Difference Between All Purpose Flour And Cornstarch

In the world of cooking and baking, the choice between all-purpose flour and cornstarch can significantly influence the texture and structure of your culinary creations.

Understanding the differences between these two common ingredients is not just a matter of culinary curiosity—it’s essential for mastering recipes from crispy fried foods to velvety sauces and delicate pastries.

Why does this matter? Because every meal is an opportunity to create memories and experiences, and knowing how to use these powders can elevate your cooking from good to great.

What Exactly Are All-Purpose Flour and Cornstarch?

All-Purpose Flour:

Often simply called “flour,” this kitchen staple is made by grinding wheat, retaining a portion of the protein (gluten) which provides elasticity and strength in baking. It’s versatile, hence the name, and is used in a wide range of recipes, from bread to cookies.


Derived from the endosperm of corn kernels, cornstarch is a fine, white powder primarily used as a thickening agent. It’s gluten-free and has twice the thickening power of flour, making it a preferred choice for glossy, clear sauces and soups.

Composition and Properties of All-Purpose Flour and Cornstarch

Understanding the composition and properties of all-purpose flour and cornstarch can enhance your culinary knowledge and skills, helping you make informed decisions about which to use in your recipes. Here’s a detailed look at their main ingredients, nutritional components, textures, and key chemical properties.

Main Ingredients and Nutritional Components

All-Purpose Flour:

  • Main Ingredients: Milled from hard wheat or a blend of hard and soft wheat, all-purpose flour typically contains a moderate amount of gluten, suitable for a wide range of baking needs.
  • Nutritional Components: All-purpose flour is a significant source of carbohydrates and provides a moderate amount of protein, primarily gluten. It also contains small amounts of vitamins, such as B vitamins, and minerals like iron, especially if fortified.


  • Main Ingredients: Cornstarch is derived solely from the endosperm of corn kernels, making it concentrated starch.
  • Nutritional Components: Cornstarch is almost entirely carbohydrate, specifically starch, with minimal protein or fat. It lacks the vitamins and minerals found in all-purpose flour, offering primarily energy in the form of calories.


All-Purpose Flour:

  • The texture of all-purpose flour is somewhat gritty when dry and becomes sticky and elastic when mixed with water due to its gluten content. This property allows it to form doughs and batters that can hold their shape under heat.


  • Cornstarch is powdery and very fine to the touch. When mixed with liquid and heated, it becomes slick and gelatinous. This makes it excellent for creating smooth, flowing textures in sauces and fillings.

Key Chemical Properties

All-Purpose Flour:

Gluten Content: Gluten, which is a protein complex formed from gliadin and glutenin, provides elasticity and strength. When flour is mixed with water, gluten strands swell to form a network that can trap air and carbon dioxide during baking.

Gelatinization Temperature: Flour begins to gelatinize around 140°F (60°C), at which point the starch granules absorb water and swell, thickening the mixture.


Absence of Gluten: Cornstarch contains no gluten, making it suitable for gluten-free cooking and baking.

Higher Gelatinization Temperature: Cornstarch starts to thicken at a slightly higher temperature than flour, around 144 to 158°F (62 to 70°C), and requires less time and energy to thicken effectively.

Translucency When Cooked: Unlike flour, cornstarch thickened sauces are clear and glossy, which is preferable for dishes where visual appeal is important.

Common Uses of All-Purpose Flour and Cornstarch in Cooking and Baking

Both all-purpose flour and cornstarch are staples in kitchens around the world, each serving specific roles in cooking and baking based on their unique properties.

Common Uses of All-Purpose Flour

Baking: All-purpose flour is the go-to flour for baking bread, cakes, muffins, and other pastries. Its gluten content helps dough and batters rise and maintain structure.

Thickening Agent: It’s commonly used to thicken sauces, gravies, and soups. When cooked, flour-based roux or slurry adds not only thickness but also a slight cloudiness and a robust flavor.

Coating: Flour is often used to coat foods before frying. It helps to create a crispy exterior and prevents the inside from drying out during cooking.

Binding: In recipes for meatballs or veggie burgers, flour can act as a binder to help the ingredients hold together.

Pasta Making: Many homemade pasta recipes call for all-purpose flour due to its gluten content, which gives the pasta dough elasticity and firmness.

Common Uses of Cornstarch

Thickening Agent: Cornstarch is a preferred thickener for pies, sauces, puddings, and Asian dishes because it gives a clear, shiny appearance and smooth texture. It thickens at a lower temperature and can be mixed with cold water to make a slurry.

Baking: While not a primary baking ingredient, cornstarch is often used in conjunction with flour to soften the texture of cakes and cookies. It’s also a key ingredient in shortbread recipes.

Frying: Used either alone or mixed with flour, cornstarch creates a crisper, less greasy crust for fried foods.

Anti-Caking: Its fine, powdery texture prevents ingredients from clumping together. It’s often used in powdered sugar or spice mixes to maintain a free-flowing consistency.

Can All-Purpose Flour Be Used as a Thickening Agent?

Yes, all-purpose flour is frequently used as a thickening agent. To use flour for thickening, it’s typically combined with fat (like butter) to make a roux, which is cooked before adding the liquid you want to thicken. This cooking process is essential to eliminate the raw flour taste. Flour can also be made into a slurry by being whisked into cold water before adding it to hot liquids, but it requires longer cooking to properly thicken and clear the raw taste.

Can Cornstarch Be Used in Baking?

Yes, cornstarch can be used in baking, often to achieve a desired texture. When added to cake, cookie, or shortbread recipes, cornstarch helps to create a tender and fine crumb. It’s also used to make cornbread and other baked goods where its fine texture and binding capabilities are beneficial. Cornstarch mixed with flour can mimic cake flour, which is lower in protein and gives a lighter texture to cakes.

Substituting All-Purpose Flour and Cornstarch

Substituting all-purpose flour for cornstarch or vice versa depends on the specific cooking or baking context, as their properties affect recipes differently. Here’s how you can substitute these ingredients along with alternatives for each.

Substituting All-Purpose Flour for Cornstarch

All-purpose flour can substitute for cornstarch, but it’s not a 1:1 swap because flour doesn’t have as much thickening power as cornstarch.


Use about 2 tablespoons of flour for every 1 tablespoon of cornstarch.


For thickening, flour works best when made into a roux (cooked with fat) before adding liquids, as this reduces the likelihood of a raw flour taste and creates a smoother consistency. It’s important to cook your sauce or gravy for a few minutes longer to ensure the flour is fully cooked.

Substituting Cornstarch for All-Purpose Flour

Cornstarch can also replace flour as a thickening agent, but again, it requires adjustment.


Use about 1 tablespoon of cornstarch for every 2 tablespoons of flour.


Mix cornstarch with a little cold water to form a slurry before adding it to your hot liquid, which prevents clumping. This is especially effective in sauces, gravies, and pie fillings where clarity and smoothness are desired. Keep in mind that sauces thickened with cornstarch should not be boiled too vigorously after adding cornstarch as it can break down and lose its thickening power.

Best Alternatives to All-Purpose Flour and Cornstarch

For those looking to replace all-purpose flour or cornstarch due to dietary restrictions or availability issues, there are several good alternatives:

Rice Flour:

A fine gluten-free flour that can replace both all-purpose flour and cornstarch. It is especially good for frying and baking.

Arrowroot Powder:

A starch similar to cornstarch with a neutral flavor and good thickening properties. It works well in acidic dishes and freezes well, unlike cornstarch.

Tapioca Starch:

Derived from cassava, it’s a good alternative for cornstarch for thickening, baking, and an excellent choice for dishes requiring a glossy appearance.

Potato Starch:

Similar to cornstarch, it’s excellent for thickening and is preferred in baking recipes for adding moisture to baked goods.

Almond Flour or Coconut Flour:

While these cannot generally replace cornstarch due to their different properties and higher fat content, they are excellent gluten-free alternatives to all-purpose flour for baking with adjustments to liquid ratios in recipes.

Practical Tips for Storing All-Purpose Flour and Cornstarch & Avoiding Common Mistakes

Storing your ingredients properly and using them correctly can significantly affect the quality and outcome of your dishes. Here’s how to handle all-purpose flour and cornstarch for optimal results, along with tips on avoiding common pitfalls.

How to Store All-Purpose Flour

Keep it Cool and Dry: Store flour in a cool, dry place away from direct sunlight. Heat and moisture can cause flour to spoil or develop a musty odor.

Airtight Container: Use an airtight container to prevent the flour from absorbing odors and moisture from the environment. This also helps keep out pests.

Label and Date: Mark the container with the purchase date so you can keep track of its age. All-purpose flour can typically be stored for up to a year under ideal conditions.

How to Store Cornstarch

Dry Environment: Like flour, cornstarch should be kept in a cool, dry place. Moisture is particularly detrimental to cornstarch as it can lead to clumping and bacterial growth.

Original Packaging Inside an Airtight Container: Cornstarch can remain in its original packaging, but placing the package in an airtight container can provide extra protection against moisture and odors.

Avoid Exposure to Odors: Cornstarch is also susceptible to absorbing strong smells, so keep it away from spices and other strong-scented ingredients.

Common Mistakes to Avoid with All-Purpose Flour

Not Sifting Flour: Especially important for baking, sifting flour helps to aerate it, leading to lighter cakes and pastries. It also helps to remove any lumps that could affect the texture of your baked goods.

Measuring Incorrectly: Using a measuring cup to scoop flour directly from the bag can compact it, leading to up to 30% more flour than needed. Instead, fluff the flour with a spoon, scoop it into the measuring cup, and level it off.

Overmixing: When preparing doughs and batters, overmixing can lead to the development of too much gluten, resulting in tough, chewy baked goods. Mix just until ingredients are combined.

Common Mistakes to Avoid with Cornstarch

Adding Directly to Hot Liquids: Cornstarch should first be mixed with a cold liquid to form a slurry before adding to a hot mixture. This prevents clumping and ensures smooth incorporation.

Overcooking: Cooking cornstarch-thickened sauces for too long or at too high a temperature can break down the starch molecules, causing the sauce to thin out again.

Freezing: Avoid using cornstarch in dishes you plan to freeze, as it can cause the texture to become spongy when thawed. Use alternatives like arrowroot or tapioca starch for better freeze-thaw stability.

Comparative Analysis of All-Purpose Flour vs. Cornstarch

Understanding how all-purpose flour and cornstarch affect cooking and baking outcomes is crucial for choosing the right ingredient for the right application. Here’s a breakdown of their effects in different culinary uses, along with a comparative analysis of their performance in thickening and baking.

Differences in Cooking and Baking Results

Texture: All-purpose flour tends to create a denser, more elastic texture due to its gluten content, ideal for breads and cakes that need structure. Cornstarch, being pure starch, provides a lighter, more delicate texture and is often used in more refined and silky desserts like puddings or custards.

Appearance: Sauces thickened with cornstarch are clearer and glossier, whereas those thickened with flour are more opaque and have a slightly matte finish.

Flavor Release: Cornstarch has a neutral flavor, making it suitable for dishes where you don’t want the thickener to alter the flavor profile. Flour can impart a slightly earthy, starchy taste unless properly cooked out.

Which is Better for Thickening Sauces?

Cornstarch is generally better for thickening sauces if you desire a translucent appearance and a smooth texture. It thickens at a lower temperature and requires less quantity to thicken than flour.

All-purpose flour is a good choice for hearty dishes like stews or gravies where the slight cloudiness and robust flavor can complement the dish well. It’s also beneficial where the sauce is meant to cook for a longer period, which can fully cook out the raw flour taste.

Which is Better for Baking?

All-purpose flour is the staple for baking due to its gluten content, which is necessary for the structure and rise in baked goods like bread, cakes, and pastries.

Cornstarch is not typically used alone in baking but can be mixed with flour to soften cakes’ texture, reduce gluten formation, and make baked goods tender.

Practical Applications

Effect on Texture of Baked Goods
  • Using all-purpose flour leads to chewier and more structured textures, ideal for breads and rolls.
  • Mixing cornstarch with flour in cakes and cookies can create a tender and fine crumb by inhibiting gluten formation.
Recipes Specifically Calling for All-Purpose Flour
  • Bread: All-purpose flour provides the necessary gluten for the bread to rise and hold its shape.
  • Cookies: Helps create structure and chewiness, especially in recipes like chocolate chip or oatmeal cookies.
  • Roux for Gravies and Sauces: Flour is cooked with fat to create a base that thickens and adds flavor to many classic sauces.
Recipes Specifically Calling for Cornstarch
  • Puddings and Pie Fillings: Cornstarch is ideal for creating thick, smooth, and clear fillings.
  • Velveting in Asian Cooking: Meat or fish is coated with cornstarch before cooking to provide a tender texture.
  • Fruit Glazes: Because it’s clear and thickens effectively at low temperatures, cornstarch is perfect for shiny, thick glazes over fruit tarts.