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Can I make a flour slurry to thicken soup?

Hi. I plan on making a cream of artichoke soup. Since it already has cream in it, I would rather not add additional fat like what a roux would add. Can I make a slurry out of flour like I do with cornstarch? I usually use cornstarch but have learned from chowhound that flour is more heat and freezer stable.

Thanks for your tips and advice.

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  1. Yes, you can. I often do this when making creem of vegetable soups that I don't want to add any dairy in order to stabilize the emulsion. The important thing is to bring it up to a full boil to make sure that the flour is fully cooked otherwise there's a raw flour taste. So it's easier to control if you add the slurry and cook it before you add your cream.

    1. Potato starch works better (a Jacques Pepin recommendation). And an old Julia Child trick: if you blend the broth, the artichoke and cooked white rice, you thicken the soup and don't need to use much (if any) cream.

      1. Yes. You can mix the flour with water, broth, or the cream.
        Make sure there are no lumps, then drizzle it slowly into the simmering soup, stirring, and pull off heat once it begins to thicken, as it will continue to do so off the burner.

        A canister of Wondra flour, which is made in such a way as to pour smoothly and not clump, is a worthwhile investment for making sauces, gravies, and soups.

        1 Reply
        1. I like to add some of the soup to the slurry and then add it all back to the pot. I know there's a name for that but it escapes me.

          1 Reply
          1. Agree with the suggestion of Penthouse Pup using potato starch to thicken soup, roux, and stew, rather than flour.

            You can make your own by shredding a potato, or taking cut up pieces and spinning the starch out to save. Even potato peels will emit some starch when spun. I used the hand-powered tool in the photo, specifically the black basket insert to spin potato starch out of potato cuttings.

            It takes 30 seconds to spin, and stores in the fridge for a week or so. Just a little goes a long way.

            1. Sure! As long as nobody at the table has a gluten problem.

              2 Replies
              1. re: John Francis

                Can use a pinch of xanthan gum. It's a tremendous thickener emulsifier. Work in hot or cold

                1. re: John Francis

                  True, as it is with other allergies.

                2. If you use flour, make sure it gets thoroughly cooked! I had too many raw-flour-in-the-gravy experiences as a kid...

                  1. I've used leftover or even instant mashed potatoes to thicken soup.

                    1. Thank you to everyone who replied. I will try blending some of the artichoke and adjust from there.

                      1. I was once taught that you use half as much corn starch than flour to thicken and half as much something else (I believe it was another thickener than corn starch. I just mix it with a little cold liquid and add it to the soup you wish to thicken it will thicken anything up as it cooks. By the way I thought all American cheese was a processed product. Am I wrong? I just got off another thread and wish to remind everyone that when it comes to food, we all have individual tastes and preferences. What is great for one person may be strange to another. Neither is right or wrong.Just different;

                        1. I am a big fan of using super-pureed cauliflower to make a creamy soup. This <a href="http://thehealthyfoodie.com/2013/02/1... chicken soup</a> is like the inside of a pot pie.

                          1. Cooked white rice is my go-to thickener especially for tomato basil soup. After it's pureed you will swear it has heavy cream in it.
                            My mom's secret to heavenly potato soup is adding some instant mashed potato flakes. Just the cheap ones you get in a little pouch for less than a dollar. Sprinkle in before serving and stir til they disappear.

                            2 Replies
                            1. re: ChefKaren

                              I buy exactly one of those $1 pouches of instant potatoes a year, just for soup thickening! I've tried pureeing real potatoes, but doesn't work quite as well as the fake stuff.

                              1. re: ChefKaren

                                That's the ticket! ..... I use instant mashed potato flakes to thicken all soups & most sauces. It does NOT affect the flavor at all & thickens consistently, no matter how much fat is present. And it doesn't get watered down when refrigerated or cooled. Just what everyone needs!

                              2. To avoid raw flour taste, you can use a so-called "Oil-Less Roux" as described by John Folse here: http://www.jfolse.com/fr_rouxs.htm

                                1. while one can certainly use a variety of thickeners, I prefer to add some rice or potato, or to puree the soup to desired thickness with a stick blender. I would think artichoke would thicken nicely.