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Egg Substitutes

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Have any of your friends or family members ever had an allergic reaction to eggs? In this science project idea, you'll investigate how to modify recipes so that even egg-allergic friends and family members can enjoy them.


Areas of Science
Time Required
Long (2-4 weeks)
Material Availability
Readily available
Low ($20 - $50)
Adult supervision required when using the oven, stove, blender, or chopping ingredients.

Kristin Strong, Science Buddies


In this science fair project, you will evaluate the ability of egg substitutes to mimic the binding, leavening, or thickening properties of eggs in baking and cooking.


Egg allergy affects up to 2 percent of all children and is second only to milk protein as the top allergen in children. Reactions to eggs can be mild to severe. Some children outgrow their allergy by the time they reach elementary school, but in the past two decades, allergists have reported that greater numbers of children are experiencing egg allergy into their high school years and beyond.

If you, a friend, or a family member has experienced egg allergy, then you know how difficult it is to eat out in restaurants, or to find processed foods from grocery stores without eggs. Egg proteins are hidden under many different chemical names in foods. You can find egg proteins in:

For safety, families who experience egg allergies must prepare many foods from scratch at home. In this science project, you'll explore how to modify recipes so that foods that require eggs are safe to eat for egg-allergic friends and family members.

Eggs are used in baking and cooking in three key ways:

  1. As a binder (to hold other ingredients together)
  2. As a leavening agent (to make a food rise)
  3. As a thickener (to make a food or sauce thicker)

How can you tell the purpose of an egg in your recipe? By looking at the other ingredients. If, for example, there is little other liquid in the recipe, then you know the egg is being used to add moisture. If there is no baking powder or baking soda, but there is an acid (like lemon juice, orange juice, or vinegar), then you know the egg is being used as a leavening agent. If there is nothing else in the recipe to act as a "glue," such as flour or nuts or bread crumbs, then you know the egg is likely serving as a binder.

For this science project, you'll investigate egg substitutes-ingredients that mimic the function of egg. Table 1 shows some common egg substitutes for the three functions of egg that you'll be focusing on: binding, leavening, or thickening.

Binder Leavening Agent Thickener
Ground flax seed Baking powder + Extra oil Applesauce
Gelatin Vinegar Tapioca flour
Banana Lemon juice + Baking soda Banana
Silken tofu Orange juice + Baking soda Tofu
Arrowroot powder Buttermilk + Baking soda Fruit puree
Agar powder   Corn starch

Table 1. Common substitutes for egg, based on the function of egg in a recipe.

The substitute you choose to try for your recipe will depend upon the egg function you are trying to replace, and the taste you are trying to achieve (for example, would a fruity tasting substitute be a good combination with the other ingredients, or would a bland, neutral-tasting substitute work better?). Let's get cooking!

Terms and Concepts



  • This source provides information on the amount of egg substitute you should use to replace each egg in a recipe. It also describes any special preparation that is required to prepare the substitute for use in a recipe:
    The Cooking Inn. (2008). Egg Substitutes. Retrieved March 27, 2008.

Materials and Equipment

Experimental Procedure

  1. Select which egg function you want to investigate: binding, leavening, or thickening.
  2. Select a test recipe that uses egg as a binder, as a leavening agent, or as a thickener. Below are a few example recipes.

    Egg as a Binder Egg as a Leavening Agent Egg as a Thickener
    Meatloaf Cakes Custard
    Quick breads Cupcakes Lemon sauces
    Cornbread Meringues 

  3. Choose several egg substitutes from Table 1 to test. Be sure to select substitutes only from the column of the function your egg substitute will perform in the recipe.
  4. Make a data table to record your measurements from the tests, as shown below:

    Egg Substitute 1 Substitute 2 Substitute 3
    Trial 1   
    Trial 2   
    Trial 3    
    Sum of Trials   
    Average of Trials   

  5. Make your recipe three times with egg, and then three times each for each of the egg substitutes that you are testing. For recipes that create individual servings, like cookies and cupcakes, you need to use an ice cream scoop, melon baller, or measuring cup so that the servings are uniform.
  6. After each trial, measure and record in your lab notebook the amount of binding, leavening, or thickening (depending on which function you chose) in one of each of the finished products, as described below:
    1. If you're measuring binding, cut the product in half on a plate or paper towel, or cut a uniform slice off the product. Count the number of crumbs after the cut. Use a clean paper towel or plate and a clean knife for each test. Take photos for your display board, if desired.
    2. If you're measuring leavening, measure the height of the product at its highest point, as shown in Figure 1. Take photos for your display board, if desired.

      The height of two muffins are measured against a wall

      Figure 1. Example of how to measuring leavening.

    3. If you're measuring thickening, stack the two books on top of each other. Place 1 teaspoon of your thickened sauce on a plate. Tilt the plate by resting the plate edge on top of the two books. Use the same books for each trial so that the amount of tilt (the slope of the plate) is a constant. Wait 30 seconds, and then lay the plate flat again. Measure the distance the sauce has run on the plate, as shown in Figure 2. Be sure to clean the teaspoon and the plate after each trial. Temperature affects viscosity (which is how the sauce resists flow), so make sure the sauces are at the same temperature when you test them (for example, room temperature or refrigerated). Take photos for your display board, if desired.

      The distance two sauces slide across a plate is measured

      Figure 2. Example of how to measure thickening.

  7. Plot the average measures of binding, leavening, or thickening for egg and for each substitute that you tested.
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Ask an Expert

Do you have specific questions about your science project? Our team of volunteer scientists can help. Our Experts won't do the work for you, but they will make suggestions, offer guidance, and help you troubleshoot.


  • In addition to conducting the substitute performance tests described in the experimental procedure, conduct taste tests and then score ease of preparation for each of your trials. Then create a composite score for each trial that includes taste, ease of preparation, and performance. For example, score taste tests and ease of preparation from 1 (worst) to 5 (best) and record your scores in data tables like the ones below:

    Taste score Egg Substitute 1 Substitute 2Substitute 3
    Trial 1    
    Trial 2    
    Trial 3     
    Sum of Trials    
    Average of Trials    

    Ease of Preparation Egg Substitute 1 Substitute 2Substitute 3
    1 (easy) to 5 (difficult)    

    • Give each of these results a 20 percent weight in your composite score so they contribute (at most) 1 point to the total composite score.
    • Then compute a performance ratio that compares the average binding, leavening, or thickening performance of each substitute to the performance of egg in a ratio:
      • For binding, the ratios are the average number of crumbs for the recipe with egg divided by the average number of crumbs for the recipe with egg substitutes.
      • For leavening, the ratios are the average height of the recipe with egg substitutes divided by the average height of the recipe with egg.
      • For thickening, the ratios are the average drip length for the recipe with egg divided by the average drip length for the recipe with egg substitutes.
    • Create your composite score for each trial:
      Composite Score = 0.20 x (Taste test score) + 0.20 x (Ease of preparation score) + Performance ratio
  • Think of a way to measure the moisturizing and glazing functions of egg so that egg substitutes for those (shown below) can be tested, too.

    Adding Moisture Glazing
    Applesauce Butter
    Banana Margarine
    Fruit juice Fruit juice
    Soy milk Water


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MLA Style

Science Buddies Staff. "Egg Substitutes." Science Buddies, 23 June 2020, https://www.sciencebuddies.org/science-fair-projects/project-ideas/FoodSci_p002/cooking-food-science/egg-substitutes. Accessed 6 Dec. 2023.

APA Style

Science Buddies Staff. (2020, June 23). Egg Substitutes. Retrieved from https://www.sciencebuddies.org/science-fair-projects/project-ideas/FoodSci_p002/cooking-food-science/egg-substitutes

Last edit date: 2020-06-23
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