Can you have custard on keto? A guide to low-carb dessert alternatives

November 6, 2025 •

3 min read

A single cup of traditional custard can contain over 25 grams of carbohydrates due to its high sugar and milk content. This places it firmly outside the acceptable range for a ketogenic diet, which requires keeping daily net carbs below 50g for most people. But can you have custard on keto? Yes, by making simple, strategic ingredient swaps, you can create a delicious, creamy custard that perfectly fits your low-carb lifestyle.

Quick Summary

Traditional custard is high in carbs and sugar, but a keto-friendly version is possible with the right ingredient substitutions. Learn how to make creamy, low-carb custard that satisfies sweet cravings while supporting your ketogenic goals.

Key Points

Traditional Custard is Not Keto-Friendly: Due to high amounts of sugar and lactose in milk, conventional custard contains too many carbohydrates for a ketogenic diet.
Keto Custard Relies on Ingredient Swaps: To make custard keto-compliant, replace sugar with low-carb sweeteners and cow's milk with heavy cream, coconut milk, or almond milk.
Essential Keto Sweeteners: Monk fruit, stevia, erythritol, and allulose are zero or low-net-carb sweeteners suitable for making keto custard.
Proper Technique Prevents Scrambled Eggs: Tempering the eggs by slowly incorporating the heated liquid is crucial for a smooth, silky texture.
Customization is Easy: The base keto custard recipe can be flavored with cocoa powder, pumpkin spice, or other extracts, and topped with berries or whipped cream.
High in Healthy Fats: Keto custard utilizes high-fat bases like heavy cream and egg yolks, which aligns with the macronutrient ratio of a ketogenic diet.

The Fundamental Conflict: Custard and the Ketogenic Diet

The ketogenic diet focuses on low carbohydrate intake and higher fat consumption to achieve a state of ketosis, where the body uses fat for fuel. Traditional custard, made with sugar and milk, is high in carbohydrates and therefore not suitable for a keto diet. The challenge for keto dieters is to recreate the custard experience using low-carb ingredients.

The Nutritional Red Flags in Standard Custard

Traditional custard's high carbohydrate count comes from added sugars and the natural sugars (lactose) found in milk. Ingredients like cornstarch, often used as thickeners in conventional custard mixes, are also high in carbohydrates and should be avoided on a keto diet. Replacing these high-carb components is key to making custard keto-friendly.

Creating Keto-Friendly Custard: Essential Swaps

To make a keto-compliant custard, high-carb ingredients must be replaced with low-carb, high-fat alternatives.

Choosing Your Base

Instead of cow's milk, which is high in lactose, suitable keto bases include heavy cream for richness, full-fat canned coconut milk, or unsweetened almond milk for dairy-free options. A mix of heavy cream and unsweetened nut milk can provide a good balance.

Selecting the Right Sweeteners

Traditional sugar is replaced with zero or low-carb sweeteners. Good choices include erythritol, monk fruit, stevia, and allulose. It's advisable to avoid sugar alcohols like maltitol, which can cause digestive issues and have a higher glycemic impact.

Mastering the Thickening Process

Eggs are a traditional binder and remain essential in keto custard. Using whole eggs and extra yolks adds richness. Gently heating the mixture, often in a water bath, helps prevent scrambling. A small amount of xanthan gum can be used for extra thickness and a smoother texture.

How to Prepare a Basic Keto Custard

Here is a simple recipe for making low-carb custard, focusing on the tempering technique for a smooth result:

Ingredients:

Heavy whipping cream
Unsweetened almond milk
Large egg yolks
Keto-friendly sweetener (e.g., erythritol or monk fruit blend)
Vanilla extract
Pinch of salt

Instructions:

Preheat the oven and prepare a water bath for the ramekins.
Gently heat the cream and almond milk in a saucepan.
Whisk together egg yolks, sweetener, vanilla, and salt in a separate bowl.
Temper the egg mixture by slowly whisking in a small amount of the hot cream mixture, then gradually add the rest.
Pour the mixture into ramekins.
Carefully place the ramekins in the water bath in the oven.
Bake until the edges are set and the center is slightly jiggly.
Cool completely and then chill in the refrigerator to set fully.

Comparison of Traditional vs. Keto Custard


Feature	Traditional Custard	Keto Custard	Reason for Difference
Sweetener	Refined sugar	Erythritol, Monk Fruit, Stevia, Allulose	Keto diet restricts sugars to maintain ketosis.
Carbohydrate Content	High (often >25g per serving)	Very Low (<5g net carbs per serving)	Swapping sugar and milk reduces carb load.
Fat Source	Often whole milk, lower in fat content	Heavy cream, coconut milk, egg yolks	Keto requires high fat to provide energy.
Dairy	Cow's milk is standard	Heavy cream, unsweetened nut milks (almond, coconut)	Lactose in cow's milk is a carb source.
Thickener	Cornstarch or flour often used in mixes	Egg yolks, heavy cream, sometimes xanthan gum	Cornstarch and flour are high in carbs.
Impact on Ketosis	Disrupts ketosis due to high sugar/carb content	Supports ketosis by providing high fat and low carbs	Ingredients are aligned with keto macro goals.

Customizing and Enjoying Your Keto Custard

Keto custard can be easily customized with various flavors and toppings.

Flavorful Variations

Adding unsweetened cocoa powder creates chocolate custard. Pumpkin puree and spice are great for a fall theme. Instant coffee granules can be added for a mocha flavor. Using a coconut milk base provides a tropical taste.

Serving Suggestions and Toppings

Keto custard can be enjoyed plain or topped with nutmeg, cinnamon, sugar-free whipped cream, keto-friendly berries like raspberries or blackberries, chopped nuts, or toasted seeds for added texture and healthy fats.

A Satisfying and Sensible Keto Dessert

While traditional custard isn't keto-friendly, a homemade low-carb version is a delicious and suitable dessert. By substituting high-carb ingredients with keto alternatives, you can enjoy a creamy custard without compromising your dietary goals. With the right recipe and understanding of ingredient swaps, you can have a decadent treat while maintaining ketosis.

Frequently Asked Questions

The main difference is the ingredients. Regular custard uses high-carb ingredients like sugar and milk, while keto custard replaces these with zero-carb sweeteners and low-carb, high-fat alternatives such as heavy cream, unsweetened almond milk, or coconut milk.

Not all sugar-free sweeteners are created equal. It's best to use ones with a minimal glycemic impact, like erythritol, monk fruit, stevia, or allulose. Avoid highly processed sweeteners or those with high-carb fillers that could interfere with ketosis.

Baking the custard in a water bath, or bain-marie, provides a gentle, moist, and even heat source. This prevents the edges from cooking too fast and the center from curdling, ensuring a silky-smooth, evenly set final product.

For a thicker custard, especially when using milk substitutes, you can add a small amount of xanthan gum (¼ to ½ tsp) to the mixture before cooking. Ensure you are also cooking it over low heat and stirring continuously until it coats the back of a spoon.

Yes, you can substitute heavy cream with full-fat canned coconut milk, coconut cream, or a full-fat unsweetened almond milk for a delicious dairy-free version. Using coconut milk will give it a distinct tropical flavor.

Generally, keto custard is not suitable for freezing. The delicate texture can be compromised during the freezing and thawing process, causing it to become watery or grainy. It is best enjoyed fresh or stored in the refrigerator for up to 4 days.

Some sweeteners, particularly stevia and erythritol, can have a cooling or bitter aftertaste in large quantities. To avoid this, use a blend of sweeteners (like monk fruit and erythritol) and start with a smaller amount, tasting the mixture before adding the eggs.