How To Thicken A Slow Cooker Stew (Several Ways)

Many people get the problem of their slow cooker stew being too thin and watery. If you set your cooker to make a stew while you are out at work, it’s disappointing to come home and find that your stew isn’t thick enough.

Luckily, there are several ways to quickly thicken a slow cooker stew.

Thicken a slow cooker stew by adding a starch slurry such as flour, cornstarch, potato starch, or chickpea flour to the stew in the final thirty minutes. Blending a portion of the stew and adding it back in will also thicken it.

Stew cooked in the slow cooker can become a little watery and thin because the sealed lid doesn’t allow for evaporation. To get your stew to be satisfyingly thick and delicious, here are the best approaches you can take, depending on time and your desired flavor and thickness.

Best Way To Thicken A Slow Cooker Stew

The fastest and easiest way to thicken a stew or sauce in a slow cooker is to use a thickening agent like starch. Usually, you only need to add a tablespoon or two of starch like cornstarch or flour mixed with water.

Most starches are mixed with liquid before adding them to your stew to form a paste or slurry. This prevents the starch from clumping into dry blobs rather than distributing throughout the sauce to thicken.

Some of the cheapest methods of thickening stews might be in your pantry and are relatively inexpensive.


If you’ve ever made a roux or white sauce, you know that flour is the main ingredient for thickening the milk. Mixing flour with a fat such as melted butter will make a smooth paste that you can stir into your stew towards the end of the cooking time.

While a roux calls for equal parts flour and fat, you can use hot water or broth instead of melted butter if you prefer. You want to ensure the flour is worked into a smooth paste with no dry, powdery lumps.

Spoon a little of the broth from the top of the stew into a bowl and mix your slurry. This ensures the taste isn’t diluted and avoids adding more liquid to the stew.

You need to ensure that your flour cooks into the stew, as this is how it thickens the watery liquid. Stir in your slurry of flour and water or flour and melted butter, and stir well. The raw flour will take around thirty minutes to cook through the stew and successfully thicken it.

Expect to use 1 small cup of hot broth or water to 1-4 tablespoons of flour, depending on the size of your stew.

Whisk the broth and hot liquid well so that it is fully combined, and there are no lumps before adding it to your pot. Stir your stew until the liquid begins to thicken.

Keep in mind adding flour creates a cloudy sauce, while cornstarch will keep it clear and glossy – both good for different occasions.


If you need to keep your meal gluten-free, you can use several alternative starches to make a thickening slurry. Cornstarch is one of the most popular. As with flour, you’ll use 1-4 tablespoons, depending on the size of your meal.

Use cornstarch similar to regular flour. Put some cornstarch in a separate bowl and add approximately a cup of cold liquid to make a smooth paste. Cornstarch needs cold water or it thickens before you add it to the stew.

Whisk well, and pour the mixture slowly into your stew. Stir your slow cooker stew so the slurry can mix through your hot stew and thicken the sauce.

Avoid using cornstarch in acidic dishes such as those with vinegar, fruits, tomatoes, and juice.

Potato Starch

Another gluten-free option for thickening your stew is to use potato flour. Some people don’t like the taste of cornstarch or flour in their stews; these often work best for creamier sauces.

Potato starch works better in acidic dishes like stews with a tomato base. It also works well in warm dishes and is best added to stews that are not piping hot. A high temperature can make the potato starch clump rather than thicken.

Potato starch does not need a long cook time and is best added at the end. As with other starches, add a little liquid to make a slurry. In the case of potato starch, use warm water or stock rather than hot.

If you are substituting potato starch for cornstarch, use two teaspoons of potato starch for every tablespoon of cornstarch.

Gram Flour

Chickpea or gram flour is made from garbanzo beans and produces an excellent thickening protein. Some people find the taste a little strong, but I find chickpea flour’s earthy, buttery, rich flavor a perfect addition to slow cooker curries and legume stews.

While it works best in potato-based stews, I’ve found that roasting the flour first removes the raw flavor and makes it even better.

The added bonus of chickpea flour is that it is higher in protein than some of the alternative thickeners. Use some water to make a paste with your chickpea flour, and add it to your slow cooker, stirring well.

Other Ways To Thicken Stew If You Don’t Have Flour

If you do not have any starches such as wheat flour, cornstarch, chickpea flour, or potato flour to hand, there are other ways to thicken up your slow cooker stew.

Blend A Portion Of The Stew

You can try blending your stew with a stick blender, as pureeing some vegetables, such as potatoes and carrots, will thicken the liquid.

Only blend a little, as you still want your stew to have bite-sized chunks to avoid becoming a creamed soup. One really good way is to ladle out some of the stew, blend it separately, then return it to the slow cooker.

This thickens the overall stew but retains most of the solid ingredients.

Add Instant Mash

Adding instant mashed potatoes works well if you make a vegetable or legume stew with a potato base. Not only does the instant mash thicken the stew, but by adding what is essentially dehydrated potatoes, you add extra nutrients to your meal.

Add the mash flakes a little at a time, stirring, until the instant mash is cooked in and the stew has reached the desired consistency.

Key Questions On Thickening Slow Cooker Stews

When Should You Thicken Slow Cooker Stew

If you need to add thickeners like cornstarch, add it towards the end, and give the stew around 20-30 minutes to fully thicken.

Don’t add thickeners at the start of the cooking process as vegetables and meat will release liquid while they cook.

Will A Stew Thicken By Itself In The Slow Cooker?

As food like potatoes, beans, and root vegetables slowly break down as they cook in the slow cooker, they can naturally thicken your stew. But at the same time, ingredients release water and fat into the liquid.

It’s unlikely the stew will thicken by itself in the slow cooker as the liquid can’t evaporate. You will need to thicken it by adding a starch or blending some of it.

Can You Take The Lid Off Slow Cooker To Thicken?

Opening the slow cooker’s lid near the end of the cooking time can help thicken your stew a small amount. Some of the trapped moisture will evaporate but you will never get the rolling boil of a saucepan as the temperature drops with the lid off.

An easy method is to use something wooden, like a chopstick or skewer, to prop open the lid a little. Avoid using a metal implement to prop the lid, as it can get hot and cause an accidental burn.


Adding some flour, potato starch, corn starch, or chickpea flour can help you thicken your slow cooker stews. Some starches must first be made into a slurry with some liquid, while others, like chickpea flour, can be stirred directly into the stew.

This process will take about thirty minutes to fully cook the starch and thicken the stew. If pressed for time, blend the stew or add instant mashed potato.

Cat Hellisen

Cat is a writer with a wealth of experience in food, cooking and fitness. They have written several books and love long walks on the beach with their dog. About Cat.

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