I have celiac disease and must eat a gluten free diet.

I saw a recipe for creamy chicken and mushroom soup, and it looked delicious! However, it called for 1/4 cup all-purpose flour. Would it be better to use a 1 for 1 gluten free all purpose flour or use corn starch instead? If I used corn starch instead, I'm assuming I wouldn't use 1/4 cup....but how much SHOULD I use?

  • Hello Lisa, welcome and thank you for the question. Our goal is to have questions on specific problems posted here, and people who know the answer provide it, so everybody coming afterwards can learn the solution. This is why we don't allow users for asking for solutions to be sent to them via e-mail or other private channels. We also don't use signatures or "thank you", in order to make the whole more like an easily read reference source than a social occasion. This is why I removed your mail address and greetings.
    – rumtscho
    Jan 11, 2015 at 20:26
  • 1
    Can you post the recipe for us? There's a couple different ways to fix your problem, and knowing what else is going into the pot will help us figure-out the best method. Also, what sort of gluten free flour are you using?
    – john3103
    Jan 12, 2015 at 1:10
  • The thickening power of flour comes from the starch and not the protein, so from a food science standpoint this should be fine. Now what they did to remove the protein from the flour may alter the starch in such a way that some undesirable side effects may occur such as clumping/poor flavor, etc. If you want something with a good flavor and great thickening power, try oat flour (not all oat flour is gluten free, though, even though oats do not contain gluten.) Jan 12, 2015 at 17:03
  • 1
    Off-beat suggestions: Many "creamy" soups work fine if you base them on as-is rich coconut milk, without needing a thickener (or just with the slight thickening effect from potatoes in the soup. Never use cornstarch with coconut milk until you really know what you're doing) - look at the various tom kha variants or keralan vegetable stew :). If the soup can bear a tomato base - use the thickening effect of tomato concentrate. Jan 14, 2016 at 20:55

4 Answers 4


My step daughter also has celiacs/coeliacs disease. We often use all-purpose gluten free flour for soups, cheese sauce and roux etc. I can honestly say there is no noticeable difference. The only thing I would recommend is if the recipe asks you to make a roux don't try and cook out the flour as it will turn lumpy. Instead just melt the butter, add the flour mix it in then go straight in with the milk/cream (all of it, don't do a little at a time, as again it'll go lumpy) I'd stick to the same ratio (1:1) this time and then alter to your liking for next time.

You could by all means use just corn flour but if you want a thick soup and this is the only thickener you may end up with gloop instead. If you do use corn flour it's best to stir it in at the end, mix it with cold water then just add a table spoon of the mixture at a time until it's the right consistency.


There seems to be no clear definition for what "gluten free all purpose flour" is. If you look at two popular brand you will find that one of them is using rice flour, the other a legume flour as their main ingredient. These two ingredients behave very very differently - rice flour is a starchy affair that is good at making things crisp, legume flours are extremely protein heavy flours which often have strong enough binding properties to make them good egg substitutes. The rest of the mixtures... kind of look like a "broadband thickening" approach, like when you know you want something thickened but not which thickeners will work so you throw a tablespoon of every thickener within a five mile radius in the mixing bowl...

Such mixtures will not all behave the same when used out of their intended application, so unless we are talking a specific brand and product, results are not reliably predictable.


My go-to after cornstarch is potato starch, in the same measures as the recipe would use for cornstarch. Dissolve it first with twice the starch's volume of cold water.

If you don't mind the soup not being clear, oat flour is also a wonderful thickener, and it adds a hint of almost nutty flavor. Use in the same proportion as you would regular flours.

  • As it's a creamy soup anyway, you might be able to use a trick for thickening stews -- just grate a potato straight into the pot, and let it cook down.
    – Joe
    Mar 3, 2016 at 18:36

You can also use xanthan gum in soups as a thickener (but not 1:1 in substitution of flour). We use that in our keto diet.

Bob's Mill simple desciption


Personally I would not use a whole 1/4 cup of flour to thicken a soup. I would use heavy cream and/or blend a portion of the soup.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.