Do you put eggs in custard?: The Nutritional and Culinary Truth

November 9, 2025 •

4 min read

Eggs are a powerhouse of essential nutrients, with studies showing they are a source of high-quality protein and vitamins. The culinary world's fascination with this nutritional profile is evident in classics like custard, prompting the question: Do you put eggs in custard? The answer lies in both tradition and modern dietary science.

Quick Summary

Traditional custard relies on eggs for its signature thick, velvety texture and nutritional value. Understanding the protein coagulation process is key to mastering egg-based custard, while many alternatives use starches or plant-based ingredients to mimic the classic dessert.

Key Points

Eggs are fundamental: In traditional recipes, eggs are the primary thickening agent in custard, with their proteins coagulating under gentle heat to create a gel-like structure.
Egg yolks provide richness: Using egg yolks instead of whole eggs results in a richer, smoother custard due to the emulsifying fats and lecithin found in the yolk.
Custard can be eggless: For vegan diets or egg allergies, alternatives use starches like cornstarch, arrowroot, or even silken tofu to achieve a thickened consistency.
Nutritional profiles differ: Egg-based custard is a superior source of high-quality protein and micronutrients like choline, while eggless versions lack these unless fortified.
Temperature control is critical: The key to a smooth, lump-free egg custard is cooking it slowly and evenly over low heat to prevent the eggs from scrambling or curdling.
Strain for the perfect texture: Passing the finished custard through a fine sieve ensures a perfectly smooth and silky texture, removing any tiny lumps.

The Science Behind Egg Custard

At its core, a true custard is defined by its use of eggs as a primary thickening agent. The eggs contain proteins that, when heated, coagulate to form a gel-like structure. This transformation gives custard its characteristic smooth, velvety texture. However, the process is delicate and requires careful temperature control to prevent the proteins from over-coagulating, which results in a curdled or grainy mixture.

The Critical Role of Egg Yolks

While some recipes use whole eggs, traditional and rich custards often rely heavily on egg yolks. This is because egg yolks are rich in fats and emulsifiers, particularly lecithin. This emulsifying property helps to create a smoother, richer mouthfeel and also contributes to a stable mixture. The fats in the yolk add to the decadent flavor profile and help prevent the proteins from setting too quickly. Egg yolks also provide a golden color that is highly desirable in classic custard.

Egg Yolks vs. Whole Eggs

Choosing between egg yolks and whole eggs significantly impacts the final texture of the custard. Egg whites contain more water and proteins that can lead to a firmer, sometimes grittier texture if not handled correctly. The additional protein from egg whites can also cause the custard to set more rigidly. For a light, pourable custard like crème anglaise, yolks are generally preferred for their rich, smooth finish. For a baked, set custard like a flan, whole eggs are often used to create a sturdy, sliceable structure.

Nutritional Comparison: Egg vs. Eggless Custard

The choice between an egg-based and an egg-free custard has clear nutritional implications. Egg-based custards generally contain more high-quality protein and a broader spectrum of micronutrients. Eggless versions, relying on starches like cornflour, trade these benefits for potential allergen-free or vegan-friendly profiles.


Nutrient Aspect	Egg-Based Custard	Eggless Custard (Starch-Based)
Protein	High-quality, complete protein source from eggs, essential for muscle maintenance.	Lower in protein, depending on the type of milk used. Plant-based milks may offer some protein.
Vitamins	Rich source of vitamins A, D, E, K, and B vitamins, particularly B12 and folate.	Lacks the vitamins naturally found in eggs. Fortified plant-based milks may offer some B vitamins and vitamin D.
Minerals	Contains significant amounts of iron, zinc, selenium, and choline.	Often lower in minerals unless fortified plant milk is used.
Fats	Higher in monounsaturated fats from egg yolks, contributing to richness.	Fat content varies greatly depending on the type of milk (e.g., full-fat coconut milk vs. almond milk).
Allergens	Contains eggs, a common allergen.	Generally egg-free, suitable for those with egg allergies.
Dietary Suitability	Not suitable for vegan or egg-free diets.	Suitable for vegan and egg-free diets when made with plant-based milk.

Healthier Custard Alternatives

For those seeking a healthier dessert option or adhering to dietary restrictions, several alternatives to traditional egg custard exist. These options utilize different ingredients to achieve a creamy, thickened consistency.

Vegan and Plant-Based Options

For a vegan custard, the eggs are typically replaced with a thickening agent such as cornstarch, arrowroot powder, or agar-agar. Plant-based milks like soy, oat, or coconut milk are used in place of dairy. Some tips for preparing vegan custards include:

Thickening agent: Whisk cornstarch or arrowroot with a small amount of cold plant-based milk to form a slurry before adding to the heated milk. This prevents lumps.
Flavoring: Vanilla extract or a vanilla bean is a classic choice. A pinch of turmeric can be added for a golden hue.
Richness: Using a creamy plant-based milk like full-fat coconut milk can replicate the richness provided by egg yolks.

Other Thickening Agents

Besides eggs, other agents can be used to thicken custard, often in combination with eggs to create a more stable result.

Cornstarch or Flour: Starch molecules absorb water and swell when heated, creating a thick, stable texture that can prevent curdling. Pastry cream (crème pâtissière) is a classic example that uses both eggs and starch.
Gelatin: This can be used to create a set custard, known as crème anglaise collée, without relying on the eggs to provide the firm structure.
Tofu: For a high-protein, egg-free option, silken tofu can be blended into a creamy base for baked custards like pumpkin pie.

Key Tips for Making a Perfect Egg Custard

Temper your eggs: Slowly whisk a small amount of the hot milk mixture into your whisked eggs to gently raise their temperature. This prevents the eggs from scrambling when they are added to the saucepan.
Cook slowly and gently: Always use low to medium-low heat and stir constantly. A double boiler or bain-marie (water bath) can help regulate the heat more effectively for baked custards.
Strain for smoothness: After cooking, pour the custard through a fine-mesh sieve to remove any small lumps or overcooked egg proteins. This ensures a silky-smooth finish.
Avoid the 'skin': To prevent a skin from forming on top as it cools, press a sheet of plastic wrap directly onto the surface of the custard.
Use fresh ingredients: The quality of your milk, cream, and especially your eggs, will impact the final flavor and texture of your custard.

Conclusion

So, do you put eggs in custard? The answer is a resounding yes for any traditional custard recipe, as eggs provide the essential protein structure, rich flavor, and velvety texture that define the dessert. However, dietary preferences and nutritional goals offer a diverse landscape of alternatives. Whether you opt for the nutrient-rich, classic egg custard or a delicious, dairy-free version, understanding the science of the ingredients allows for a more controlled and successful outcome. The key to a great custard, with or without eggs, lies in careful technique and quality ingredients. For a deeper dive into the nutritional composition of eggs, you can explore detailed research from the National Institutes of Health.(https://pmc.ncbi.nlm.nih.gov/articles/PMC6470839/)

Frequently Asked Questions

Eggs are used to thicken custard because the proteins in them, particularly in the yolks, coagulate when heated gently. This process causes the proteins to unwind and link together, forming a gel-like structure that thickens the liquid.

Egg-based custard offers a complete, high-quality protein source and is rich in vitamins like D and B12, and minerals such as choline. Eggless custards typically lack this nutritional density unless fortified ingredients are used.

Yes, but using whole eggs will result in a firmer texture due to the added protein from the egg whites. For a richer, smoother custard, just the yolks are generally preferred.

Prevent curdling by cooking the custard slowly over low, gentle heat and stirring constantly. Tempering the eggs by slowly whisking in some of the warm milk mixture before adding them to the saucepan is also crucial.

For vegan custard, common substitutes for eggs include thickening agents like cornstarch, arrowroot powder, or agar-agar, combined with a plant-based milk such as soy, oat, or coconut milk.

Besides adding sweetness, sugar also stabilizes the egg proteins during heating, helping to prevent them from coagulating too quickly and curdling. It creates a smoother, more even thickening process.

A water bath, or bain-marie, is recommended for baked custards because it insulates the dish from direct heat. This allows the custard to cook more evenly and at a lower, more controlled temperature, preventing the edges from overcooking and becoming rubbery.