8 Best Low Carb and Keto-friendly Thickeners To Use Instead Of Cornstarch

In the world of food, there are a lot of vegetable and meat dishes that all taste better with a delightfully creamy sauce or soup. What makes these sauces and soups even better is a beautiful thick texture. 

8 Best Low Carb and Keto-friendly Thickeners To Use Instead Of Cornstarch

To make our sauces and soups thicker, most of us turn to thickeners like cornstarch, as they act quickly to change a food’s consistency.

However, adding cornstarch isn’t an option for those of us sticking to a low-carb or keto diet that only gives us 20 g of carbs a day.

As you probably already know, flour and cornstarch are high in carbs and therefore not suitable for keto. Here are the best things you can use instead to get that super thick consistency still, but without having to break your low-carb diet. 

We’ll show you what each substitute offers, when to use it, and where you can buy it. Keep reading if you want to learn more!

Why Is Cornstarch Bad For Low-Carb, Keto Diets?

The reason cornstarch is bad for low-carb, keto diets is simply down to the fact it contains an incredibly high amount of carbohydrates. For context, individuals following a low-carb, keto diet may only be allowed to eat 20 grams or fewer carbs per day. 

In just 100 g of cornstarch, there are approximately 90 grams of carbs and 381 calories. By simply thickening one sauce or soup, someone could use more than 4 times their daily limit of carbs. 

With that in mind, it is important to find suitable alternatives to still enjoy your food without ruining all your hard work.

Now you know this, we can start to look at the top 8 low-carb, keto-friendly thickeners to use instead of cornstarch. We urge you to read our list thoroughly if you want to stick to your diet easily. 

Glucomannan Powder

The first thickener substitute for cornstarch on our list is glucomannan powder. Glucomannan powder is produced using the Konjac plant’s root.

The powder is most commonly used in tablet form to reduce appetite, but it can also be easily used in cooking as an alternative to cornstarch. 

Gluten-free, this low-carb, keto-friendly substitute is made from a soluble fiber that quickly absorbs liquid. This not only helps to thicken soups and sauces but also creates a feeling of fullness which comes in handy when trying to control your diet. 

When It Works Best?

The glucomannan powder substitute will work wonders for you when you have a chicken broth that needs thickening. The powder won’t take anything away from your food, but it will thicken it up nicely. 

Before using the powder to thicken your food, you should first whisk it with cold water. Only then can it be poured into your broth. If not whisked, the powder will make your broth lumpy and heavy to eat. 

1 teaspoon of the powder is enough to thicken 1 cup of broth. Feel free to experiment though to find your desired consistency.

Where To Find It?

You can buy glucomannan powder on Amazon.com. Here, you’ll find it sold at a very reasonable price. It can also be purchased at Walmart.com

Xanthan Gum

Xanthan gum is the most commonly used keto-friendly thickener when it comes to replacing cornstarch or flour. It can be used in a wide range of low-carb, keto recipes including smoothies, soups, and sauces.

It does a fantastic job at improving flavors, appearance, and of course texture.

Readily available, this substitute is a type of additive that binds, stabilizes, thickens, and emulsifies any liquid you add it to. This is because, like glucomannan powder, it is produced from a soluble fiber that easily absorbs water.

Xanthan gum is primarily sold in powder form.

When It Works Best?

Xanthan gum works best in a range of circumstances, but the very best has to be when making a bechamel sauce or thick gravy. To thicken your sauce to perfection, use ½ teaspoon of the gum for every 3 cups of sauce you’re making. 

Where To Find It?

You will find Xanthan gum in most grocery stores. You can also buy it on Amazon.com.

Guar Gum 

Another type of gum that acts as a brilliant substitute for cornstarch is guar gum. Also referred to as guaran, this gum is extracted from a type of bean called guar bean.

Used to stabilize and thicken food, this gum is a soluble fiber too. This means guar gum is also fantastic at absorbing liquid and changing its viscosity.

Another added advantage of guar gum is that it is super low-calorie as well as low-carb and keto-friendly.

When It Works Best?

Usually, guar gum is the best low-carb thickener to use when thickening dairy products. It works best when thickening yogurt, kefir, cottage cheese, and ice cream.

However, a lot of people still like to use the gum to thicken their sauces too. Either way, the guar gum is sure to thicken your food almost instantly.

In fact, when compared to flour, guar gum performs a lot better, absorbing a lot more water. Bearing this in mind, you probably only need one-sixteenth of what the recipe calls for. 

For example, if your recipe asks for ¼ cup of flour, you’ll only need to use ¾ teaspoon of gum.

Where To Find It?

You will find a range of guar gum products on Amazon.com.

Chia Seeds 

Next up we have chia seeds. For those that didn’t know, chia seeds are actually the seeds of the Salvia columbariae and Salvia hispanica plants. These plants help make up the mint family. One is found in Mexico and the other in Central America. 

The seeds tend to be black, gray, brown, or white in color and small in size. They have the unique ability to be hydrophilic.

It is this hydrophilic ability that makes the chia seeds such effective thickeners. When soaked in water, the seeds can absorb up to 12 times their original weight in liquid.

The seeds develop a gel-like texture that is low in carbs and rich in omega fatty acids.

When It Works Best?

Unlike other thickeners on the list, chia seeds aren’t used that often. Instead, they are best used when making smoothies and chia pudding.

They can take longer to work so give the seeds two or three hours if you want the best results.

Where To Find It?

Chia seeds are widely available with them being sold in most grocery stores. These include Kroger, Aldi, Safeway, and Target. You will also find them on Amazon.com.

Coconut Flour

The next cornstarch thickening substitute we have for you is coconut flour. Produced by drying and grounding the coconut meat, this thickener has a sweeter taste than the other thickeners on our list so far. 

8 Best Low Carb and Keto-friendly Thickeners To Use Instead Of Cornstarch (1)

It also contains a lot more fiber and a higher fat content than most flours. However, luckily for us, coconut flour also contains fewer carbs, which is perfect for low-carb, keto diets. 

The most popular brands of coconut flour contain carbs that are a type of soluble fiber. This helps the flour quickly absorb water, in turn, thickening any liquid it touches.

When It Works Best?

If you want to make the most of coconut flour, you should use it when thickening soups, sauces, and stews. 

For the best results, the coconut flour first needs to be whisked with cold water. One part should be enough. This should turn the flour into a slurry.

It is this slurry that can then be added to your liquid. All you need to do then is mix the two together until you reach your desired consistency.

Where To Find It?

The best place to find coconut flour is on Amazon.com.

Flax Seeds

Coming from a plant called Linum usitatissimum, flax seeds are only small in size and come in different shades of brown and yellow. Interestingly, the flaxseed plant isn’t just used in the food industry. The plant is also commonly used in the textile industry too.

Like the chia seeds, flax seeds love absorbing water to form a mucilaginous coat. This coat gives the seeds the ability they need to turn water and other liquids into gel-like substances.

It is worth noting that flax seeds have outer shells that need to be ground down first when using the seeds as a thickener. The outer shells disrupt the absorption of liquid which is no good.

When It Works Best?

Flax seeds are the perfect choice when it comes to baking. They work best when developing the texture of a wide range of baked goods without increasing the number of carbs. This ensures your food stays keto-friendly.

Where To Find It?

You’ll find flax seeds in most local grocery stores. Alternatively, you can buy them on Amazon.com.

Psyllium Husk

A plant-based product, psyllium husk is extremely popular with people following a low-carb, keto-friendly diet. Offering impressive thickening abilities and not too many carbs, psyllium husk also has no calories which is always nice. 

Made from the Plantago ovata plant, this thickener is made 100% from soluble fibers. That is why it contains no net carbs. 

Similar to most of the thickening substitutes on our list so far, this cornstarch substitute works by absorbing any liquids you add it to.

When added to a liquid, the husk will produce a gel-like consistency that perfectly thickens your food. The fact it is also tasteless helps make it a top keto thickener choice.

When It Works Best?

The psyllium husk works perfectly in any type of keto baking. The reason for this is simple. Psyllium husk creates the textures non-keto baked goods have. This lets you enjoy your favorite baked goods while sticking to your diet.

Where To Find It?

Psyllium husk is typically found around the health section or gluten-free section in most grocery stores. If you can’t find it in your local store, head to Amazon.com.


The final keto-friendly thickener on our list is agar-agar. Most commonly used in Asian cuisine, this Red Seaweed algae by-product has made its way into American kitchens.

Despite being made from two different types of carbohydrates (agaropectin and agarose), agar-agar is still very low in carbs.

Agar-agar that we use in food is available in two forms. Those forms are powder and flakes. Agar-agar makes such a good thickener not just because of its performance, but also because it has no taste. This means it won’t affect the overall flavors of your food. 

Much stronger than gelatin, 5 times to be exact, agar-agar works fantastically in keto-cooking so be sure to check it out.

When It Works Best?

Thanks to its super-strong characteristics, agar-agar works best in yogurts and puddings or any other food that needs a gelatinous texture and consistency.

When using agar-agar, it needs to be simmered in the liquid in order for it to dissolve. This should only take a couple of minutes. When you then let the agar-agar cool down it will produce a gelatinous consistency.

Where To Find It?

The best place to find agar-agar is on Amazon.com or in an Asian market. Having said that, there are local grocery stores that stock it too.

Final Thoughts 

Following your low-carb, keto-friendly diet can be tough at times, but it doesn’t mean you have to completely cut out the things you enjoy most. Thanks to a wide range of awesome alternatives and substitutes, you can alter your favorite foods to fit your diet. 

In this article, we have shown you 8 different low-carb thickeners you can use to thicken your food without using cornstarch or flour, both of which have a high content of carbohydrates.

From our list, you should be able to see that there is a wide range of excellent options you can use to thicken some of your favorite foods without breaking your diet.

Whether you want to enjoy a refreshing ice cream or make the best bechamel sauce you’ve ever made, one of the thickeners on our list can help.

While the thickeners on our list vary in terms of how they work, they are all guaranteed to give you quick, easy results and a much lower content of carbs.

All you need to do now is take a closer look at our list and decide which thickener works best for you. There’s nothing wrong with trying a few to see which one suits you best!

Anna Kadance