If you’re out of flour, you can still make a roux using other ingredients like cornstarch, rice flour, almond flour, arrowroot powder, tapioca flour, or even coconut flour. Each one works a little differently, but they can all help thicken sauces, soups, and gravies.
Cornstarch is the easiest swap. Mix it with cold water to make a smooth slurry, then stir it into your hot liquid. Arrowroot powder and tapioca flour work the same way and give sauces a glossy finish. Rice flour is great if you want something close to regular flour. It blends well with butter and thickens smoothly.
If you’re eating low-carb, almond flour is a solid choice. It adds a slight nutty flavor and works best in creamy sauces. Coconut flour also thickens well but soaks up a lot of liquid fast, so use a small amount.
No matter what you use, just keep stirring and watch the heat so things don’t burn or clump. With a little trial and error, these swaps can save your dish and still give you a smooth, tasty result. Try one out next time you’re cooking and see which one works best for your recipe.
Can I make a roux with cornstarch instead of flour?
Ever start a recipe and realize you’re out of flour right when you’re about to make a roux? Yeah, I’ve been there too and it’s frustrating. A roux is the base of so many good sauces, from creamy mac and cheese to hearty gumbo. But here’s the good news: you don’t always need flour to make it work.
In fact, there are plenty of simple, tasty substitutes that can get the job done. Some even work better than flour, depending on what you’re making. Whether you’re avoiding gluten, cutting carbs, or just improvising with what’s in your pantry, this guide has your back.
Let’s dive into some easy, practical flour swaps for roux that actually work and I’ll share some cooking tips I’ve learned the hard way!
Why Use a Roux in Cooking?
A roux is one of those cooking basics that shows up in all kinds of recipes, but not everyone knows why it’s so important. A roux is just a mix of fat and flour that gets cooked together. Sounds simple, right? But that little mix can make a big difference. When you cook flour in fat, it changes the flavor and helps thicken things like sauces, soups, and gravies.
I remember the first time I made mac and cheese from scratch. I didn’t make a roux, and the cheese sauce turned out grainy and thin. Later, I learned that starting with a good roux makes the sauce creamy and smooth. That was a total game-changer for me. Once I understood what the roux was doing, it made all my sauces better.
Roux also helps blend everything together. Without it, sauces can feel watery or separate. Depending on how long you cook it, a roux can also give your dish a deeper color and richer taste. There’s a light roux for white sauces and a dark roux for bold dishes like gumbo. So even though it’s just two ingredients, a roux does a lot of work in the background.
It’s one of those little things that makes homemade food taste way better. If you’ve ever wondered why restaurant sauces are so smooth and tasty, chances are they started with a roux.
When You Might Need a Flour Substitute
There have been plenty of times I needed to make a roux and realized no flour in the pantry. It happens. But running out of flour isn’t the only reason to look for a substitute. You might also be cooking for someone who’s gluten-free. That was the case for me when my cousin came over for dinner. I had no idea flour wasn’t gluten-free until she told me, and I had to scramble for another option.
Some people also follow low-carb or keto diets, so they try to avoid regular flour. Almond flour or coconut flour works better for them. I didn’t really understand that at first, but once I started paying attention to food labels and ingredients, it made sense. There’s also the times when you’re just experimenting in the kitchen. Maybe you want a nutty flavor, or you’re trying a new recipe that uses something like rice flour or arrowroot instead.
Whatever the reason, knowing what else you can use instead of flour is super helpful. It opens up more ways to cook and lets you adjust recipes based on what you have or who you’re feeding. I’ve learned the hard way that not every substitute works the same, but once you figure out what matches your needs, you’ll be set.
Cornstarch: The Most Common Swap
Cornstarch is the first thing I reach for when I’m out of flour and still need to thicken a sauce. It’s cheap, easy to find, and works fast. The biggest thing to know is that cornstarch doesn’t work the same way as flour in a roux. You don’t cook it in butter. Instead, you mix it with cold water to make something called a slurry. Then you pour that into your hot sauce or soup and stir like crazy.
The first time I tried it, I just dumped the powder straight into the pot. Big mistake. It clumped up fast and looked like jellyfish floating in my soup. But once I learned to make a smooth slurry first, it became a super easy fix. I usually go with about one tablespoon of cornstarch mixed with two tablespoons of water to thicken one cup of liquid.
Cornstarch works best for quick sauces. It gives a nice glossy finish and doesn’t change the flavor. But it doesn’t hold up well if you cook it too long. I’ve had sauces get thin again after simmering too much. So if I’m making something like gravy or a stir-fry sauce, cornstarch is perfect. Just keep an eye on the heat and don’t overcook it.
Arrowroot Powder: Great for Clear Sauces
Arrowroot powder saved my dinner once when I was out of both flour and cornstarch. I found a little bag of it tucked in the back of my baking drawer and thought, “Why not?” I had no clue what I was doing, but it worked better than I expected. It’s actually a really good thickener, especially when you want your sauce to stay clear and shiny.
The cool thing about arrowroot is that it doesn’t make sauces cloudy like flour or cornstarch can. That’s why I like using it for fruit sauces or sweet and sour dishes. It’s also great in anything that’s a little acidic. I once made a lemon glaze with arrowroot, and it turned out smooth and perfect. Cornstarch would’ve gotten weird and gloopy.
Just like with cornstarch, you have to mix arrowroot with cold water first. Never dump it straight into a hot pan, or it’ll clump like crazy. I usually go with about the same amount as cornstarch one tablespoon of arrowroot and two tablespoons of water per cup of liquid. And don’t cook it too long, or it’ll break down and thin out again. Quick and gentle heat is the way to go.
Almond Flour: A Low-Carb Option
Almond flour was a total surprise for me. I didn’t think it could work in a roux, but one time I was making a cheese sauce for a friend who was doing keto, and I gave it a shot. Turns out, with a little butter and patience, it actually works pretty well. It doesn’t thicken the same way as flour, but it gives the sauce a nice body and nutty taste.
When I use almond flour, I start by melting butter in a pan like I would with a regular roux. Then I stir in the almond flour and cook it for a couple of minutes. It doesn’t get that same smooth, pasty texture as flour does, but it blends into the sauce just fine. The trick is to whisk a lot and not let it burn, because almond flour browns quickly.
The flavor is definitely different. It’s a little nuttier, which can be really nice in creamy sauces or cheesy dips. I wouldn’t use it for something like a classic béchamel, but for mac and cheese or a creamy garlic sauce, it totally works. Plus, it’s gluten-free and low-carb, which makes it a good pick if you’re cooking for someone with food restrictions.
Tapioca Flour: Stretchy and Smooth
Tapioca flour was one of those things I bought once for a baking recipe and totally forgot about. But then I needed a thickener in a pinch, and there it was. I used it to make a gravy, and wow it turned out way smoother than I expected. It thickened fast and gave the sauce a kind of silky, stretchy feel that was actually really nice.
The thing with tapioca flour is you don’t need a lot. A little goes a long way. Just like with cornstarch or arrowroot, you have to mix it with cold water first. I learned that the hard way when I added it straight into hot broth and ended up with lumps that wouldn’t go away. Now I always make a quick slurry before adding it in.
One thing I noticed is that if you cook it too long or on too high heat, it can turn kind of gummy. So I use it mostly for quick sauces or things I’m going to serve right away. It’s also great for gluten-free cooking and gives a nice smooth finish. If you want something that thickens fast and looks glossy, tapioca flour is a solid option.
Rice Flour: A Neutral, Gluten-Free Thickener
Rice flour is one of my favorite go-to swaps when I want something that acts close to regular flour. It’s super mild in taste, so it doesn’t mess with the flavor of your sauce, and it’s gluten-free too. The first time I used it was in a creamy mushroom sauce, and honestly, I couldn’t even tell the difference from using wheat flour.
I like to start a rice flour roux the same way I do a regular one melt some butter, then stir in the rice flour. It blends really well and gets smooth if you keep whisking. It doesn’t brown quite the same way, but it still cooks up nicely. I usually let it bubble a bit for a few minutes so it doesn’t taste raw.
Rice flour works great for gravies, white sauces, and soups. I’ve even used it in gumbo when cooking for gluten-free friends. It holds up well to simmering too, which some other substitutes don’t. If you’re looking for something simple and close to the real thing, rice flour is definitely one of the easiest swaps I’ve found.
Coconut Flour: Tasty but Tricky
Coconut flour can be a bit of a wild card. I remember the first time I tried to use it for a roux, I dumped in the same amount as I would with regular flour and the whole thing turned into a thick paste in seconds. That’s when I learned coconut flour soaks up liquid like a sponge. You only need a little, and you’ve got to move fast.
The flavor is also something to think about. It’s got a light coconut taste, which can be really good in the right dish like curries or anything with a tropical or spicy twist. But it can feel out of place in a plain white sauce or classic gravy. I used it in a creamy Thai-inspired dish once, and it turned out great. But when I tried it in a cheese sauce? Not so much.
When I use coconut flour now, I usually mix it into melted butter and stir just enough to blend it smooth. Then I add the liquid slowly and whisk a lot. The sauce thickens up quickly, so I keep a little extra broth or milk nearby in case I need to thin it out. It’s not the easiest substitute, but it can be really tasty if you match it with the right flavors.
Tips for Cooking a Roux with Substitutes
Using something other than flour in a roux takes a little practice, and trust me, I’ve messed up my fair share of sauces figuring it out. One thing I learned fast is to keep the heat low. Some substitutes like almond or coconut flour burn way quicker than regular flour, so I always start with medium-low heat and stay close to the stove.
Whisking is your best friend. No matter which substitute you use, whisking helps keep things smooth and lump-free. I made the mistake of stepping away once while using tapioca flour, and it clumped up like glue. Now I just keep stirring the whole time, even if it feels like my arm’s going to fall off. It’s worth it.
Another tip is to be ready to adjust the liquid. Some flours and starches soak up more than others. Coconut flour, for example, can thicken a sauce fast, and you’ll need to add more milk or broth to get the texture right. Cornstarch and arrowroot work differently they don’t go into a butter base, so I mix them with cold water first before adding them to anything hot.
Mostly, it’s about paying attention and not rushing it. If the sauce looks too thick, add more liquid slowly. If it’s too thin, give it another minute or try a bit more thickener. Over time, you get a feel for how each one behaves. I still mess up now and then, but knowing these little tricks saves me a lot of stress in the kitchen.
When Not to Substitute Flour in a Roux
There are some recipes where nothing really works as well as regular flour. I learned that the hard way when I tried making a classic French velouté sauce with almond flour. It didn’t come out smooth, and the flavor just felt off. That’s when I realized that for certain traditional dishes, flour isn’t just a thickener it’s part of the flavor and texture people expect.
If you’re making something that needs to simmer for a long time, like gumbo or beef stew, cornstarch and arrowroot usually aren’t the best choices. They can break down with heat and time, and your sauce might turn runny or even get stringy. I’ve had that happen with a big pot of gravy I tried to reheat. It looked great at first, then turned into soup after 20 minutes.
Also, if you’re baking a dish that needs a roux as a base like a classic baked mac and cheese some substitutes don’t hold up the same. Coconut flour, for example, can change the flavor too much, and almond flour might not thicken evenly. In those cases, if flour’s an option, I just stick with it.
Sometimes it’s okay to swap, and sometimes it’s worth using the real thing. It depends on the dish and how picky you or your guests are about taste and texture. When in doubt, I think about how the sauce is being used and how long it’s going to cook. That usually helps me decide whether to swap or stay with flour.
Conclusion
Making a roux without flour might sound tricky at first, but once you get the hang of it, it opens up a whole new world in the kitchen. I’ve had to work around missing ingredients more times than I can count, and finding these flour substitutes has honestly made me a better cook. Whether you’re avoiding gluten, cutting carbs, or just ran out of flour mid-recipe, there’s almost always something in the pantry that can save the day.
Cornstarch is my usual go-to for fast sauces, while almond flour and rice flour are great when I want something closer to the original. Arrowroot and tapioca give smooth, glossy results, and coconut flour it’s tricky, but fun in the right dish. Each one has its own quirks, but once you learn how they act on the stove, you can pick the right one for any recipe.
So don’t stress if you’re missing flour. You’ve got options. Try a few, make some mistakes like I did, and soon you’ll know which substitute fits your style. And if you find a combo that works better than flour? That’s the best part. Cooking’s all about learning and tweaking as you go. Give one of these swaps a try next time, and let me know what works best in your kitchen!