The paper I linked above has me convinced this will work though. I'll update this post later if I can remember.

  • You might also try techniques from making bechamel (another roux-thickened dish) .... add the liquid in increments, so you're basically thinning it out, rather than just combining the two and stirring. See cooking.stackexchange.com/a/4421/67
    – Joe
    Commented Mar 4, 2021 at 17:00

I've had my roux separate on more that one occasion and the cause I found was in the technique of adding cold stock to a hot roux, you have to temper your roux with the colder stock a little at a time, or you will end up shocking the oil and flour and the roux will separate from the stock liquid. I found the remedy to this; Oh shet moment on a Cajun cooking website that saved the day, and it was a pretty easy fix, just crank up the heat and continue to stir your gumbo until the stock and roux reach a temperature where they come back together.


Although I am not from Louisiana, I have made gumbo dozens of time and live in the New Orleans area, I had my roux separate twice. Tonight was the second time. I found a fix on another web page. I used Xanthan gum which is an emulsifier. It bonded the roux to the stock. However I used too much and now my gumbo is extra thick. Make a slurry with it first and then add to the gumbo and it will pull it together. It doesn't need much. it may be hard to find though. i found it at a larger grocery store with the gluten free foods and the health food.


You must temper your roux. Hot roux likes cold stock, cold roux likes hot stock.

  • 4
    And why is that?
    – lemontwist
    Commented Dec 27, 2012 at 5:59
  • 4
    On Christmas day I made a sauce using hot stock and a hot roux. Today I used the same stock, but cold from the refrigerator. The sauce made with a cold stock took a little longer, but the end results were near-enough identical. I don't think that this is the answer. Commented Dec 27, 2012 at 20:28

Not cooked enough. Boil it an additional 15 minutes on the stove top. I always use unbleached all-purpose flour. Good-Luck!

Chef Bourque'

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