Can cornstarch thicken cold liquids? (+3 steps)

In this article, we will answer the question “Can cornstarch thicken cold liquids?”, and what is the thickening mechanism of cornstarch along with its alternatives.

Can cornstarch thicken cold liquids?

No, cornstarch cannot thicken cold liquids. Cornstarch thickens liquids by gelatinization. The temperature range for this process to occur is 62-72°C for cornstarch. Above and below this temperature,  the starch will be suspended in the liquid. When left untouched, it will settle down or form lumps in the liquid.

Read on if you want to know how to use cornstarch to perfectly thicken your sauces, curries, and custards. Do not worry if you run out of cornstarch, follow the guide below to find out what you can use instead.

All you need to know about starch

Starch is a polysaccharide with a large molecular weight. The two polymer chains present in starch are amylose and amylopectin. The structure of starch varies with its source. It is odorless, tasteless, and appears white.

Plants store their energy in the form of starch. It is broken down into simple sugars to obtain energy. Foods like corn, potato, rice, cassava, and wheat contain starch in significant amounts. In the alcohol industry, starch is subjected to fermentation to produce ethanol. 

How does starch thicken liquids?

There are two stages involved in the thickening action of any starch.


It is basically the irreversible disarrangement of the crystalline structure of starch. In the presence of heat and water, amylopectin loses its crystalline structure and allows the water to enter into the amorphous regions of the starch granule.

This results in swelling of the molecule. Eventually, the whole granule disintegrates completely. The temperature at which this process takes place varies for each type of starch.


Starch is heated to a few more degrees than its gelatinization temperature to get the maximum thickness. This allows each granule of starch to swell up on its own. It is important to keep agitating the mixture lightly to avoid forming lumps. However, agitating too vigorously can also break the starch mesh. Heres, how you can tell when to stop stirring and heating:

  1. The slurry does not taste like raw starch.
  2. The liquid is sticking to the back of the spoon.
  3. The desired consistency is achieved without any lumps.

What is cornstarch?

Corn starch or cornflour is ground from the corn kernel. Maize kernel is 72-72% starch by weight and it is present in the grain endosperm. Cornstarch is used as a thickening agent in food. It is used to thicken gravies, curries, soups, and custards.

As a result of cornstarch gelation, the liquid develops a translucent appearance rather than an opaque one, which is the case for most thickeners. Therefore, cornstarch is preferred for culinary uses.

It is also used as an anti-caking agent in powdered sugar or baking powder. In the paper industry, it is used as an anti-sticking agent. This versatile product also finds its uses in the textile industry.

How to use cornstarch to thicken liquids?

  1. Add 1tbsp cornstarch in water for each cup of liquid. Mix until smooth.
  2. Add this paste or slurry into the simmering hot liquid and stir continuously and gently.
  3. Turn off the flame when smooth and of desired consistency.

What are the substitutes for cornstarch?

Wheat flour

It is used to make a roux which is typically used to thicken bechamel sauce, gumbo, and some soups and curries. roux has a rich taste because butter is added to coat the flour. Roux is cooked to a brown, golden, or white color depending on its end-use.


Arrowroot powder is ground from the tuber of Maranata arundinacea. It is gluten-free and does not make the liquid opaque while thickening.

Tapioca starch

Tapioca flour is ground from cassava. It tastes sweet but not enough to overpower the flavor of other ingredients. It adapts suitably to freezing and reheating because it does not form clumps. It is gluten-free and retains its color despite cooking.

Xanthum gum

It is produced as a result of fermentation by Xanthomonas campestris in the form of a gel which is later dried to make powder. Xanthum gum has excellent thickening, stabilizing, and emulsifying properties. This gluten-free substitute is widely used to thicken and stabilize gravies, curries, dressings, soups, and ice cream for a rich creamy texture

It imitates the gluten rheological characteristics and is used in gluten-free baking. A small amount of xanthum gum works just fine at a wide range of temperatures. 

Other FAQs about Cornstarch that you may be interested in.

Does cornstarch go bad?

Can you substitute cornstarch for baking soda?

Can cornstarch thicken cold liquids?


In this article, we answered the question “Can cornstarch thicken cold liquids?”, and what is the thickening mechanism of cornstarch along with its alternatives.


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