How to thicken keto and low carb gravies, sauces, and soups

Traditionally, many choose to thicken sauces and soups with high-carb ingredients like flour or cornstarch. If you’re eating very low carb, keto, or gluten-free, those are not good options. But don’t worry! We have a few pro tips to help you thicken up sauces, gravies, soups, and more — without adding excess carbs.

Keto and low carb thickeners:

  • There are a wide variety of ways to thicken foods without using traditional high-carb options. Instead, you can use alternative ingredients, which we’ll describe below.
  • As an added plus, there are also some simple cooking techniques that yield a creamier consistency without adding carbs or dairy. We’ll also explain these.
  • Lastly, in this guide, we’ll walk you through which keto and low carb foods naturally thicken recipes and can add a bit of flavor, protein, and fat while keeping carbs low.

Top 5 keto thickener substitutes

Most low carb or keto thickeners are made from vegetable gums or fiber and often have very few — if any — carbs. Some thickeners work best in cold applications while others work well for baking or cooking.

Here are a few that we’ve used in our Diet Doctor test kitchens.

1. Xanthan gum

Used for baking or thickening soups or sauces, xanthan gum has zero net carbs. Use in small amounts and be sure to sprinkle the thickener into soups or sauces a little at a time so that it doesn’t clump.

Also, too much xanthan gum can yield a gummy or slimy texture, so it’s best to use minimal amounts. Begin with ¼ teaspoon at a time and add until you reach the desired consistency.

2. Guar gum

A plant fiber from the seed of the guar plant, guar gum has zero net carbs. It is used in commercial baking and ice cream to improve texture and consistency. It also extends the shelf life of baked goods.

You should add guar gum to recipes in small amounts since it is said to have eight times more thickening power than cornstarch. Popular uses for guar gum include baking and cold applications like dessert fillings and salad dressings.

3. Glucomannan (konjac):

From the konjac plant root, glucomannan is a soluble plant fiber that also has zero net carbs. It’s used to make keto or low carb noodle replacements that are sold commercially.

One of the strongest thickening agents, glucomannan works best when mixed with a bit of cold water, adding it in once your soup, stew, or gravy is finished cooking. Be sure to use it extremely sparingly — especially since it continues to thicken recipes as they cool.

Glucomannan can also be used in baked goods to make them a bit softer and flexible.

4. Agar agar

A plant-based substitute for gelatin, agar agar is derived from seaweed. It is most frequently used in cold applications like desserts, gelatins, puddings, or sauces, but can be used to thicken soups or sauces if added toward the end of cooking time and is allowed to cool.

Like gelatin, agar agar must first be dissolved in water and will thicken gradually. It can be purchased as flakes or powder and contains about 0.5 grams of net carbs per tablespoon.

5. Gelatin

Gelatin is an animal-based thickener. Like agar agar, gelatin can be used as a thickening agent in desserts or sauces. It, too, is most frequently dissolved in water and is then added to recipes. It also takes some time to begin to thicken or set in recipes.

Gelatin helps no-bake cheesecakes or pies to set up firm enough to slice. Gelatin isn’t ideal for baking but can be used in bars and cookies to add a chewy texture.

Cooking techniques to thicken keto or low carb recipes

Sometimes thickening a keto soup, sauce, or gravy is as simple as pureeing or using a low simmer, and a lot of patience to let a mixture of ingredients thicken.


When pureeing, place some or all of the ingredients in a blender, food processor, or immersion blender to create a smooth texture. Our recipe for salsa verde is a perfect example on how to make a creamy sauce, using an immersion blender — in just five minutes!

If you want varying textures, then you can add meat or other ingredients after pureeing the vegetable components. A great example of when this method are used, is in our recipe for creamy low carb chicken, kale and cauliflower soup. If you are using thicker ingredients, only puree 1/3 to 1/2 of the amount at a time, leaving the remaining ingredients intact.

Remember to always use caution when pureeing hot soups and other warm ingredients. In a blender or food processor, hot foods can build up pressure and cause the contents to splash or “explode” in every imaginable direction. Decrease the risk of getting burned or creating a mess by not filling the blender or food processor all the way to the top. A handheld immersion blender also works well.

Our buttery and warm roasted cauliflower mash is an example of when to use caution to avoid burns.


Letting food thicken by slowly cooking on low heat takes a bit more time and patience, but don’t let that stop you. Simmering also concentrates the flavors and gives you an even more rich and robust sauce.

We use simmering as a cooking method in our recipe for keto hamburger patties with tomato sauce and cabbage. The sauce is a mixture of cream, tomato paste, and seasonings, and as the sauce simmers, the cream naturally thickens and adds a fantastic flavor and silky texture to the hamburger patties.

Another winning benefit with simmering is that while cooking, you’ll get a delicious smell throughout the kitchen. With our delicious low carb spinach and artichoke soup and South American garden chicken with cauliflower rice, you’ll warm up both your house and tummie.

Keto and low carb ingredients that naturally thicken gravies, sauces, and other recipes

Sometimes, thickening foods is as simple as adding or adjusting a few low carb or keto ingredients:

  • cream cheese
  • cheese
  • heavy cream
  • sour cream
  • crème fraîche

  • egg yolks
  • egg whites
  • coconut cream
  • avocado
  • nuts

Dairy-based thickeners

Many dairy products commonly used in keto recipes can also help to thicken. Cheese, heavy cream, cream cheese, or sour cream all add fat, protein, and create a thicker, richer, creamier taste.

Cream cheese

Crème fraîche

Dairy-free keto or low carb thickeners

When it comes to dairy-free thickeners, there may be more options than you think:

Coconut cream